Photography Glossary — A-Z Terms Explained

A–D

Aperture — The adjustable opening in a lens that controls how much light reaches the sensor. Measured in f-stops (f/1.8, f/4, f/8). Lower numbers = wider opening = more light and shallower depth of field.

Bokeh — The aesthetic quality of out-of-focus areas in an image. "Good" bokeh has smooth, creamy blur; "bad" bokeh has harsh, distracting shapes. Influenced by aperture blade count and lens design.

Burst Rate (FPS) — The number of continuous frames a camera can capture per second. Higher burst rates (10-30fps) are essential for sports and wildlife photography.

CMOS Sensor — Complementary Metal-Oxide-Semiconductor. The most common sensor technology in digital cameras. Converts light into electrical signals to create digital images.

Crop Factor — The ratio of a sensor's size compared to full-frame (35mm). APS-C has a 1.5× crop factor; Micro Four Thirds has 2×. Multiply focal length by the crop factor to get the full-frame equivalent field of view.

Dynamic Range — The range of brightness a sensor can capture, from the darkest shadows to the brightest highlights, measured in stops. Higher dynamic range = more detail in shadows and highlights.

Depth of Field (DoF) — The zone of acceptable sharpness in an image. Controlled by aperture, focal length, and subject distance. Shallow DoF isolates subjects; deep DoF keeps everything sharp.

DSLR — Digital Single-Lens Reflex camera. Uses a mirror to reflect light to an optical viewfinder. Being replaced by mirrorless cameras in most applications.

E–I

EVF — Electronic Viewfinder. A small screen inside the camera body that displays a digital preview. Shows exposure, white balance, and effects in real time. Standard in mirrorless cameras.

Exposure — The amount of light that reaches the sensor. Determined by aperture, shutter speed, and ISO. Correct exposure produces an image that matches the photographer's creative intent.

Exposure Compensation — A control that makes images brighter (+) or darker (-) relative to the camera's metered exposure. Used in Aperture Priority and Shutter Priority modes.

F-Stop — The unit of measurement for aperture. Each full stop (f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16) doubles or halves the amount of light entering the lens.

Focal Length — The distance (in mm) from a lens's optical center to the sensor. Determines field of view and magnification. 50mm is "normal"; below 35mm is "wide"; above 85mm is "telephoto."

Full-Frame — A sensor measuring 36×24mm, matching the dimensions of 35mm film. Considered the standard for professional photography.

IBIS — In-Body Image Stabilization. A mechanism that moves the sensor to compensate for camera shake, allowing slower shutter speeds handheld. Measured in stops of stabilization.

ISO — The sensor's sensitivity to light. Low ISO (100-400) = clean images with less noise. High ISO (3200+) = brighter images but more grain/noise.

J–P

JPEG — A compressed image format that applies processing (sharpening, color, noise reduction) in-camera. Smaller files but less editing flexibility than RAW.

Kelvin (K) — The unit of measurement for color temperature. Daylight is approximately 5500K. Lower values (3000K) are warm/orange; higher values (7000K+) are cool/blue.

Lens Mount — The physical and electronic interface between a camera body and lens. Each manufacturer has proprietary mounts (Canon RF, Nikon Z, Sony E, Fuji X). Lenses are not cross-compatible without adapters.

Mirrorless — A camera type that uses an electronic viewfinder instead of a mechanical mirror. Smaller, lighter, and faster than DSLRs. The current industry standard for new cameras.

Noise — Random variations in brightness and color that appear as grain in digital images, especially at high ISO settings. Modern cameras produce less noise than older models at equivalent ISO.

Overexposure — An image that's too bright. Highlight detail is lost ("blown out"). Once highlights clip to pure white, no detail can be recovered in post-processing.

Phase-Detect AF — Autofocus system that uses paired pixels on the sensor to measure and correct focus distance. Faster and more accurate than contrast-detect AF. Used in all modern mirrorless cameras.

Prime Lens — A lens with a fixed focal length (e.g., 35mm, 50mm, 85mm). Generally sharper, faster (wider aperture), and lighter than zoom lenses at the same focal length.

R–Z

RAW — An unprocessed image file containing all data captured by the sensor. Maximum editing flexibility in post-processing. Always shoot RAW for professional work.

Rule of Thirds — A composition guideline that divides the frame into a 3×3 grid. Placing subjects at intersection points creates more dynamic and visually interesting images.

Shutter Speed — The duration the sensor is exposed to light. Fast speeds (1/1000s) freeze motion; slow speeds (1s+) create motion blur. Measured in fractions of a second.

Stop — A unit of measurement for light changes. One stop represents a doubling or halving of light. Used for aperture, shutter speed, ISO, and flash power.

TTL — Through-The-Lens metering for flash exposure. The camera fires a pre-flash, measures the light returned, and automatically sets flash power. Convenient but not always accurate.

Underexposure — An image that's too dark. Shadow detail is lost. Modern sensors can recover significant shadow detail from RAW files, making slight underexposure preferable to overexposure.

Vignetting — Darkening at the corners of an image. Can be caused by the lens design (optical vignetting) or intentionally added in post-processing for creative effect.

White Balance — A camera setting that adjusts colors to account for the color temperature of the light source. Ensures neutral whites under any lighting condition. Can be set in-camera or adjusted in post when shooting RAW.

Zone System — A photographic technique developed by Ansel Adams that divides the tonal range into 11 zones from pure black (Zone 0) to pure white (Zone X). Used for precise exposure control in landscape and fine art photography.