- Gamma
- The measure of the contrast of an image or imaging device.
- Gamut
- the range of colors and tones a device or colorspace is capable of recording or reproducing. The human eye can sense many more colors than can be reproduced on a computer monitor in RGB colorspace. The human eye has a larger Gamut than the computer monitor.
- GIF
- An indexed color file format. (see: File Formats)
- grain
- Grain is the speckled texture you sometime see in prints made from fast film. The coarse dots do not show fine detail but can give an unusual creative effect. Use high speed colour film such as ISO 1600 to photograph flowers or landscapes for an artistic painterly effect.
- greyscale
- In digital photography black-and-white pictures are known as greyscales. They have 256 fixed tones of grey which run from 0 (black) to 255 (white) with greys numbered 1 to 254 in between.
- guide number
- The guide number describes the power of a camera's flash eg 30. The higher the number the more powerful your flash and the further it will reach. On most compact cameras the built-in flash is only strong enough to light up a small room.
