Welcome to my A–Z glossary of wildlife photography and general photographic terms. This glossary focuses solely on camera terminology, universal phrases, and acronyms you may encounter while practising the art of photography.
The glossary is arranged alphabetically to make it easy to find specific terms, and you can click the letters below to jump directly to any section.
For wildlife habitat, behaviour, or fieldcraft definitions, you may also find my A–Z Glossary of Wildlife Behaviour and Fieldcraft Terms helpful.
A
Autofocus (AF)
Autofocus is the camera’s ability to automatically adjust the focus on your chosen subject to ensure it is rendered sharply.
AF-C / AI-Servo
AF-C / AI-Servo is a specific autofocus mode that actively tracks and analyses moving subjects until an exposure is made.
AF-S / Single Shot
AF-S / Single Shot is an autofocus mode that locks focus on your subject once, rather than actively tracking it. Typically used for static subjects.
AF Point
An AF Point is a specific point or area that the camera uses to focus.
Aperture
Aperture is the opening of a lens that controls how much light reaches the camera sensor. It is one of the three core components of the exposure triangle and is used to control the Depth of Field.
Aperture Priority (A/Av)
Aperture Priority (A/Av) is a camera shooting mode which allows the user to have full control over the aperture and, therefore, depth of field. In aperture priority mode, shutter speed is automatically set based on a combination of the available light, aperture, and ISO settings.
Aspect ratio
Aspect ratio is the proportional relationship between an image’s width and height. Examples include: 3:2, 5:7, 1:1, 4:5.
B
Back-button focus
Back‑button focus is a technique that assigns autofocus control to a rear button instead of half‑pressing the shutter release. It allows you to simulate all three focusing behaviours without changing AF modes: press and hold the back button for continuous focus, press once and release for a single‑shot lock, and don’t press it at all to use manual focus via the lens’s focus ring.
Bokeh
Bokeh is the term used to describe the pleasing aesthetic quality of out-of-focus areas of an image created by using a shallow depth of field.
Burst mode
Burst mode is the camera’s ability to shoot a consecutive burst of frames without stopping.
C
Chromatic aberration
Chromatic aberration, also known as colour fringing, is a distortion of colour that usually appears along the edges of objects in high contrast scenes. It’s often more prominent in cheaper lenses and can generally be corrected in post-processing software.
Clipping
Clipping refers to areas of an image where detail is lost because the tones are too bright (blown highlights) or too dark (crushed shadows) for the sensor to record. On a histogram, blown highlights touch the right edge of the graph, and unrecoverable shadows touch the left edge.
Contrast
Contrast is the difference in intensity between the brightest and the darkest parts of an image.
Crop factor
The crop factor, or focal length multiplier, is the ratio between the size of a camera’s sensor and a 35mm full-frame sensor. For example, Canon APS-C cameras apply a 1.6x focal length multiplier. A 50mm lens used with a Canon crop‑sensor body provides a field of view equivalent to an 80mm lens on a full‑frame camera.
D
Depth of Field (DOF)
Depth of Field (DOF) is the area of acceptable sharpness in an image. Depth of Field can be influenced by aperture, focal length, and subject distance.
DSLR
DSLRs, or Digital Single‑Lens Reflex cameras, are interchangeable‑lens cameras that use a mirror and prism system to reflect light from the lens into an optical viewfinder. When the shutter is pressed, the mirror flips up, allowing light to reach the camera’s sensor.
Dynamic range
Dynamic range is the range of tones a camera sensor can capture from the darkest shadows to the brightest highlights before data is clipped and lost.
E
Electronic viewfinder (EVF)
An electronic viewfinder is the mirrorless camera equivalent of an optical viewfinder found on DSLRs. Electronic viewfinders use a small LCD or OLED display to show a real-time preview of the scene based on information captured by the sensor.
Exposure
Exposure is the amount of light that reaches the sensor. It is controlled by the three elements of the exposure triangle: shutter speed, aperture, and ISO. A correctly exposed image relies on a fine balance of all three settings.
Exposure compensation
Exposure compensation is a method of manually increasing or decreasing overall exposure when using automated or semi‑automated shooting modes such as aperture priority or shutter priority. It is particularly useful in dynamic conditions where the camera may struggle to correctly expose dark subjects against bright backgrounds, or bright subjects against dark backgrounds.
Eye detection
Eye detection is an autofocus setting commonly found on mirrorless cameras. It allows the camera to detect, prioritise, and track the eyes of your subjects, helping ensure consistently sharp focus.
F
F-stop
An F‑stop is a measurement representing the size of a lens’s aperture. In photography, you’ll often hear the terms wide open and narrow. Wide open refers to the widest aperture your lens supports; an F‑stop with a low number, such as f/1.4, f/1.8, or f/2.8. Narrow refers to a high F‑stop value, such as f/22. The bigger the number, the narrower the aperture and the greater the depth of field.
Focal length
Focal length is a measurement in millimetres that determines a lens’s angle of view and magnification. Wide-angle lenses have a shorter focal length and allow for a broader field of view. Telephoto lenses have longer focal lengths and a narrower field of view, and greater magnification.
Focusing ring
A focusing ring is a band around the circumference of a lens that can be rotated clockwise or counterclockwise to adjust focus manually.
Frame rate (fps)
Frame rate (fps) is the number of continuous frames a camera can capture each second when shooting in burst modes.
G
Grain
Grain is the textured, speckled appearance seen in images, originating from the physical grain structure of film. In digital photography, a similar effect is often referred to as noise, though the two are not identical.
H
High-speed sync (HSS)
High‑speed sync (HSS) is a flash technique that allows you to shoot with shutter speeds faster than your camera’s maximum sync speed. The flash achieves this by pulsing rapidly throughout the exposure, rather than firing a single burst of light.
Histogram
A histogram is a graph showing the distribution of tones in an image, ranging from pure black on the left of the x‑axis to pure white on the right. It is useful for managing exposure and ensuring that highlights or shadows are not clipped at either end of the scale.
I
Image stabilisation (IS)
Image stabilisation (IS) is a technology that reduces blur caused by camera shake when using slower shutter speeds. Stabilisation can be built into specialised lenses or into the camera body itself (known as In‑Body Image Stabilisation, IBIS). When used together, lens‑based IS and IBIS can work in combination for improved performance.
Intentional Camera Movement (ICM)
Intentional Camera Movement (ICM) is a creative technique where the camera is deliberately moved during an exposure to produce artistic blur. This is often done using slower shutter speeds to enhance the aesthetic of the motion.
ISO
ISO is one of the three core components of the exposure triangle, controlling the camera’s sensitivity to light. ISO itself does not create noise; it amplifies the signal captured by the sensor, which also amplifies the noise already present. Each time the ISO value doubles (for example, from ISO 100 to 200), you gain one stop of exposure.
J
JPEG
JPEG is a compressed image file format that reduces file size by discarding some data, while still retaining good overall image quality.
K
Kelvin (k)
Kelvin is a universal measurement of colour temperature, used to describe and control white balance in cameras.
L
Live view
Live view is a method of composing an image using the digital display on the back of a camera instead of the viewfinder. Live view can show useful tools such as the histogram, gridlines, and exposure settings to help guide the image‑making process.
Long exposure
A long exposure is a technique that uses a slow shutter speed, such as five seconds, thirty seconds, or longer, to capture movement or to allow more light into the camera to overcome low-light conditions.
M
Manual mode (M)
Manual mode (M) is a shooting mode that gives you complete control over the exposure triangle, allowing you to independently adjust ISO, aperture, and shutter speed. ISO can still be automated if required via the camera’s settings.
Megapixels
Megapixels are a unit of measurement describing the resolution of a camera’s sensor. Each megapixel represents one million pixels; the more megapixels a sensor has, the higher the potential resolution of an image.
Metadata
Metadata is information embedded into digital images. RAW files in particular store extensive EXIF data such as exposure settings, focal length, lens make and model, time and date of capture, GPS coordinates, and more.
Metering
Metering is the process a camera uses to determine the brightness of a scene. The camera evaluates the light according to the selected metering mode: evaluative, spot, or centre‑weighted.
Minimum shutter speed
Minimum shutter speed is a setting that instructs the camera not to drop below a certain shutter speed. When light levels change, the camera will automatically adjust ISO to maintain or exceed this minimum value. This is useful in situations such as photographing moving birds or fast‑moving subjects.
Minimum focus distance
Minimum focus distance is the closest distance at which a lens can focus.
Mirrorless
Mirrorless cameras are a modern advancement of the DSLR. Instead of using a mirror system, mirrorless cameras rely on light hitting the sensor directly, which then projects a real‑time view of the scene onto an electronic viewfinder (EVF) or rear display.
Motion blur
Motion blur describes the streaking or smearing effect that occurs when movement is captured during an exposure. It can be accidental (caused by camera shake or subject movement) or deliberate, such as when using ICM for creative effect.
N
Noise
Noise is a signal that creates a grainy or speckled texture in images and can reduce overall sharpness. Noise is always present in every digital image, but becomes more visible as ISO increases because the sensor’s signal is amplified along with the noise already present. Modern mirrorless cameras generally offer excellent high‑ISO performance, producing cleaner images than older DSLRs. Noise can be reduced or removed using most post‑processing software.
O
Overexposed
Overexposed is a term used to describe an image produced when too much light hits the sensor. Overexposed images feature blown highlights, data that can’t be recovered. On a histogram, this appears as data pushed up against the right‑hand side of the x‑axis.
Optical viewfinder
An optical viewfinder is the primary viewfinder used on DSLR cameras. It shows the scene as seen through the camera lens via a system of mirrors and a pentaprism (or pentamirror), providing a direct optical view without electronic processing.
P
Panning
Panning is a technique used to track a moving subject with your camera as it travels across a scene. When done correctly, panning keeps the subject sharp while creating a smooth, blurred background, helping the subject stand out and emphasising its speed.
Pixel peeping
Pixel peeping is the process of judging an image’s sharpness and overall quality at very high magnification. Strong images can sometimes be unfairly dismissed when minor imperfections are found at extreme zoom levels, imperfections that would be invisible during normal viewing.
Prime lens
A prime lens is a lens with a fixed focal length. Unlike zoom lenses, a prime lens cannot change focal length, so you need to move around your subject or change lenses to adjust your composition.
R
RAW
RAW images are large, uncompressed (or minimally compressed) file types that capture all of the data recorded by the camera’s sensor. RAW files are preferred for post‑processing because they offer far greater flexibility and creative control than JPEGs. Different camera brands use different RAW extensions. Canon, for example, uses CR2 and CR3.
Resolution
Resolution is the number of pixels in an image or on a camera’s sensor. Higher resolution allows for greater detail and larger prints, but also results in bigger file sizes.
Rolling shutter
Rolling shutter is a type of distortion that can appear in fast‑moving subjects or during rapid camera movement when using the electronic shutter. With an electronic shutter, the sensor is read line‑by‑line rather than capturing the entire image at once, which can cause leaning or distorted shapes.
S
Shutter priority (Tv)
Shutter priority is an automatic shooting mode that gives you full control over the camera’s shutter speed. The camera automatically selects the aperture based on available light and the chosen ISO setting.
Shutter speed
Shutter speed is the length of time the shutter remains open, allowing light to reach the sensor during an exposure. Shutter speeds can be slow (several seconds or longer) or fast (fractions of a second), depending on available light, the exposure triangle, and creative intent.
Spot metering
Spot metering is a metering mode that instructs the camera to measure the brightness of a scene based on a very small area, often around the centre focus point.
Subject detection
Subject detection is a feature found in modern mirrorless cameras and some higher‑end DSLRs that allows the camera to recognise and prioritise specific subjects. By identifying the subject, such as a person, animal, bird, or vehicle, the camera can track it more accurately, using AI‑driven algorithms to predict movement.
T
Tracking AF
Tracking AF is an autofocus mode that actively follows a subject as it moves around the frame. Tracking sensitivity can often be adjusted to control how “sticky” the tracking is: how readily the camera stays locked onto the subject or switches to something else.
Teleconverter
A teleconverter is an optical attachment that fits between the camera and the lens to increase the effective focal length. Teleconverters come in different magnifications, such as 1.4x or 2x, but using one reduces the amount of light reaching the sensor and can, in some cases, affect image quality and autofocus performance.
Telephoto lens
A telephoto lens is a lens with a longer focal length and greater magnification than wide‑angle lenses. Lenses around 100mm are often considered short telephoto, while lenses over 400mm are typically referred to as super‑telephoto.
Tack sharp
Tack sharp is a term used to describe an image or subject that is perfectly in focus, with crisp, clear detail.
U
Underexposed
Underexposed describes an image produced when not enough light has reached the sensor. Underexposed images feature crushed shadows, data that can’t be recovered. On a histogram, this appears as data pushed up against the left‑hand side of the x‑axis.
V
Viewfinder
A viewfinder is the window you look through to compose and preview an image. In mirrorless cameras, it displays a digital preview created from the sensor (an electronic viewfinder, or EVF). In DSLRs, it provides an optical preview using a system of mirrors and a pentaprism or pentamirror.
Vignetting
Vignetting describes the falloff of light toward the edges and corners of an image compared to the centre. It can occur naturally when using wide‑angle lenses at wide apertures, and the effect can be increased by filters such as polarisers. Vignetting can also be added intentionally in post‑processing software to emphasise a subject or reduce the visual weight of the edges of a frame.
W
White balance
White balance is the colour temperature of the light in an image, measured in Kelvin (K). Cameras offer a range of white balance presets to match different lighting conditions, or you can let the camera choose automatically using Auto White Balance (AWB). When shooting in RAW, white balance can be freely adjusted during post‑processing.
Wide-open
Wide‑open refers to using a lens at its widest aperture (the smallest f‑number), such as f/2.8 or f/4.
Wide angle
A wide‑angle lens is any lens with a short focal length that captures a wider field of view than a standard lens, typically wider than what the human eye naturally sees.
Working distance
Working distance is the physical distance between the front of the lens and your subject. It is especially important in macro and close‑up photography, where small changes in distance can affect focus, depth of field, and composition.
Z
Zoom lens
A zoom lens is a lens with a variable focal length. The focal length can be adjusted freely while composing an image, offering greater flexibility than a prime lens. Zoom lenses can cover broad focal‑length ranges, for example, 100-400mm, allowing one lens to replace several primes.
Zone AF
Zone AF is an autofocus mode that uses a cluster of focus points to track subjects. The user can select the specific zone, allowing the camera to prioritise focus within that area while supporting the chosen composition.