Photography Glossary

The adjustable opening in a lens through which light passes, measured in f-stops. Wider apertures (lower f-numbers) admit more light and reduce depth of field.

The aesthetic quality of the out-of-focus areas in a photograph, particularly the way point-light sources are rendered.

Capturing multiple shots of the same scene at different exposure values, typically used for HDR merging or to ensure at least one frame is perfectly exposed in challenging light.

A lens defect where different wavelengths of light are focused at slightly different points, producing colored fringing along high-contrast edges.

A measurement in Kelvin describing the color characteristics of a light source, from warm/orange (low K) to cool/blue (high K).

The ratio of a camera sensor's size to a full-frame (35mm) sensor. A 1.5x crop factor on an APS-C sensor makes a 50mm lens behave like a 75mm lens in terms of field of view.

The range of distances within a scene that appear acceptably sharp in a photograph, determined by aperture, focal length, and subject distance.

The ratio between the brightest and darkest luminance values a camera sensor can capture in a single exposure while retaining detail.

A camera control that allows the photographer to override the auto-exposure system by dialing in positive or negative stops of light.

A unit expressing the ratio of a lens's focal length to the diameter of its aperture opening. Each full f-stop (e.g., f/2.8 to f/4) halves the amount of light admitted.

The distance in millimeters from the optical center of a lens to the image sensor when the lens is focused at infinity, determining angle of view and magnification.

A technique that combines multiple exposures of the same scene to capture detail in both the deepest shadows and brightest highlights beyond a single exposure's capability.

A graphical representation of the distribution of brightness values in an image, from pure black on the left to pure white on the right.

Technology that compensates for camera shake using moving lens elements (optical) or a shifting sensor (in-body), allowing sharper handheld shots at slower shutter speeds.

A measure of the camera sensor's sensitivity to light. Higher ISO values allow shooting in darker conditions but introduce more digital noise.

An optical aberration where straight lines in a scene appear curved in the image. Barrel distortion bows lines outward (common in wide-angle lenses); pincushion distortion bows them inward.

The camera's process of measuring the brightness of a scene to determine proper exposure settings. Common modes include evaluative, center-weighted, and spot metering.

Random variations in brightness or color in an image, most visible in shadow areas and at high ISO settings. It appears as grain-like texture that degrades image quality.

A lens with a single fixed focal length, typically offering wider maximum apertures, sharper optics, and lighter weight compared to zoom lenses.

An unprocessed image file that contains all data captured by the camera sensor, offering maximum flexibility in post-processing.

The duration for which the camera's shutter is open during an exposure, controlling both the amount of light reaching the sensor and the rendering of motion.

Connecting the camera to a computer so that captured images transfer immediately to the screen for review, commonly used in studio and commercial photography for real-time assessment.

A reduction in image brightness or saturation at the periphery compared to the center, caused by lens optics or intentionally added in post-processing for artistic effect.

A setting that adjusts image color to compensate for the color temperature of the light source, ensuring neutral tones appear accurate.

A lens with a variable focal length range, providing versatility to frame subjects at different magnifications without changing lenses.