Terms starting with G
23 terms
Gamma
The non-linear relationship between stored numerical values and displayed brightness in a colour space or on a device.
Colour & Colour ManagementGamut
The complete range of colours a device, medium or colour space can produce or record.
Colour & Colour ManagementGamut Mapping
The process of converting colours from a larger space into a smaller one while preserving as much of the image's appearance as possible.
Printing, Display & OutputGamut Warning
A soft-proofing overlay that flags pixels whose colours the destination profile cannot reproduce.
Files, Metadata & WorkflowGeotagging
Recording the latitude, longitude and sometimes altitude of an image's capture point in its metadata.
Composition & Visual DesignGestalt Principles
A set of observations from perceptual psychology describing how the visual system groups separate elements into wholes.
Optics, Lenses & FiltersGhosting
Distinct secondary images of a bright light source formed by reflections bouncing between lens element surfaces.
Printing, Display & OutputGiclée
A marketing term for a fine-art inkjet print, generally implying pigment inks on archival paper.
Cameras, Formats & SystemsGimbal Head
A tripod head that supports a long lens at its centre of gravity, letting it swing weightlessly in two axes.
Motion, Video & Creative TechniquesGimbal Stabiliser
A motorised three-axis mount that holds a camera level and steady while the operator moves.
Cameras, Formats & SystemsGlobal Shutter
An electronic shutter that starts and stops the exposure for every photosite at exactly the same instant.
Printing, Display & OutputGloss Differential
A visible difference in surface sheen between inked and uninked areas of a glossy print.
Printing, Display & OutputGlossy Paper
Paper with a smooth, highly reflective surface that maximises apparent contrast and colour saturation.
Lighting & FlashGobo
An opaque cut-out or template placed in a light's beam to cast a shaped pattern onto a subject or background.
Lighting & FlashGolden Hour
The period shortly after sunrise and before sunset when the sun is low, and its light is warm, soft and strongly directional.
Composition & Visual DesignGolden Ratio
The proportion of approximately 1:1.618 that has been used in art and architecture as a compositional division.
Composition & Visual DesignGolden Spiral
A logarithmic spiral constructed from golden-ratio rectangles, sometimes overlaid on a frame as a compositional guide.
Composition & Visual DesignGolden Triangle
A compositional grid formed by a diagonal across the frame and two perpendicular lines from the remaining corners.
Post-Processing & RetouchingGradient Mask
A mask that fades an adjustment smoothly along a linear direction, digitally imitating a graduated filter.
Optics, Lenses & FiltersGraduated Neutral Density Filter
A filter that is dark at one end and clear at the other, used to hold back a bright sky while leaving the land unaffected.
Exposure & MeteringGrey Card
A physical card of known neutral 18 per cent reflectance, held in the subject's light to give both a reliable exposure reading and a white…
Genres, Movements & TheoryGroup f/64
A short-lived association of West Coast American photographers formed in 1932 to advocate sharp, unmanipulated photography.
Lighting & FlashGuide Number
A measure of a flash's power, equal to the product of the correct aperture and the subject distance at a stated ISO.