Photo Editing Terms
Below is the beginning of a list of common photo editing terms and their definitions you may find useful as you get more involved with Photoshop or other photo editing software. Some terms have multiple meanings depending on the context they are being used, in these cases I will attempt to list the separate meanings.
The relationship of the height of a photo to its width. A common ratio for many modern digital cameras is 3:2. However common print sizes are 4x6, 5x7, 8x10 and so forth, you must realize the aspect ratio of the camera's image does not always match up with all print sizes unless you were to either crop an image or add extra blank space.
In its simplest of meanings the brightness of an image refers to the overall "lightness" of an image. In the Brightness/Contrast adjustment in Photoshop adjusting the brightness of an image affects all values in an image by either lightnening or darkening them linearly.
In digital photography and digital video, clipping is a result of capturing or processing an image where the intensity in a certain area falls outside the minimum and maximum intensity which can be represented. The clipped area of the image will typically appear as a uniform area of the minimum (black) or maximum (white) brightness, losing any image detail. The amount by which values were clipped, and the extent of the clipped area, affect the degree to which the clipping is visually noticeable or undesirable in the resulting image.
An overall, sometimes subtle, undesirable, color shift in an image. This shift is may be described as a particular color (i.e. R, G, B, C, M, Y) or simply as warm or cold.
Luminance — the relative difference between light and dark areas of an image. Color — Colors that geneally lie on the opposite sides of the color wheel are considered to contrast one another (i.e. Red and Cyan)
Depth of Field
Depth of field refers to the area in a photograph, from the nearest to the furthermost points from the camera, which appears to be in sharp focus.
A "correct" exposure is when the shutter speed, f-stop, and film speed are set to properly render a scene. In more simple terms, the photo is neither too dark nor too light. Cameras with manual settings require the photographer to properly set the shutter speed, aperture for the selected film speed (ISO or ASA for you old school photographers) or in digital terms, sensor sensitivity. See Matthew Cole's detailed explanation here.
A fill light (often simply fill) may be used to reduce the contrast of a scene and provide some illumination for the areas of the image that are in shadow.
The area in a photo that is sharp. This is adjusted by turning the barrel of most lenses on a SLR style camera. Areas closer and further from the lens will appear blurry.
The lightest area of a photo that is not pure white. It will have a slight coloration or show a small amount of detail.
The histogram is a graphical representation of the number of pixels in your image at any of 256 lightness levels. Lightness Levels run from black to white from left to right on the horizontal scale and the number of pixels at each level are represented vertically. Here is a good explanation with diagrams.
Often misunderstood, hue, simply is what most people generally mean when they speak of color. Hue is broken down into two sets of primaries, subtractive (C,M,Y) and addative (R,G,B).
The tonal range in the center of the range from black to white, middle gray tones.
With respect to color "neutral" would be the absence of color, as in a gray tone.
Saturation refers to the dominance of hue in the color. You may also define it as the intensity of a hue or how vivid it appears
The darkest area of a photo that is not completely black. It may have some coloration and also retain some amount of detail.
As used by Adobe in Lightroom and Camera Raw: Adjusts the saturation so that clipping is minimized as colors approach full saturation. Vibrance also prevents skintones from becoming over saturated.