- backlighting
- If the subject of your picture is set against strong light eg a person standing in front of a bright window your camera will record the subject as a silhouette on your print. Use your flash to lighten up the subject in the foreground and control the effects of backlighting.
- Bandwidth
- refers to the amount of data that can be transferred over the Internet in a given amount of time. A 14.4 kbps modem has a very narrow bandwidth and is very slow. A T-100 ISDN link has a high or broad bandwidth and is very fast.
- Bit Depth
- The number of binary data bits used to record the brightness of each pixel per color channel. To achieve the illusion of continuous tone requires 256 levels of brightness from black (0) to white (255). This requires 8 bits binary. Since it takes three channels (Red Green & Blue) to represent color we need 24 bit (3x8) color to achieve full color RGB output and 32 bit color for CMYK.
- Bit-Mapped
- images represent the artwork as a grid of colored dots called Pixels. Paint and image-editing programs such as Painter and Photoshop are bit-mapped images. (See also: Rasterize and Vector Graphics)
- Bleed
- When a picture extends to the extreme edge of a page it is said to bleed. A full page bleed has an image covering the entire page with no borders. In order to give the printer some leeway in trimming a page with a bleed image you need to provide an image that extends beyond the crop marks. This extra area is called bleed and is usually 1/8 or 1/4 inch.
- blurring
- Blurred images are mostly caused by camera shake. If you make slight body movements during exposure you may unintentionally 'shake' your lens. Camera shake is more of a problem when shooting in dim light because you need to use a slower shutter speed but if you use a shutter speed of 1/125 seconds or above you can avoid blurring.
- Brightness
- The apparent level of light emitted by or reflected from an object. The Brightness Range of an image is measured from the darkest black to the brightest white.
- Bubble Jet
- see Ink Jet
- bulb setting
- Despite its name the bulb setting has nothing to do with flash photography. Identified as 'B' on your shutter speed scale or programme mode it keeps the shutter open for as long as you keep your finger on the shutter release. You can use it at night-time for instance to create trailing lines of light from moving car headlights.
