The world of photography is full of words and phrases that can be confusing for new photographers, so PetaPixel has put together a complete glossary of everything you may want to know the meaning of if you’re just getting started.

You can use the index below to jump to a particular section. Certain terms will also link out to more thorough guides that will provide you with a deeper understanding of that topic.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  0-9

A

Active Autofocus. An autofocus system in which the camera emits a red beam that bounces off the subject, returns to the camera, and is detected in order to determine the distance from the camera to the subject. The camera then uses this reading to precisely adjust focus and lock it onto the subject.

Adobe. An American software company based in San Jose, California. Many of its flagship products, including the image editing software Adobe Photoshop, are widely used by photographers, videographers, and creatives across a wide range of industries.

Adobe Camera Raw. Also known as ACR, it is an Adobe Photoshop plug-in that lets you import, process, and enhance raw photographs without going through Adobe Lightroom.

AE Lock. Autoexposure lock is a camera function that allows the users to lock the current exposure settings. This enables the photographer to shoot photos without the camera recalculating the necessary settings for optimal exposure before every shot.

AF Lock. Autofocus lock is a camera feature that allows a photographer to freeze the current focus point of the lens, enabling them to shoot a photo at any time independent of whether the camera determines it has achieved correct focus.

Ambient Light. Any light in a scene that the photographer did not introduce artificially. This can include both natural light from the Sun as well as artificial light already illuminating a location.

Angle of View (AOV). Another term for field of view.

Aperture. The opening of the diaphragm within a lens that light passes through on its way into a camera. This is one of the fundamental settings for controlling exposure and a component of the Exposure Triangle. Usually measured and expressed as a number known as the f-number of f-stop.

Aperture Priority. A camera exposure mode in which the photographer sets the aperture and the camera automatically sets the shutter speed in order to achieve optimal exposure based on lighting conditions detected by the built-in light meter.

APEX. Short for Additive System of Photographic Exposure. A system for simple exposure computation first proposed in the 1960 ASA standard regarding monochrome film speed. While APEX failed to become a fundamental standard in the camera industry, its use of Av and Tv to refer to aperture and shutter speed live on in modern cameras.

APS-C. Advanced Photo System type-C is a format for digital image sensors that is roughly the same dimensions as the Advanced Photo System (APS) film negative in its Classic (C) format. It measures 25.1×16.7mm with an aspect ratio of 3:2. Commonly found in digital cameras, the format is smaller than standard 35mm film, so it is known as a “cropped frame” sensor, usually with a crop factor of 1.5x or 1.6x.

APS-H. Advanced Photo System type-H is a format for digital sensors that is based on the dimensions of Advanced Photo System (APS) film negative in its High Definition (H) format. It measures 30.2×16.7mm with an aspect ratio of 16:9. Not commonly found in modern digital cameras, APS-H has a crop factor of about 1.25x or 1.3x compared to standard 35mm film.

Archival. The quality and ability of a photo to remain unchanged in appearance for an extended period of time. Can refer to data storage technologies for digital images or paper, ink, and storage qualities for photographic prints.

ASA. Short for American Standards Association. The standards body that defined the ASA system for rating the speed sensitivity of photographic emulsions. The private non-profit organization has since been renamed to American National Standards Institute (ANSI). In 1974, ASA and DIN were combined into the ISO standards used by photographers today.

Aspect Ratio. The ratio of an image’s width compared to its height. Typically expressed as the two numbers separated by a colon. Common aspect ratios found in film and digital photography include 4:3, 3:2, 16:9, 5:3, 5:4, and 1:1.

Aspherical Lens. A type of optical lens in which the surface curves are not portions of a sphere. Compared to a traditional non-aspheric lens, the more complex shape of aspherical lenses allows light rays to more precisely converge onto a single focal point, reducing various types of optical aberrations. Typically found in higher-end camera lenses geared toward professional photographers.

Astrophotography. Astronomical photography has to do with shooting photos of the night sky or anything found within it, including space objects and events. Advancements in camera, computing, and telescopic technologies and the accompanying reduction in prices have opened the door to astronomical photos that were impossible just years ago, leading to an explosion in highly-detailed space photos from amateur astronomers and photographers.

Autofocus. A system in a camera that automatically focuses a lens on a selected point or area within a scene. Achieved actively (e.g. with sound or light), passively (e.g. with phase or contract detection), or in a hybrid way through a variety of means, but generally involving a sensor, controller, and motor.

B

Back Button Focus. A camera technique in which the autofocus function is moved from the shutter button to a button on the back of the camera. This gives the photographer more control over the photography process as different fingers will be responsible for exposing photos and autofocusing.

Background. Any part of a scene that is behind the main subject, located at a farther distance than the subject from the camera. The background provides context for the location of a photo, but it can also be blurred using a shallow depth of field to force a viewer to focus on the subject, something often done in portrait photography.

Backlight. When the primary light source, whether natural or artificial, is located behind the subject or in the background of a scene. The resulting look is often dramatic and may involve a glowing edge around the subject and/or the subject rendered as a silhouette (if the backlight is at least 16 times more intense than the key light).

Barrel Distortion. A type of distortion in which straight lines in a scene appear to bend outward away from the center of the image as if you are looking at the outside of a barrel. This effect can often be seen when using wide-angle lenses.

Blown-Out Highlights. When overexposure occurs in the brightest parts of a photo, causing details in those areas to be forever lost due to most or all the pixels rendering as pure white. This is also known as clipping.

Blue Hour. The brief period of time immediately before sunrise or after sunset in which the Sun is still below the horizon, causing the sky to have a bluish color cast. Like golden hour, blue hour provides a soft and pleasant quality of light that is valued by photographers and other artists.

Bokeh. The aesthetic quality of the blur, most famously circular and caused by light sources, found in the out-of-focus areas of photos that are generally captured with a shallower depth of field. Different lenses produce different bokeh that is subjectively more or less pleasing than others, and high-end lenses with large maximum apertures are often praised for their bokeh quality. Bokeh is often found in portraits shot with a narrow depth of field in order to draw focus to the subject and eliminate distracting backgrounds.

Bracketing. A technique in which a photographer captures multiple photos of exactly the same scene with different camera settings. The frames could, for example, use different exposure, aperture, focus, flash, ISO, white balance, and more. Some cameras may have auto-bracketing features for some settings. The photographer can choose the best photo from the resulting set or combine (or stack) them for various purposes (such as focus stacking in macro photography).

Brenizer Method. Also referred to as a “bokeh panorama,” this is a technique popularized by wedding photographer Ryan Brenizer that involves shooting multiple “zoomed-in” photos of a wider scene using a fast normal-to-telephoto lens. By stitching together the photos into a single wide-angle panorama with a shallow depth of field, a photographer can mimic the look of large-format photography.

Buffer. The internal memory (RAM) of a camera that temporarily stores captured image data before the photo is saved to a memory card. The storage capacity of the buffer plays a role in how many photos can be captured in a burst before the camera needs to slow down and clear space in the buffer to make room for a new photo.

Bulb Mode. A camera mode that exposes a photograph for as long as the shutter button is depressed. Most cameras have a maximum shutter speed of 30 seconds, but Bulb mode can be used to capture ultra-long exposure photos with as long of an exposure as the photographer desires.

Burst Mode. Also known as continuous shooting mode, this is a camera feature that allows multiple photos to be captured in rapid succession, generally by holding down the shutter button. Cameras advertise a maximum frame-per-second (FPS) rate a camera can achieve in burst mode, and the burst rate is the number of frames that can be initially captured at the maximum FPS before the internal buffer fills up and the rate slows down.

Burst Rate. The number of frames that a camera can capture before the buffer is filled. The number of frames captured per second will then slow down to the rate at which the camera can process each photo in the buffer and move it to the memory card, freeing up space for a newly captured photo.

C

Cable Release. A cable that plugs into a camera on one end and which has a shutter button on the other. It is used to remotely trigger the shutter of the camera without the photographer having to touch the camera itself, eliminating the issue of vibrations that reduce image sharpness. Useful when shooting long exposure photos, particularly in bulb mode.

Camera. A device that is capable of capturing an optical image on a light-sensitive surface. A camera (from “camera obscūra”, Latin for “dark chamber”) is at its core a light-sealed box that takes in light as its input and produces a photograph as its output. Light may enter the camera through anything from a pinhole to an expensive lens made of metal, plastic, and/or glass. The light-sensitive surface may be anything from a coated metal sheet to photographic film to a digital sensor. The art of photography is the practice of using a camera to create photographs.

Camera Body. Refers to the main physical device that is used to capture photos. While it can have a built-in lens, it generally refers to a camera itself without an attached lens. While camera bodies were purely mechanical devices in earlier periods of photography and during the age of photographic film, modern digital camera bodies also contain high-tech electronics, digital displays, and silicon image sensors.

Camera Obscura. Latin for “dark chamber,” this was originally a dark room that had a hole or lens that allowed light from the outside world to be projected onto an inner wall or surface. While the color and perspective of the outdoor scene are the same in the projected image, the image itself is inverted upside-down and reversed left and right. The term camera obscura is also used to refer to smaller constructed spaces or boxes that operate with the same principle. By adding a light-sensitive surface to a camera obscura, a photo can be made using the projection, thereby turning the camera obscura into a camera.

Camera Shake. The unintentional movement of a camera during the exposure of a photograph, generally resulting in a photo that is less sharp and more blurry than desired. This can be caused by unsteady hands when shooting handheld, the force of pressing the shutter button, or environmental causes such as wind blowing a tripod-mounted camera. The combination of using a remote shutter release and a sturdy tripod can greatly reduce or eliminate camera shake.

Candid Photograph. Any photograph captured without the subject(s) in the frame posing for the image. A photographer aiming to create photos in this style will generally capture unplanned moments in life as it occurs without stopping or directing the people being photographed. Subjects may or may not be aware of the photos being made.

Catchlight. A light source that appears as a specular highlight in a subject’s eyes. Photographers commonly use a light’s positions and settings for this end result, transforming eyes from having a flat and lifeless appearance to having a glint that adds a spark of life.

CCD Sensor. A charge-coupled device sensor is one of the two major types of semiconductor image sensors, with the other being CMOS. Advantages typically include a global shutter (all pixels are exposed at the same time), high resolution/sensitivity (due to pixels not having to share space with the amplifiers), and high-quality/low-noise. Disadvantages include high power consumption and high cost (a special manufacturing process is needed).

Chimping. The colloquial term used to refer to the act of bringing a camera — generally a DSLR — away from the eye after every exposure to review the resulting photo immediately on the rear display. Although the term is often used in a derogatory sense, frequently reviewing photos after they are captured to check things like settings, exposure, and composition. Mirrorless cameras allow photos to be reviewed immediately within the electronic viewfinder itself, eliminating the need to “chimp.”

Chromatic Aberration Also called “color fringing,” this is a color distortion that occurs when a lens fails to focus all colors to the same point. It appears as an outline or fridge of color in areas of an image where there is high contrast between light and dark objects.

Cinemagraph Coined by photographers Kevin Burg and Jamie Beck in 2011, this is a still photo that contains looping movement in a particular minor portion of the image. The result is what looks like a still photograph that has subtle motion that helps bring it to life. The name refers to the combination of a moving picture (cinema) with a still picture (photograph).

Circular Polarizer Filter Abbreviated CP or CPL, this is a type of filter that attaches to a lens and cuts down on glare and reflections. Photographers may employ it when shooting things like water, glass, foliage, and cloudy skies. The front part of the filter can be rotated to control the polarization effect.

Clipping The loss of information that occurs when highlights are overexposed or shadows are underexposed in a photo, resulting in regions that are captured as pure white or pure black, respectively, without any detail. Histograms can be used in cameras and software to identify and avoid clipping. Photo processing and editing programs also commonly have clipping indicators to help photographers easily identify areas where information is being discarded.

CMOS Sensor A complementary metal–oxide–semiconductor sensor is the dominant type of image sensor found in modern digital cameras (the other being CCD). Advantages include readout speed, low power consumption, and low cost (it uses traditional chipmaking processes). Disadvantages include rolling shutter (pixels are exposed line by line) and lower sensitivity (each pixel site shares space with an amplifier).

Cold Shoe. A bracket designed to hold a camera flash or other accessory. While a hot shoe has electrical contacts that allow a camera to communicate with the accessory (e.g. fire a flash unit), a cold shoe does not contain electronics and therefore is used solely for mounting an accessory and holding it in place.

Compact Camera. Another name for the point-and-shoot camera.

Composite Photograph. A photo that is the result of combining two or more different photos into a single image that is blended in some way. Creating a realistic and/or seamless composite generally requires a great deal of both skill and time.

Composition. How the visual elements in a photo are arranged within the frame. Paying careful attention to how a subject and scene are framed allows the photographer to capture an image that can do things such as direct the viewers’ eyes, be more visually appealing, tell a story, elicit a feeling or emotion, and more. There are various “rules of thumb” that aid beginning photographers in creating good compositions.

Computational Photography. The use of algorithms, AI, and computer processing to enhance or manipulate images, producing results that go beyond what traditional photography can create with light, lenses, sensors, and physics. Computational photography has become increasingly important in the age of smartphone cameras due to the size constraints of the lenses and sensors, though its technologies are being applied to standalone cameras as well.

Continuous Shooting. Another name for burst mode.

Contrast. The difference between a certain aspect of elements in a photo. This could be the tonal contrast between the lightest tones and the darkest tones in an image, or it could be the color contrast between opposing colors in the frame.

Contrast Detection Autofocus. A common camera autofocus method that uses the contrast between edges in a scene to achieve sharp focus. Since the contrast of two side-by-side pixels should increase if focus increases, the camera simply adjusts the lens’s focus back and forth until maximal contrast is settled upon.

Copyright. The legal ownership of a creative work. A form of intellectual property that gives the creator the exclusive right, for the duration of the copyright, to copy and distribute the work they have created. A photographer automatically owns the copyright immediately after they shoot a photo, but there are advantages to officially registering your works with the US Copyright Office.

Copyright Infringement. When a copyrighted photograph or any other creative work is reproduced, distributed, performed, publicly displayed, or made into a new derivative work without the permission of the owner of the copyright. In the photo industry, this is often when a photographer’s photo is published online or used for commercial purposes such as advertising without that photographer’s permission.

Cropping. The act of removing unwanted outer edge portions of a photo to create a resulting photo that represents a subsection of the full, original image. Unlike resizing a photo, which changes the number of pixels while keeping the original composition, cropping trims parts of a photo — typically unnecessary areas — and creates a new composition. This can be done to change the aspect ratio, better focus on a subject, and/or draw the viewers’ eyes to a particular portion of the frame.

Crop Factor. The ratio of a digital camera’s sensor size relative to the “full frame” size (36×24mm) popularized by 35mm film. For example, a smaller APS-C format image sensor typically has a crop factor of 1.5x or 1.6x. This is also known as the focal length multiplier since multiplying a lens’s focal length by a smaller sensor’s crop factor will result in a focal length with an equivalent field of view on a full-frame sensor. For example, a 50mm lens on a 1.6x crop sensor will have a field of view equivalent to an 80mm lens on full frame.

Crop Sensor. Any digital sensor that is smaller than 35mm full frame, which is considered to be the reference size when discussing image sensors. Crop sensors have a crop factor depending on the ratio between their size and full frame.

Cross Processing. Intentionally processing one type of photographic film in a chemical solution that is intended for another type — in other words, using the “wrong” developer. This can result in unpredictable shifts in the color and contrast of the photo that can be desirable for artistic purposes.

Crushed Shadows. When underexposure occurs in the darkest parts of a photo, causing details in those areas to be forever lost due to most or all the pixels rendering as pure black. This is also known as clipping.

D

Daguerreotype. The first publicly available photography process as well as the physical photo plates created through the process. Invented by French photographer Louis Daguerre and introduced in 1839, the daguerreotype became a dominant photography process in the mid-1800s.

Darkroom. A completely light-sealed room used by film photographers to handle light-sensitive photography materials and to do things such as make photographic prints. The room is typically illuminated with a safelight, which emits light at wavelengths that are visible to the human eye but photosensitive materials are not sensitive to.

Depth of Field (DoF). The distance between the nearest and farthest objects in a photo that are in focus by being acceptably sharp. A shallow depth of field can result in considerable blurring in front of and behind the subject that is focused on, while a wide/deep depth of field can render more (or all) of a scene in sharp focus.

Diaphragm. The component in a camera lens that uses a configuration of overlapping metal blades, called the iris, to enlarge or shrink the size of the opening in the middle, called the aperture, in order to let more or less light pass through the lens to the sensor or film. By adjusting the diaphragm, a photographer controls the aperture and therefore the depth of field of the resulting photo.

Diffused Light. A soft light that is filtered or scattered by something, causing it to be non-directional with more even illumination and softer shadows. Natural light from the sun may be diffused by clouds, for example. Artificial lighting can be diffused by directing the light through a modifier such as a softbox. This type of lighting is often preferred in portraits due to the more flattering look of softer shadows and facial features.

Diffuser. Any semi-translucent material that diffuses light, scattering the rays to create a softer quality. Typically placed between the light source and the subject, diffusers can be made of both hard and soft materials. They can also be both commercially produced or homemade with things found around the house or studio.

Digital Asset Management (DAM). Software that allows photographers to safely and efficiently store, organize, and share digital media files such as photos and videos. Photos can be tagged, grouped, filtered, and searched through. Some apps, such as Adobe Lightroom, provide both image editing features as well as digital asset management.

Digital Photography. The creation of photos using electronic photodetectors, typically silicon semiconductor image sensors, in a camera to capture light rays focused by a lens rather than photographic film or photosensitive chemicals. The captured images are typically digitized and stored on a memory card or onboard storage of the camera before it is viewed on a digital display, edited with software, and/or shared through the Internet. Digital cameras (and particularly smartphones) have revolutionized photography by making shooting and sharing photos fast, cheap, and ubiquitous.

Digital Single-lens Reflex (DSLR) Camera. A camera that combines a traditional single-lens reflex (SLR) design with a digital imaging sensor. In an SLR camera, light passing through the lens is directed upward into a prism and then through the viewfinder into the photographer’s eye. When the shutter button is pressed, the mirror flips out of the way, allowing the light to pass onto the shutter and sensor system for a photo to be exposed.

Distortion. When lines or objects in a photo appear curved or deformed in some way, usually as a result of the lens. Types of distortions include optical (e.g. barrel, pincushion, and mustache) and perspective.

Dots Per Inch (DPI). The resolution of a printed photo. Refers to how many printed dots are found within a line spanning one inch (2.54cm) of a print. The higher the density of dots, the higher the resolution of the image.

Dust Spots. Unwanted dark spots that show up in digital photos and are caused by dust particles on the imaging sensor. These spots are more likely to be visible when shooting a solid color scene (e.g. the sky) with a small aperture (i.e. a higher f-number). Some cameras have built-in sensor dust removal features, while other cameras will require photographers or repair technicians to manually blow or wipe the dust from the sensor.

Dynamic Range. The contrast ratio between the darkest and brightest tones in a photo or scene. The greater a camera’s dynamic range, the greater its ability to capture a scene with both dark shadows and brilliant highlights without clipping, or losing detail in those areas by rendering them as pure black or white, respectively.

E

Electronic Viewfinder (EVF). A type of camera viewfinder that uses a small electronic display to help photographers compose photos, adjust settings, and review images. While the downside is that photographers are not looking at the real world through viewfinder optics, the electronic viewfinder’s advantages over the optical viewfinder include real-time exposure previews and useful information overlays.

Enlarger. Also called a projection printer, this is a darkroom device that allows photographers to produce a photographic print that is larger in physical dimensions than the original film negative or transparency by projecting the image downward onto photo-sensitive paper below.

ETTL. Exposing to the left. Underexposing a photo so that the histogram is pushed toward the left in an effort to avoid clipped shadows. This technique was commonly used in film photography due to negative film having greater recovery potential in highlights than in shadows. With digital photography, however, there is more latitude in the shadows and photographers typically expose to the right (ETTR).

E-TTL. Evaluative though-the-lens. Automatic flash metering that fires a pre-flash, measures the resulting light that comes into the camera, and then uses that information to calculate the proper flash exposure time.

ETTR. Expose to the right. Overexposing a photo so that the histogram is pushed toward the right in an effort to avoid blown highlights. This technique is commonly used in digital photography due to the greater recovery potential in shadows than in highlights. With negative film, however, there is more latitude in the highlights and photographers typically expose to the left (ETTL).

EV. Exposure value. A number that represents an equivalent exposure based on a combination of shutter speed and aperture. Combinations that produce the same exposure of a scene will have the same EV. Each 1 EV change corresponds to a power-of-2 exposure step, or stop, so increasing by 1 EV doubles the exposure, and decreasing by 1 EV halves the exposure.

Exhibition. When photographs and other artworks are displayed in a public place such as a museum, art gallery, or photo club so that the public can view them in person. Exhibits are generally on display for a limited amount of time, after which they are replaced by new artworks, but there are also permanent exhibitions.

EXIF. Exchangeable Image File Format. Officially stylized as Exif (without all caps), this is the dominant metadata standard that specifies formats for information recorded when photos or other types of media are captured by a digital camera. Supported by virtually all camera manufacturers, metadata included in Exif include things like camera settings when a photo is captured (e.g. aperture, shutter speed, focal length, etc.), technical metrics of an image, date/time/location info, thumbnail previews, copyright details, and more.

Exposure. The amount of light per unit area recorded by photographic film or a digital image sensor as a result of the combination of aperture, shutter speed, and light in the scene. Different camera settings can have equivalent exposures. The term is also used generally to refer to a single open-and-close cycle of the shutter in the creation of a photograph, though more than one exposure can be combined to create a “multiple exposure” photo.

Exposure Bracketing The capturing of multiple photos of the same scene with the only difference being varying exposure settings. This can be used to ensure that one of the exposures is optimal, or the multiple exposures can be combined in post-processing to create a high dynamic range (HDR) photo since the images span a wider dynamic range than a single exposure can.

Exposure Compensation. A camera feature that allows photographers to override the exposure calculated by the built-in light meter by increasing or decreasing the exposure value (EV). Often used when the scene is dominated either by light tones (e.g. a snowy landscape) that can normally lead to underexposed photos or by dark tones (e.g. a close-up ninja portrait) that can normally result in overexposed photos.

Exposure Triangle. A visual representation of the relationship between shutter speed, aperture, and ISO in creating a photographic exposure.

Extension Tube. A lens add-on that increases the distance between the lens and the imaging plane (e.g. film or sensor) in the camera. Lacking any glass elements, the hollow tube reduces minimum focus distance and increases magnification, allowing non-macro lenses to be used for close-up macro photography.

F

Field of View (FOV). The portion of the world that is visible through and capturable by a camera. When expressed as an angle (of the view cone), this is also referred to as the angle of view (AOV). Field of view depends on the focal length of the lens and the size of the sensor/film.

Fill Light. A secondary light source in photography used to lighten shadows and reduce contrast in an image. It is typically placed on the opposite side of a subject from a main light.

Film. Often referred to as photographic film or camera film, this is a strip or sheet of a transparent material coated with a light-sensitive emulsion on one side. After being exposed to light through a camera lens, a latent image is recorded to the emulsion invisibly. This image can then be revealed by developing the film with specific chemicals that makes the latent image visible on the film and then fixes it in place by removing the light-sensitive nature of the film. This image, whether a negative or positive image and whether color or black-and-white, can then be printed onto a different medium, projected, or digitized, among other things.

Film Photography. The practice of creating photographs on light-sensitive film as the medium by which images are recorded. After the light-sensitive chemicals in the thin emulsion of film are exposed to light, a latent image is recorded to the film. This latent image is then turned into a visible image by developing/processing the film through a series of chemical baths. Film photography was the dominant medium for many years before the rise of digital photography.

Fisheye Lens. A type of ultra-wide-angle camera lens that produces a distorted, non-rectilinear convex image with a field of view that is typically somewhere between 100° and 280°. Objects close to the center of the frame will appear unnaturally large while things found at the edges of the frame are reduced in scale. The distortion is similar to what one sees when looking through a security peephole in a door.

Flag. An object or tool that blocks light in order to cast a shadow, create negative fill, or reduce/eliminate lens flare. Commonly black in color and rectangular in shape.

Flash. A device that creates a short burst of light to provide artificial illumination for a scene. The purpose can be to help a camera properly expose a low-light environment, create a custom lighting scenario, freeze a moving subject, or fill in harsh shadows when dealing with strong lighting. Flashes can be built directly into cameras or found as standalone devices, and they range in size from a tiny unit found on a compact camera to a sizable strobe found in a studio.

F-number. Also known as focal ratio, f-ratio, or f-stop, this is the number that specifies a lens’ aperture. It is the ratio of focal length to effective aperture diameter. A low f-number denotes a larger aperture size that allows more light to reach the camera’s film or sensor. Lenses generally feature a standard f-stop scale that follows the powers of the square root of two: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64, and so on. Each f-number in this sequence is one stop away from the ones before and after.

Focal Length. The distance, in millimeters, between the optical center of the camera lens and the sensor or film recording the image. A shorter focal length provides a wider field of view (i.e. wide angle) and lower magnification while a longer focal length leads to a narrower field of view (i.e. telephoto) and higher magnification.

Focus. The plane in three-dimensional space on objects will be rendered as sharp in a photograph. Adjusting focus of a lens moves this plane forward (toward the camera) and backward (away toward the background).

Focus Point. The point within the frame on which a camera’s autofocus feature attempts to bring into sharpest focus. A camera will attempt to make the plane of focus intersect the exact location in a scene or subject highlighted by the focus point.

Focal Plane Shutter (FPS). A type of shutter that sits right in front of a camera’s focal plane.

Focus Stacking. Capturing multiple digital photos at different focus distances and then combining them into a single image with a greater depth of field than is possible with a single exposure. This technique is commonly used in macro and landscape photography.

Forced Perspective. A creative technique in which objects or subjects in the frame are made to appear smaller, larger, closer, or farther than they are in real life. This is done by using careful positioning and framing to create an optical illusion with the space between subjects.

Foreground. The portion of a scene that is closest to the camera. This region often sets the stage for what is seen at further points in the middleground or background.

Four Thirds. A camera system standard originally created by Olympus and Eastman Kodak for the design of DSLR and mirrorless cameras. The Four Thirds sensor has an imaging area of 17.3x13mm, which has a diagonal of 21.63mm, or roughly half of the diagonal of a 35mm film negative. Multiple companies have joined the Four Thirds standard to create camera bodies and lenses that are all compatible with one another. While the Four Thirds standard was geared toward DSLRs, the subsequent Micro Four Thirds standard uses the same Four Thirds sensor but eliminates the mirror box and pentaprism for mirrorless cameras.

Frames Per Second (FPS). A camera’s maximum continuous shooting (burst) rate for still photos or available frame rates for video.

F-stop. Another term for f-number.

Full Frame (FF). The sensor size in digital photography based on the 35mm format that became dominant in film photography. A full-frame sensor measures 36×24mm, has an aspect ratio of 3:2, and has a diagonal measurement of roughly 43mm.

G

GAS. Gear acquisition syndrome. Often used to describe a photographer’s addiction to continually purchasing new camera equipment, often without any real practical need.

Geotagging. The adding of geographical location information to the metadata of a photo, typically in the form of latitude and longitude coordinates. Knowing the location where photos were captured can both add context when reviewing photos and also aid in the searching and organizing of images.

GIF. Graphics Interchange Format. A bitmap image format introduced in 1987 that supports 8 bits per pixel, meaning each image can display a maximum of 256 different colors. GIFs are ubiquitous on the Web due to the format being widely supported, but the color limitations make the format less suitable for photos than formats such as JPEG. However, photos are widely shared in GIFs in the form of online memes.

Gigapixel (GP). One billion pixels. A term used to refer to the resolution of a photos, displays, and camera sensors.

Glass. A slang term used by photographers to refer to a camera lens. e.g. “Instead of investing in the best camera, get some good glass.”

Gobo. Stands for “go before optics” and refers to any object placed between a light source and a subject to shape light and/or alter shadows.

Golden Hour. Also referred to as magic hour, is the period of time immediately after sunrise and immediately before sunset when the sun is low enough in the sky to cast a soft, warm light. This window of opportunity is prized by photographers, especially portrait shooters, for its quality of natural light.

GPS. Global Positioning System. A satellite-based radio navigation system that is owned by the United States and operated by the US Space Force. It is one of the leading systems used by camera manufacturers for geotagging digital photos, or embedding location information into the file’s metadata.

Graduated Neutral Density Filter (GND) A kind of neutral density filter in which the amount of light blocked is a gradient from one side to the other. Useful for scenes like landscapes where photographers need to reduce the contrast between a bright sky and a dark landscape.

Grain. Also known as film grain, this is the visible silver crystals in a film’s emulsion that can be seen in resulting prints as well. Various films have different levels of grain size and quality, and this is an important consideration for film photographers picking a photographic film to use for their work.

Gray Card. A gray-colored card used by photographers as a reference point for capturing consistent exposure and/or color across multiple photos. The card is typically 18% neutral gray, meaning it has 18% reflectance across the visible spectrum. This value represents the mid-point between pure black and pure white on a logarithmic or exponential curve.

Guide Number (GN). A number used to indicate the power of an electronic flash and used to calculate the necessary f-stop for any flash-to-subject distance (or the distance for a given f-stop). Guide number = f-number x distance. The larger the guide number, the greater the distance the flash can properly expose a subject.

H

Hard Light. Light that causes harsh shadows. This quality of light causes the lines between highlights and shadows are immediate and well-defined. Hard light can be created by using a single, bright light source that is small in area relative to the subject. The smaller the light source, the more abrupt the transition between light and shadow in the scene.

High Dynamic Range (HDR) A type of photography that aims to reproduce a greater range of luminosity than what is ordinarily captured with standard photographic equipment and techniques. This is often done by capturing multiple photographs at different exposures and then combining them into one photo with a higher maximum and lower minimum tonal value.

High-Key Lighting. A lighting style that aims to achieve a low lighting ratio in a scene. The result typically features brightly-lit scenes and subjects, a higher degree of fill lighting, soft lighting, soft/minimal shadows, and low contrast. This lighting style provides a mood that is optimistic, positive, light, airy, cheerful, upbeat, and/or hopeful.

High-Speed Sync (HSS). A flash feature that allows you to synchronize your flash output when using shutter speeds faster than the camera’s native flash sync speed. This is achieved by rapidly firing the flash multiple times during the exposure, effectively extending the duration of the flash output and allowing the use of wider apertures or faster shutter speeds in bright lighting conditions. High-speed sync can be useful for reducing motion blur, controlling depth of field, or balancing flash and ambient light levels in challenging lighting scenarios (e.g. adding fill-flash to a model outdoors on a bright day).

Highlights. The lightest areas in a photograph. One of the main components of an image’s dynamic range, along with midtones and shadows. When a photo is overexposed or when a camera is not able to capture enough dynamic range, detail may be lost in the highlight areas of the photo (something known as clipped or blown highlights). Represents the roughly 25% of the brightest pixels in a photo.

Histogram. A graph that represents the distribution of tonal values in a photo. From left to right, the graph shows the relative number of pixels in the image that are pure black, shadow, midtones, highlights, and pure white. Histograms provide photographers with an at-a-glance look at how a photograph is exposed and whether there is any clipping or under/over-exposure.

Hot Shoe. An accessory connector slot that is typically found on top of a camera for attaching things such as flashes, lights, microphones, wireless triggers, external viewfinders, GPS receivers, light meters, and more. Unlike a cold shoe, a hot shoe is “hot” because it is capable of transmitting electronic signals to the mounted device.

Hybrid Camera. A camera designed to excel at shooting both still photographs as well as video. The form factor is usually that of a still camera, but the video recording capabilities can be more in line with larger cinema-oriented cameras.

Hyperfocal Distance. A focus distance beyond which all objects in a scene are rendered with “acceptable” focus, resulting in the maximum depth of field at a given aperture.

Hyperlapse. A moving time-lapse in which the viewer is transported through both space and time. Unlike a traditional timelapse, in which the camera shoots photos over time from roughly the same spot, a hyperlapse is created by moving the camera a short distance between each shot and over a long distance during a sequence of images.

I

IBIS. In-body image stabilization. A mechanism found in digital cameras that compensates for camera movement while an exposure is being made by moving the image sensor at the final point of the optical path. These systems compensate for up to 5 axes of movement: X, Y, Roll, Yaw, and Pitch. While optical image stabilization (OIS) is built into individual lenses, IBIS in a camera works with all lenses that can be mounted to it.

Image Quality (IQ). The ability of a camera, lens, or film to properly capture images that are desirable to photographers and human viewers. This is typically a true-to-life rendering of a scene as close as possible to what the human eye sees (and what the brain interprets). Attributes of a photo that contribute to the visual characteristic of image quality include sharpness, contrast, color accuracy, distortion, optical aberrations, noise/grain, and more.

Image Sensor. An electronic device, usually a silicon semiconductor circuit, that captures incident light information in the form of photons, converts them to electronic signals, and transmits the data to an image processor to create a digital photograph. The two leading technologies used in digital cameras are the charge-coupled device (CCD) and the complementary MOS (CMOS), with the majority of sensors in modern photographic cameras being CMOS. The millions of light receptors on a sensor are called photosites, and the number of photosites is typically conveyed in megapixels. In photography’s evolution from film to digital, image sensors replaced light-sensitive films as the way light is captured through a camera lens.

Image Stabilization (IS). A feature that compensates for camera motion during image exposure in order to reduce blur, particularly at slower shutter speeds. This can be both mechanical and electronic, and it can be found in both lenses and cameras.

Intentional Camera Movement (ICM). A type of photography in which the camera is moved or lens adjusted during an exposure for creative effect. These acts produce blurring in resulting photos, whether from the movement of the camera or from adjusting the focus or zoom of the lens.

Interchangeable Lens Camera (ILC). A camera that accepts interchangeable lenses rather than having a fixed non-removable lens.

Internal Focusing. A design for camera lenses in which focus is achieved by only moving internal lens elements without any rotation or shifting of the front lens element. Advantages include the ability to more easily use certain filters (screwed-in polarizing) and hoods (petal), keeping dust out, not hitting macro subjects, avoiding “zoom creep,” and smaller lens designs.

Intervalometer. Also known as an interval meter or an interval timer, this is a (usually small) device that connects to a camera and repeatedly triggers exposures at a consistent interval over a period of time. They are commonly used to create timelapses (capturing a large number of photos of a scene over a long period of time and then combining them as frames of a passage-of-time video) as well as astrophotographs (capturing a set of night sky photos over a period of time and then blending them together into a single image).

IPTC. International Press Telecommunications Council. A London-based consortium of over 50 major news companies and organizations from around the world. As the global standards body of news media, the IPTC defined a standard for photo metadata that is the world’s most widely accepted and used.

ISO. International Organization for Standardization. A standard for measuring a camera film or sensor’s sensitivity to light. For film, this refers to how quickly the chemicals react to light, and for digital sensors, this refers to the gain (or amplification) applied to the signal before the image is recorded.

J

JPEG. Joint Photographic Experts Group. Also abbreviated JPG, this is a lossy compression standard named after the group that created it in 1992. It has since become the most widely used compression method in the world for digital photos. The fact that it’s lossy means that editing and resaving the files causes a loss in image quality each time.

Juxtaposition. A compositional concept in which two or more objects or subjects in a photo have strong and interesting contrast between them, including in lighting, color, shape, texture, subject matter, and more. This contrast can be both eye-catching and thought-provoking, causing the viewer to think or feel something that the photographer is trying to convey.

K

Kelvin (K). The international base unit of absolute temperature that’s used to conveniently express color temperature in photography. Higher temperatures (e.g. over 5000 K) are cooler, bluer colors, while lower temperatures (e.g. under 3000 K) are warmer, yellower colors. “Daylight” is traditionally around 5600 K.

Key Light. The primary source of artificial lighting that a photographer uses to light a subject and/or scene. It is typically the most important light in a scene and the first that is established in a lighting setup. The intensity, angle, and color of the key light have a primary impact on the look and mood of the resulting light.

Kicker Light. A secondary accent light in a lighting setup that helps define the edges of your subject by highlighting them against the background. Usually placed at an angle behind the subject, this light’s name comes from the fact that it gives some extra “kick” to the portrait. Also known as a rim light.

L

Landscape Orientation. A photo that is wider than it is tall. When held vertically, cameras generally capture images in landscape orientation due to the horizontal orientation of the rectangular image sensor within. Landscape orientation images can often be displayed larger on standard computer and laptop displays since those screens usually also have the same orientation.

Landscape Photography. A genre in which photographers aim to capture the beauty of the natural outdoor world. While they may contain humans and animals within the frame, most landscape photos do not as they typically focus only on plants, weather, land, water, and sky in a scene.

Large Format. Photography done with an imaging surface of 4×5 inches (10.2×12.7cm) or larger. Large format is considered to be anything larger than medium format, which is in turn defined as being anything smaller than large format but larger than the classic 35mm full-frame format 24x36mm (0.94×1.42in). Cameras in the early days of photography were typically large format before the development of new technologies introduced smaller and smaller films (and subsequently sensors). Sizes seen in large format cameras throughout history have included the most common 4x5in, the quarter-plate (3.25×4.25in/8.3×10.8 cm), 5x7in (12.7×17.8), and 8×10in (20×25 cm).

LCD. Liquid crystal display. The display technology that’s ubiquitous in camera screens, viewfinders, computer monitors, and more. It uses liquid crystals, polarizers, and backlighting to produce the displayed images.

LED. Light-emitting diode. A semiconductor light source technology that has applications in photography ranging from lighting to displays. As a light source, they are flexible (with a wide range of colors and intensities), energy-efficient, low heat, and long-lasting. In a display, they are bright, energy-efficient, sharp, flicker-free, and long-lasting.

Lens. An optical body mounted to a camera and used to focus light onto a sensor, film, or light-sensitive medium in order to capture an image through chemical or electronic processes. One of the main components of any camera system, and may be both permanently attached to a camera or removable as an interchangeable lens. May include a single lens element or a combination of carefully-arranged lens elements. Typically created with glass, lenses can also be made from plastic and other transparent and semi-transparent materials.

Lens Flare. An optical phenomenon that occurs when light that does not contribute to forming an image enters a lens and is scattered within the elements. The artifacts created in the resulting photo are often undesirable and can be reduced or eliminated by repositioning the lens and/or using something (e.g. a lens hood) to block the incoming light, though photographers may also intentionally aim to have flare in photos for artistic effect.

Lens Hood. Also known as a lens shade, this is a device attached to the front of a camera lens that is designed to block direct light from entering and causing lens flare and glare. A secondary purpose for using a lens hood is to protect the front element of the lens from getting damaged or dirty. Hoods are traditionally made of plastic or metal, though do-it-yourself hoods can be fashioned from things like paper and cardboard as well. Hoods are sometimes bundled with lenses, especially high-end ones, but they can also be purchased as optional accessories.

Lens Mount. The interface between a camera lens and camera body, allowing interchangeable lenses to be securely mounted to the camera at exactly the right distance from the focal plane. Mounts can be purely mechanical for manual lenses or they can also feature electrical connectivity for autofocusing lenses. Camera manufacturers typically use proprietary mounts exclusive to their own cameras, but there are also standardized mounts (e.g. Micro Four Thirds) used across cameras from multiple brands.

Light Meter. A device that measures the amount of light for the purpose of calculating the proper exposure for a photo. Reflected-light meters (such as those in most cameras) measure light reflected by the subject or scene, while incident-light meters directly measure the amount of light falling on the subject. Once the light is measured, a light meter will provide the photographer with the calculated shutter speed and f-number for optimal exposure given the ISO.

Light Painting. A technique in which a photograph is created with a moving light source in the frame during a long exposure. The movement of the light is rendered as trails in the resulting image, giving photographers the ability to “paint” with one or more lights (often of different colors) over the course of an exposure. This requires the skill of being able to visualize the art in 3-dimensional space as it’s being drawn, as typically the artist cannot see what they are painting until the exposure is completed. In light painting, lights are the brushes and the frame is the canvas.

Lighting Ratio. The comparison of the main light illuminating a subject (the key light) and the secondary light filling in the shadow areas (the fill light). The higher the lighting ratio, the higher the contrast, and the lower the lighting ratio, the lower the contrast. A good rule of thumb is a lighting ratio between 2:1 and 4:1 for portrait photography. A ratio of 1:1 has a flat, one-dimensional look while a ratio of 8:1 has a dramatic look with dark shadows.

Long Exposure. The use of a slow shutter speed for a longer-duration exposure to capture an extended period of time. This can be for necessity, such as when shooting in low-light environments and needing increased exposure time to achieve proper exposure. Another reason to do long exposure photography is for creative effect, as moving elements within the frame may be rendered as blurry or possibly eliminated altogether. Moving points of light (e.g. stars) may be rendered as light trails, and water will be captured as smooth flows.

Loop Lighting. A common lighting setup in portraiture in which the main light is placed slightly above and to one side of the subject, creating a circular, “loop”-shaped shadow on the other side of their face. The shadow is usually found below and to the side of the nose in a loop, or “C”, shape around the subject’s cheek and nose. This type of lighting style produces flattering portraits in which there is depth and dimension in the subject’s face.

Low-Key Lighting. A lighting style that aims to achieve a high lighting ratio in a scene. The result typically features dimly-lit scenes and subjects, an emphasis on shadows, dark tones, hard lighting, and high contrast. This lighting style provides a mood that is serious, mysterious, dramatic, somber, and/or emotional.

Low-Pass Filter. Also known as an optical low-pass filter (OLPF), anti-aliasing, or blur filter, this sits over a digital imaging sensor that allows lower frequencies of light to pass through to capture coarser details while blocking higher frequencies of light with super fine detail. By introducing a slight blur in this way, the filter helps to prevent moiré interference patterns and other aliasing artifacts. Some cameras eschew having a low-pass filter in favor of sharper images at the expense of moiré.

Luminosity. The perceived brightness of an object. Photo editing apps such as Adobe Lightroom feature luminosity masks that allow photographers to make selections based on the luminosity of pixels in an image, from highlights to midtones to shadows.

M

Macro Lens. A lens capable of reproduction ratios of at least 1:1 that can be used to capture close-up photos of small subjects in the field, something known as macro photography. While macro lenses are designed for close-up photography, they can also be used for standard pictures in genres such as portraiture and landscapes.

Macro Photography. Photography that produces photos of small-scale things at larger-than-life sizes. By capturing close-up images of tiny subjects, photographers can give viewers a view of the world that may not be visible to the naked eye.

Magic Hour. Another name for golden hour, or the first hour after sunrise or the last hour before sunset in which the soft, warm sunlight is prized by natural light photographers.

Manual Focus (MF). A process in which a photographer (rather than the camera) adjusts the lens’ focus to achieve the desired sharpness in a photo.

Manual Mode. A camera mode in which the photographer chooses the desired exposure by manually selecting shutter speed and aperture (and optionally ISO).

Medium Format (MF). A film or digital sensor size that’s larger than 35mm full-frame (24mmx36mm) but smaller than large-format (4inx5in). The most common medium format film type is 120, which is roughly 6cm wide — cameras can capture a variety of frame sizes on this film format with a range of aspect ratios, including 6×4.5cm, 6×6cm, 6×7cm, 6×9cm, and the panoramic 6×17cm.

Megapixel (MP). One million pixels. A unit of measurement of the resolution of a digital photo, camera, display, scanner, and more. The megapixel count of an image, sensor, or display is calculated by multiplying the width and height of the pixels, photo sites, or display elements, respectively.

Memory Card. An electronic data storage device used for storing digital information, particularly photos and videos captured by digital cameras. Typically using non-volatile flash memory, the most popular memory card format in the world is the SD (Secure Digital) family of card formats. Other popular formats seen in the industry include CF (CompactFlash), XQD, and CFexpress. In addition to a wide range of types and form factors, memory cards are available in different brands, capacities, and classes (which refers to the read/write speeds).

Memory Card Reader. A device for accessing the data stored on a memory card. Rather than directly connect a camera to a computer, photographers often use a USB memory card reader to transfer photo and video data onto a computer. Data can also be written to a memory card using a reader. Memory card readers often have multiple slots for compatibility with different memory card formats.

Metadata. Information stored in a digital photo file that is not typically visible when viewing the photo but can be accessed with certain software to reveal the photo’s technical details, copyright info, and more. One of the most common metadata standards in digital photography is EXIF data, which includes info on camera settings, time/date, and location.

Metering. When the camera evaluates the amount of reflected light in a scene in order to determine the correct shutter speed and aperture for an optimal exposure at the current ISO speed.

Metering Mode. The way in which a camera calculates optimal exposure through metering the light in a scene. Common modes include spot (only a small area in the center of the scene is analyzed), average (the average of the entire scene), center-weighted average (the central 60-80% of a scene is analyzed), or multi-zone metering (several areas are analyzed and combined). Different modes are useful for different lighting scenarios, though for highly complex lighting environments a photographer may choose to forgo camera metering altogether and shoot in manual mode.

Micro Four Thirds (MFT or M4/3). A mirrorless interchangeable lens digital camera system standard launched by Olympus and Panasonic in 2008 and joined by a large number of camera manufacturers. The specification uses the Four Thirds sensor size while omitting a mirror box and pentaprism to allow for smaller cameras and lenses.

Midtones. The areas of a photo that are neither highlights nor shadows but have luminance values that are roughly in the middle 50% of the image’s tonal range (in other words, the middle tones). One of the main components of a photo’s dynamic range.

Minimum Focus Distance. The shortest distance from a subject at which a camera lens can achieve focus. This distance is measured from the subject to the focal plane mark on the camera body rather than to the front of the camera lens (which is called the working distance).

Minimum Working Distance. The shortest distance between a subject and the front of the lens for which the lens can achieve focus. This informs the photographer on how much room they have to work with, particularly in macro photography when getting up close to tiny subjects. A larger working distance gives the photographer more flexibility for composition and lighting.

Mirror Lockup. A feature in single-lens reflex (SLR) cameras that allows the photographer to flip the mirror up and lock it in that position in advance of the shutter being triggered. This reduces camera vibration during the capture of a photo (thereby reducing blur) and also allows the mounting of lenses that extend further into the camera’s mirror box.

Mirrorless Camera. A type of digital camera with interchangeable lenses that does not contain a mirror and pentaprism for an optical viewfinder system like digital single-lens reflex cameras (DSLRs), but instead has an electronic viewfinder with the live view of the scene.

Mode Dial. A dial found on digital cameras that allows the photographer to change between different camera modes, which may include manual modes (e.g. program, aperture priority, shutter priority, manual) and/or automatic scene modes (e.g. action/sport, landscape, portrait, night, macro).

Moiré. An effect that occurs when repetitive lines or patterns cause an interference pattern to occur. In cameras, this undesirable interference pattern can be captured in photos when the detail of the repetition exceeds the resolution of the imaging sensor. To combat this, camera manufacturers commonly added optical low-pass filters (OLPF) over their sensors, though higher-resolution cameras may forego the filter for increased sharpness.

Monopod. A camera support that has only a single leg, compared to the three legs found on a tripod. ‘Mono’ is a prefix that means “one, only, single.” While monopods are not as stable as tripods and cannot support a camera independently unless staked or fixed into the ground somehow, they are usually collapsible and lightweight and therefore a convenient and portable way to provide a camera with extra stabilization while on the go.

MTF. Modulation transfer function. A technical way to measure a lens’ optical performance potential. An MTF chart plots the contrast and resolution of a particular lens, with the x-axis representing the distance from the center of the frame (center at left and edge at right) and the y-axis representing light transmission (0% at bottom and 100% at top). MTF charts generally plot sagittal and meridional lines for the contrast measurements of lines that run parallel or perpendicular (respectively) to the line from the center to the edge of the frame.

Multiple Exposure. Two or more frames superimposed in a single photograph. These can be created both in camera (e.g. exposing a single frame of film multiple times) or digitally (e.g. using software to stack multiple images into a single frame).

N

Natural Light. Light that is from the Sun, Moon, or another natural source (e.g. fire, bioluminescence, lava) rather than from a camera flash or other artificial light source. Natural light photography involves only using this ambient lighting to expose a photo. Since natural light changes over the course of a day, picking the right time for a photo shoot to take advantage of sunlight angle and quality becomes an important factor in a photo shoot. One of the most prized periods of the day for natural light is golden hour.

Nature Photography. Photography done outdoors that focuses on natural elements such as landscapes, plants, wildlife, weather, natural phenomena, and more. Photos can range from wide-angle views that capture sweeping scenes to close-up macro photos showing details of the world that are ordinarily hidden from the naked eye.

Negative. A photographic image, usually on film, in which the shade and/or color values are reversed from the true image — the lightest parts of the image are darkest on the negative, and the darkest parts are lightest. With color negative film, colors are inverted into their respective complementary colors. A positive print or scan can be made from a negative by inverting it, whether in a darkroom through the enlarging process or with digital software.

Negative Space. Also known as “white space” or “empty space,” this is the space surrounding a subject or object. While it is not usually a primary point of focus, it can help create “breathing room” in an image, provide balance, add visual appeal, and/or direct a viewer’s eyes to the main subject.

Neutral Density Filter (ND). A type of filter that reduces the amount of light entering the camera, modifying the intensity of all wavelengths equally so that there are (ideally) no changes in color. Allows photographers to use exposure settings that would otherwise result in overexposed photos (e.g. for a longer exposure or larger aperture on a bright sunny day).

Nifty Fifty. A nickname for a 50mm prime lens, which is a type of lens that is fixed to a single focal length, rather than being able to zoom in and out. These lenses are often referred to as “nifty fifty” because they are relatively inexpensive and offer a lot of versatility for photographers.

Noise. The unwanted grainy or speckled texture that can appear in an image, particularly in darker areas or in images that are shot at high ISO values. Noise can be caused by a variety of factors, including the image sensor in the camera, the quality of the image processing software, and even the ambient temperature.

Noise Reduction. Digital processing to remove noise from a photograph, whether done in-camera by firmware or by a feature/tool in an image processing/editing application.

Normal Lens. A lens that has a focal length approximately equal to the diagonal size of the film or image sensor it is used with. For example, on a 35mm film camera or full-frame digital camera, a normal lens has a focal length of around 50mm. Normal lenses are called “normal” because they provide a field of view and perspective that is similar to what the human eye sees. They are often used for general-purpose photography.

O

Optical Viewfinder (OVF). Allows the photographer to compose (and usually focus) a scene while looking at the scene itself rather than an electronic display (as with an EVF). This can be a through-the-lens viewfinder (like in SLRs) or a look-through viewfinder (like in rangefinders).

Overexposure. A condition where too much light is allowed to reach the film or image sensor, resulting in a washed-out or overly bright image. Overexposure can be caused by a variety of factors, including using a lens with a wide aperture, using a high ISO setting, or using a slow shutter speed in bright lighting conditions.

P

Panning. A technique used to create a sense of motion in a photograph by following a moving subject with the camera and taking a photograph with a slower shutter speed. The result is a photograph where the subject is in focus and appears sharp, while the background is blurred and appears to be moving, giving the impression of motion. To achieve this effect, the photographer needs to follow the subject with the camera as it moves, keeping it in the same position in the frame.

Panorama. A wide-angle view or representation of a physical space, whether in image form or as a series of images. It is typically created by stitching together multiple photographs taken from a single vantage point, or by using specialized panoramic cameras or lenses that allow for the capture of wide fields of view.

Phase Detection Autofocus (PDAF). A camera autofocus system that divides incoming light from opposite sides of the lens into two images and compares them to calculate whether the subject is front- or back-focused. This information is then used to adjust the lens until focus is achieved.

Photo Walk. An event or activity in which photographers go for a walk as a group with the purpose of taking photographs. Photo walks can take place in a variety of locations, such as city streets, nature trails, or other outdoor spaces, and the goal is often to explore a new area and find interesting subjects to photograph.

Photogram. A photograph made without a camera by placing objects directly onto light-sensitive paper or film and exposing it to light. The resulting image is a silhouette of the objects, with the areas around the objects remaining white or light-colored.

Photograph. An image created by capturing light with a camera, usually via a digital sensor or film, and recording it onto a storage medium. The process of creating a photograph typically involves aiming the camera at a scene or subject and pressing the shutter button to take the picture. The resulting image is a representation of the scene or subject as it appeared at the time the photograph was taken. Photographs can be taken with a variety of cameras, including digital cameras, film cameras, and smartphones, and can be produced in a variety of sizes and formats. They can be used for a wide range of purposes, including documenting events, capturing memories, telling stories, expressing emotions, and creating works of art.

Photographer. A person who takes photographs, either as a hobby or as a profession. Photographers use cameras to capture images of people, places, and things in a variety of settings, including studios, outdoors, or on location at events or assignments. Professional photographers may specialize in a particular type of photography, such as portrait, wedding, fashion, commercial, or fine art photography. They may also work in various industries, such as journalism, advertising, or the arts. Some photographers are self-employed and work on a freelance basis, while others may be employed by companies or organizations.

Photography. The art or practice of creating still or moving images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as film. Photography has a long history dating back to the early 19th century and has evolved significantly over time with the development of new technologies and techniques. There are many different types of photography, including portrait, landscape, still life, documentary, and fine art, among others. Photographers may work in a variety of settings, including studios, outdoors, or on location at events or assignments. They may use a variety of cameras and other equipment to capture images, and may also use software to edit and manipulate their photographs.

Pinhole Camera. A simple camera that is made by creating a small hole in one side of a light-tight box. Light passes through the hole and is projected onto the opposite side of the box, creating an inverted image. Pinhole cameras do not have a lens, and they rely on the pinhole aperture to focus the light.

Pixel. Short for “picture element.” A single point in a digital image. Pixels are the smallest unit of an image that can be displayed on a digital screen, and they are what make up the total resolution of an image. Digital images are made up of a grid of pixels, with each pixel representing a specific color and brightness value. The more pixels that an image has, the higher the resolution of the image and the more detail it can contain.

Pixel Peeping. The act of examining the pixels of an image at a very high magnification, typically 100% or more, in order to evaluate the image’s sharpness and other image quality characteristics. Pixel peeping is often done by photographers who are looking for flaws or imperfections in their images, and who want to ensure that the images are as sharp and detailed as possible.

Point-and-Shoot Camera. A type of compact camera that is designed for ease of use and convenience. It is characterized by its small size, simple controls, and automatic features, which allow the user to take photographs by simply pointing the camera at the desired subject and pressing the shutter button. Features typically include a fixed lens and a built-in flash.

Polarizing Filter. A camera lens accessory that is used to reduce reflections and glare in photographs. It does this by polarizing the light that enters the camera, which can make the sky appear more blue and the clouds more white. Polarizing filters are often used in landscape photography to make the colors in the scene more vibrant and to reduce the amount of reflections in water and other reflective surfaces. They can also be used to reduce reflections on glass and other shiny surfaces in architectural and product photography.

Portfolio. A collection of photographs that a photographer has taken and selected as representative of their work. Portfolios are often used by photographers to showcase their skills and style, and to demonstrate their ability to produce high-quality images. Photographers may create portfolios for a variety of purposes, such as attracting new clients, applying for jobs or grants, or entering photography contests.

Portrait. A photograph that focuses on the face or head of a person or animal. Portraits are usually taken from the front or the side and are typically intended to capture the subject’s personality, expression, and appearance.

Portrait Mode. A feature found on some cameras and smartphones that is designed to take high-quality portrait photographs. Portrait mode uses a combination of hardware and software to create a shallow depth of field in the image, which is a technique used to blur the background of the image and make the subject stand out.

Portrait Orientation. The orientation of the camera when taking a photograph. When the camera is held vertically and the photograph is taken with the height of the image being longer than the width, the photograph is said to be in portrait orientation.

Post-Processing. Also referred to as “post,” this is the process of editing original camera data with software programs (e.g. Photoshop and Lightroom) to create an improved and/or customized final photograph. This can involve both basic edits (e.g. brightness, contrast, white balance, saturation, cropping) as well as more involved editing (e.g. cloning, compositing, masking).

PPI. Pixels per inch. A way to measure the resolution of a digital display. Refers to the number of pixels that are found in the space of one linear (not square) inch.

Prime Lens. A lens that has a fixed focal length, meaning that it cannot zoom in or out. Prime lenses are typically smaller, lighter, and faster than zoom lenses, as they have fewer moving parts and a simpler design. They are also generally more optically efficient and can produce sharper, higher-quality images than zoom lenses.

Print. A physical copy of a photograph that is created by printing the image onto paper or another material using an inkjet or other printing process. Prints can be made in a variety of sizes and on a variety of materials, including glossy or matte paper, canvas, metal, or acrylic.

Product Photography. The art of capturing visually appealing and enticing images of items or merchandise, typically for advertising, e-commerce, or promotional purposes. It aims to highlight the product’s features, quality, and aesthetics through careful composition, lighting, and styling, while maintaining accuracy and appealing to the target audience.

Program (P). A semi-automatic shooting mode that allows the photographer to control some aspects of the exposure, while the camera takes care of the rest. When a camera is set to program mode, the photographer can adjust settings such as ISO, white balance, and focus mode, but the camera determines the appropriate aperture and shutter speed for the scene.

Q

R

RAW. An image file is one that contains minimally processed data straight from a digital camera sensor (or scanner). These files are generally processed in raw editing software before being converted into a format such as JPEG or TIFF for printing or sharing online. Many camera manufacturers use proprietary raw file formats in their camera ecosystems, while others use open formats such as Adobe’s DNG. Not an acronym but is widely capitalized as though it were, including by companies like Canon.

Rear-Curtain Sync. A camera flash setting in which a flash is fired just before the camera’s shutter closes, rather than at the beginning of the exposure as it is in normal (front-curtain) sync. This can be useful in a variety of situations, such as when the photographer wants to capture a moving subject at the end of their movement with the background showing the subject’s motion as a blur leading up to the frozen moment.

Red Eye. A common problem in photography in which a subject’s eyes appear red in the image. Red eye is caused by the reflection of the camera’s flash off the blood vessels at the back of the subject’s eyes.

Reflector. A device that is used to reflect light onto a subject. Reflectors are often used to add fill light to a scene or to highlight certain features of the subject. They are especially useful in outdoor photography, where the available light may be harsh or uneven. They come in a variety of shapes and sizes, and they can be made from a variety of materials, such as foam board, paper, or metal. Reflectors can be either reflective or diffusive, and they can be white, silver, gold, or other colors.

Rembrandt Lighting. A type of lighting pattern named after the Dutch painter Rembrandt, who often used this lighting style in his portraiture. It is characterized by a small triangle of light on the subject’s cheek, opposite the light source, and it is often used in portraiture to create a sense of depth and dimension in the subject’s face.

Reproduction Ratio. The size of the image of a subject on the camera’s image sensor in relation to the actual size of the subject. Typically expressed as a ratio or fraction — for example, a reproduction ratio of 1:2 means that the image on the sensor is half the size of the actual subject. This is an important consideration in macro photography, as it determines how much the subject will be magnified in the final image. A higher reproduction ratio will result in a larger, more detailed image of the subject.

Resolution. The level of detail and clarity that is captured in an image. Resolution is typically measured in pixels, with a higher pixel count indicating a higher resolution and a greater level of detail. Resolution is an important factor in digital photography, as it determines the quality and print size of the final image.

RGB. Red, green, and blue. An additive color model in which the primary colors of red, green, and blue are added together in various proportions to create a wide range of possible colors. As an additive model, red, green, and blue are added to black, and the full combination of colors is white. Digital cameras and computer/phone displays typically work in RGB.

Rim Light. A light in a lighting setup that is placed behind the subject to create an outline (or edge or rim) of light, defining the subject by separating it from the background. The result can be a dramatic or mysterious look. Also known as an edge or kicker light.

Rule of Thirds. A basic composition guideline that suggests that an image can be divided into nine equal parts by two equally-spaced horizontal lines and two equally-spaced vertical lines. The theory is that if you place points of interest along these lines, or at the intersections of them, your photo will be more balanced and will have more visual interest.

S

Saturation. A term used to describe the intensity or purity of a color. In photography, it refers to the richness or vibrancy of the colors in an image. An image with high saturation has vivid, bright colors, while an image with low saturation has more muted, subdued colors.

Scene Modes. Preset settings on a camera that are optimized for specific types of scenes or subjects. They are designed to help beginner photographers get the best possible photo in a variety of different shooting situations by automatically adjusting the camera’s settings to suit the scene.

Scrim. A material placed between a light source and subject that softens or diffuses the light, reducing the intensity and/or harshness.

SD. Secure Digital. A memory card format that is commonly used by digital cameras. Introduced in August 1999 by SanDisk, Panasonic, and Toshiba, it uses flash memory technology to store large amounts of data on relatively small devices. Its primary competitor is the CompactFlash (CF) card.

SD Association (SDA). The non-profit organization formed in January 2000 by SanDisk, Panasonic, and Toshiba to manage SD Card standards. Around 1,000 companies are now a part of SDA.

Secret Photography. The practice of taking photographs without the knowledge or consent of the subjects being photographed. This can be done for a variety of reasons, such as to capture candid moments, to document events or situations, or for artistic expression. It can also be used to invade the privacy of others, and in some cases, it may be illegal or unethical.

Selfie. A self-portrait photograph, typically taken with a smartphone or camera held at arm’s length or with a selfie stick. Selfies are usually taken to be shared on social media or other forms of communication with friends or followers.

Self Portrait. A photograph that the photographer has taken of themselves. It is a way for the photographer to capture their own image and express themselves through the medium of photography.

Shadows. The darkest part of an image on the opposite side of the histogram from highlights, where relatively little light has hit compared to other parts of the frame. These areas help to provide depth, contrast, mood, and/or mystery to a photo.

Sharpness. The clarity of details in a photo. While various factors contribute to a photograph’s sharpness, primary ones include the imaging quality of a lens and the camera settings that were used when exposing the photo. Sharpness can also be adjusted on an existing photo using image editing software.

Shutter Lag. The delay that occurs between triggering the shutter of a camera and when the exposure is actually recorded. Components of this delay may include the time it takes to focus, calculate exposure, physically move the shutter mechanism, and recording the data to the memory card.

Shutter Priority. Also abbreviated on some mode dials as Tv, for time value, this is a camera setting in which the photographer chooses a fixed shutter speed while allowing the camera to adjust the aperture value (and possibly ISO) to achieve a proper exposure (as determined by the camera’s internal light meter).

Shutter-Release Button. Also known as a “shutter release” or a “release button,” this is the button or mechanism that is pressed or activated to cause the shutter to open and expose a photo. The shutter closes again according to the shutter speed chosen by the photographer or camera, or it may be held open indefinitely as long as the shutter-release button is depressed if the camera is set to Bulb mode.

Shutter Speed. Also known as exposure time, this is the time, in seconds, that the sensor or film inside a camera is exposed to light in order to capture a photograph. A fast shutter speed will freeze motion while a slow shutter speed will cause moving subjects in the frame to blur.

Single-Lens Reflex (SLR). A camera (most often referring to a film one these days) that uses a mirror to direct light between the viewfinder prism (for seeing and composing the scene) and the image sensor (when the shutter is activated to expose a photo).

Softbox. A light modifier consisting of a light source within a reflective closed chamber covered with a white, translucent material that diffuses the light, making it softer and minimizing harsh shadows. Available in a variety of shapes and sizes, softboxes are commonly used in portraiture and product photography.

Soft Light. Diffused light that does not cast hard, harsh shadows on a subject, with gradual transitions between bright and dark areas. This type of lighting typically comes from light sources that are both large and close.

Spot Metering. A metering mode by which a camera (or light meter) measures the light only in a very small area, typically 1-5% of the frame. This allows the photographer to take a light reading from a specific part of the scene and use that information to set the exposure for the entire photograph.

Spray and Pray. A term used in photography to describe when a photographer rapidly takes multiple photos in quick succession, with the hope that at least one of the shots will be a “keeper,” rather than taking time to carefully compose and time each shot. While this technique can be helpful in certain types of fast-paced and/or unpredictable photography, such as sports or wildlife, it is often looked down upon as being “amateur.”

Straight Out of Camera (SOOC). Photos as they were captured by the camera without any additional post-processing afterward prior to it being displayed.

Stop. A unit used to describe ratios of light or exposure. Each change in stop refers to a change by a factor of two — an added stop is double the light or exposure, and each subtracted stop is half the light or exposure. A one-stop unit is also referred to as the exposure value (EV) unit. Aperture stops are adjusted by changing f-stops, and increasing or decreasing f-stops involves doubling or halving the size of the area of the aperture pupil.

Stop Up/Down. Adjusting the aperture of the camera lens to control the amount of light that enters the camera. Stopping up light by one stop means opening up the aperture to the next lower number on the f-stop scale, thereby doubling the amount of light entering the camera. To stop down means to close the aperture to the next highest number, halving the light.

Straight Photography. Also known as pure photography.

Street Photography. A genre of photography that captures everyday life and human interaction in public spaces, often in urban environments and on sidewalks and streets (hence the name). Practitioners aim to capture candid, spontaneous moments and emotions in an unposed and unstaged manner to create an artistic record of that place and time.

Strobe. Another term for flash. While strobe and flash are typically used interchangeably in modern photography, a strobe often refers to a larger type of off-camera flash that is not mounted to a camera’s hot shoe while a flash is a more general term that can include both on-camera and off-camera devices.

Sunny 16. A rule of thumb for determining the correct exposure settings for outdoor photography in full sunlight. It states that on a sunny day, when the ISO is set to 100, the correct aperture should be f/16 and the correct shutter speed should be the reciprocal of the ISO (e.g. ISO 100 and 1/100s shutter speed). This rule can be useful for photographers who don’t have a light meter and want to estimate a proper exposure quickly.

Super-Telephoto Lens. A lens with an extreme telephoto focal length designed to shoot close-up photos of far-away subjects in fields such as sports, wildlife, and news photography. While there is no exact standard for what distinguishes a standard telephoto lens from a super-telephoto lens, any lens with a focal length greater than about 300mm is generally considered to be a super-telephoto.

Sync Speed. Also known as flash sync speed, this is the maximum shutter speed a camera can use while still synchronizing with an external flash unit. If shutter speed is set any faster than this limit, the camera’s shutter will not fully open before the flash has completed its exposure, causing a dark band in the image. The sync speed can vary depending on the camera and flash setup but is typically around 1/200 to 1/250 of a second. To go beyond this native sync, flashes commonly offer a feature called high-speed sync (HSS).

T

Teleconverter. An accessory that fits between a camera and lens to extend the focal length of the attached lens, typically by 1.4x or 2x. Tradeoffs generally include less light transmitted, poorer image quality, and slower autofocus.

Telephoto Lens. A type of lens designed to capture distant objects with a magnified field of view. They have a longer focal length than normal lenses, which allows them to bring far-off subjects closer and capture more detail. Telephoto lenses are often used by photographers in genres such as sports, wildlife, and portrait photography.

Tethered Shooting. When a photographer’s camera is physically connected to a computer or other device during a photo shoot, usually through a USB cable or wireless link. This setup allows the photographer to view the images on a larger screen in real time and make adjustments to the camera’s settings, such as focus and exposure. Tethered shooting is commonly used in professional studio photography, product photography, and other applications where precision, review speed, and control are important.

TIFF. Tag Image File Format. Also abbreviated TIF, this is a file format for storing raster graphics images that is commonly used in photography. TIFF files can store photos in a lossless format, meaning image quality is not lost when images are edited and resaved, making it popular as an archival format.

Tilt-Shift Lens. A type of camera lens in which the orientation of the lens relative to the camera body can be adjusted, allowing the photographer to control the plane of focus, shift the perspective, and correct distortion. Tilt-shift lenses are commonly used in architectural, product, and landscape photography to correct perspective distortion and create a selective focus effect.

Timelapse. A photography technique where a series of photos are taken over a specific period of time and then played back in rapid succession to create a video that appears to show fast motion or the rapid passage of time. The interval between each photo can range from a few seconds to several hours, depending on the desired effect. If the camera moves a significant distance during the video, it is often referred to as a hyperlapse.

Tonal Range. The full range of brightness levels in an image, or the number of distinct values of gray, from the darkest blacks to the brightest whites.

Tripod. A three-legged stand used to support a camera to keep it stable and reduce shake during the course of a photographic exposure, particularly with slow shutter speeds and/or in low-light environments.

TTL. Through the lens. A method of metering light in which the intensity of light that’s reflected from the scene is measured through the lens, as opposed to having a separate light detector or an off-camera light meter. Also a flash mode that uses the camera’s built-in light metering to determine optimal flash output for the correct exposure.

Twin-Lens Reflex (TLR). A type of camera that uses two lenses of the same focal length. One of the lenses is used for the viewfinder system while the other is used to capture the photograph.

U

Umbrella. A lighting accessory, shaped like a rain-blocking type of umbrella, that is used to soften and diffuse light from a flash or continuous light source. Umbrellas come in two main types: shoot-through umbrellas, which allow light to pass through the material and be redirected toward the subject, and reflector umbrellas, which reflect the light back toward the subject after bouncing it off the inside of the umbrella

Underexposure. When an image is captured with too little light, either due to camera settings or the lack of light available, resulting in a dark or dim image. This can cause a loss of detail in the shadows and darker areas of the image and may make colors look dull or washed out.

Urban Exploration. Also known as urbex, this is a type of photography that focuses on capturing the beauty and history of abandoned or forgotten urban spaces, such as buildings, tunnels, and infrastructure. Urban explorers and photographers often seek out and enter these off-limits spaces (possibly trespassing in the process) to document the decay, graffiti, and other unique features that are not seen by the general public.

V

V-flat. A large, flat panel, usually made of foam board or cardboard, used in photography as a lighting tool to modify the light in a scene. The “V” shape created when two panels are placed together allows for more precise control of light reflections, highlights, and shadows. They can be used to reflect light onto a subject or to block light, creating negative fill.

Vibrance. A smart photo-editing tool coined by Adobe and found in software such as Photoshop and Lightroom that allows a photographer to increase the saturation of less-saturated colors while leaving already-saturated colors unchanged.

Viewfinder. A device in or attached to a camera that a photographer looks through to frame and compose the shot. There are optical viewfinders (OVF) with a view of the real world, electronic viewfinders (EVF) with a view on a small digital display, or hybrid viewfinders that combine the two.

Vignetting. When the corners of an image appear darker or have reduced brightness compared to the center of the image. This effect can be naturally occurring due to the design of the lens, or it can be added artificially during post-processing to create a desired aesthetic effect.

W

Watermark. A translucent or transparent logo or graphic image added to a photo to assert ownership or protection against unauthorized use. It is typically placed in a noticeable location on the photo, such as the center or corner, to make it difficult to remove or crop out. The purpose of a watermark is to prevent image theft, establish copyright over the image, or show a preview to a client without delivering the final product.

Wedding Photography. The genre of photography that involves capturing the moments and memories of a couple on or around their wedding day. A wedding photographer may be hired to shoot everything from the ceremony and reception to portraits of the couple at a different location.

White Balance (WB). The adjusting of color intensities in a scene that have a color cast caused by different light sources with different color temperatures. The goal is usually to reach natural/correct colors that reflect what the human eye sees.

Wide-Angle Lens. A lens with a short focal length that allows for capturing a wider field of view than a standard or normal lens. It’s often used in landscape, architectural, and interior photography to capture more of the scene in a single shot. The wider field of view means that subjects at the center of the frame will appear smaller in relation to those at the edges, which can result in a more dramatic perspective and a sense of depth. A lens is typically considered to be wide-angle when it has an angle of view greater than 64°, or the equivalent of a 35mm lens in full frame.

Wide Open. Shooting with the lens aperture set to its maximum aperture, or the smallest f-number, such as f/1.4 or f/2. This results in a very shallow depth of field, a blurred background, and increased light.

Wildlife Photography. A genre of photography that focuses on capturing images of wild animals and their habitats. It can include capturing images of individual animals, groups of animals, or entire ecosystems and landscapes.

X

Y

Z

Zebra Pattern. A visual representation of the exposure values on a camera’s viewfinder or LCD screen, typically in the form of diagonal striped lines (hence the name) over portions of a scene or image that are overexposed. These alerts help a photographer or videographer prevent scenes from being “blown out” with clipping and lost details in the highlights.

Zone System. A systematic approach developed by Ansel Adams for determining and controlling the exposure values in a photograph. It assigns a series of 11 brightness values, or “zones,” to a scene, with Zone 0 being pure black and Zone X (Roman numeral 10) being pure white. By understanding the relationship between these zones, a photographer can visualize the final image and make precise exposure decisions to control the placement of tones within the image.

Zoom. The ability of a lens to change its focal length and magnify a subject from a distance. A zoom lens allows a photographer to change the angle of view and perspective of a scene without physically moving closer to or further away from the subject. This can be particularly useful for capturing images of wildlife, sports, and other subjects that are difficult to approach. Zoom can be either optical (adjusting the position of lens elements to achieve the magnification) or digital (a lower-quality result achieved by essentially cropping the photo).

0-9

35mm. The film gauge that became the dominant film format in film photography. The name “35mm” refers to the width of the film strip from edge to edge. While frames were recorded vertically on the film in filmmaking, Leica pioneered the use of the film horizontally for still photography, with each frame measuring 24x36mm. Kodak named the format 135 film in 1934, and 35mm film rolls (also known as cassettes or cartridges) became the dominant standard for consumer photography for decades — passing 120 film in popularity in the late 1960s — before the introduction of digital photography. Full frame sensors in digital cameras are based on the 24×36mm frame size of 35mm film, and these sensors are the standard by which the “crop factor” of all other sensor formats is measured.

35mm Equivalent. The field of view of a particular lens and film/sensor size combo compared to the field of view on a traditional 35mm “full frame” camera.

500 Rule. A guideline for determining the maximum shutter speed you can use to capture sharp stars without producing star trails in your night sky photography. The 500 rule states that you should divide 500 by the focal length of your lens to get the maximum shutter speed in seconds. For example, if you’re using a 50mm lens, the maximum shutter speed would be 500 / 50 = 10 seconds.

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