Glossary - Diane Downs


Ambient Light - Existing light within a room. This can be from the windows, lamps, or any items that glow.

Aperture - The opening of the lens through which light passes. The size of the aperture is shown as f/2.0 up to f/22. The lower the number, the more open the hole becomes. If the number is higher, less light is passing through.

Aperture Priority Mode - Function of the camera that allows the user to set the aperture. The camera chooses the ISO and shutter speed.

Aspect Ratio - The relationship of the width to the height within an image. Used for cropping (examples: 2:3, 4:3).

Backlight - Illumination of subjects from behind. Blown: When a portion of the image is so bright that the area has turned to pure white and lost all detail.

Bokeh - The blur and out of focus area of an image.

Burn - A term that derives from film. Burning refers to darkening a portion of an image.

Catchlights - The reflection of light in a subject’s eyes.

Clipped - An area of an image that is extra dark or saturated to the point of losing detail.

Chromatic Aberration - Color fringing of blues and purples that is usually found around the edges of items within an image.

Composition - The arrangement of visual elements in an image. Contrast - The difference between an image's lightest and darkest tones.

Conversion - Changing an image from color to black and white. Depth of Field - The portion of an image that appears sharply in focus.

Digital Zoom - A zooming effect that is not true zooming, but instead enlarging pixels within an image (typically seen with Point and Shoot cameras and mobile cameras).

Diptych - Two images intended to be displayed together. DNG - Digital negative. A lossless file format created by Adobe with the intent of long-term storage and archiving of digital photos.

Dodge - A term that derives from film. Dodging refers to lightening portions of the image.

DSLR digital single-lens reflex camera - A digital camera that uses a mechanical mirror system and a pentaprism to direct light from the lens to a viewfinder on the back of the camera. Utilizes interchangeable lenses.

Exposure - The amount of light used to create an image. External flash - An external mount strobe flash attachment for a DSLR.

EXIF - The data information stored within your image file. Holds information such as, ISO, shutter speed, aperture, lens, etc.

F-Stop - A measurement that expresses the diameter of an aperture. Focal Length - The length of the lens, such as 50mm, 85mm, 105mm.

Grain - Also referred to as ‘noise’ is sand-like dots on an image due to the sensitivity of the ISO setting used. The higher the ISO setting, the more grain is introduced.

Gray Card - A gray card that, when used with a reflective light meter, can help produce consistent image exposure. It is also helpful when setting the white balance manually.

ISO - A setting that determines how sensitive the image sensor is to light. It is the digital equivalent to film speed. Raising your ISO will allow you let more light in, but will also being to introduce grain.

JPEG - A compressed image file format, standard for photographs. It is a lossy format, meaning when adjustments are made to the image (typically in post processing) part of the image quality is lost.

Kelvin - Color temperature of an image. The photographer can set their Kelvin temperature, in camera, to choose their preferred white balance.

Lens flare - A visual effect that is created when very bright light (typically the sun) enters the lens and hits the camera's digital sensor.

Macro - An extremely close up image.

Manual Mode - A camera mode that allows the user to choose the aperture, shutter speed and ISO when shooting.

Metering - Using a light meter (modern day digital cameras have them within) to determine the amount of light within a scene.

Monochrome - Shades of black and white.

Negative space - The space around and between the subject of an image.

Optical Zoom - Found with a zoom lens, optical zoom gives a true zoom effect, moving closer to the object in the image.

Overexposure - An image that receives too much light often resulting in portions of the image losing detail in bright areas.

Perspective - The way in which objects appear to the eye based on their spatial attributes.

Photographic triangle - The mathematical relationship between aperture, shutter speed and ISO.

Point and Shoot- Simple automatic cameras that require the user to press only one button to take an image.

Prime Lens - A fixed focal length lens that does not zoom. Prime lenses are typically clearer, sharper and have a larger maximum aperture.

Processing - A method of editing and printing digital images.

Proper exposure - When an image has the correct amount of light with no areas at the extreme edges of the light spectrum (either blown out or too dark).

RAW - Often referred to as a “digital negative”, a RAW file holds the most possible data and is unprocessed.

Rule of Thirds - A means of composing an image with your subjects or important pieces on the lines created when breaking an image into thirds.

Resolution - Refers to the pixels per inch within an image that determines the size. Saturation - The intensity of color.

Shutter speed - The amount of time the shutter is open. A fast shutter speed will let less light in but freeze motion. A slow shutter speed will let more light in but can create blur or out of focus images.

Shutter Priority Mode - Function of the camera that allows the user to set the shutter speed. The camera chooses the ISO and aperture.

Speedlight - An external flash that attaches to the camera.

Telephoto Lens - A longer focal length that magnifies an image bringing the subject closer than they appear to the naked eye.

Tonal contrast - The difference between the light and dark areas in an image. The greater the difference, the more the area attracts.

Viewfinder - The part of the camera the photographer looks through to compose the image.

Vignette - A visual effect showing darkening around the outer edges of an image. This can be caused by the lens used, obstruction, or purposefully created in post processing.

White balance - The camera’s attempt to make the white areas of an image, ‘white’; based on the temperature of light (see Kelvin). The camera will often have multiple settings or can choose automatically.

Wide Angle Lens - A shorter focal length that is wider than the naked eye and can create distortion or a fish eye effect. Typically used in landscape photography.

Underexposure - An image that receives too little light often resulting in portions of the image being too dark to be seen.

Zoom Lens - A lens with a changing focal length, sometimes with a small range and others with larger ranges.