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840 terms · page 9 of 35
Darkroom
Film, Darkroom & Historic Processes
A light-tight room equipped for processing film and making prints.
DCP Profile
Colour & Colour Management
A DNG camera profile, the file format used to describe a camera's colour response to raw processing software.
Dead Pixel
Sensors & Digital Capture
count
A photosite that records no signal at all, appearing as a permanently black point in every image.
Deconvolution Sharpening
Post-Processing & Retouching
%
A sharpening method that models how the image was blurred and mathematically reverses that blur.
Deep Depth of Field
Focus & Depth of Field
m
A wide zone of sharpness in which foreground, subject and background all hold detail.
Dehaze
Post-Processing & Retouching
%
A control that removes or adds atmospheric haze by estimating and correcting for scattered light.
Delta E
Printing, Display & Output
ΔE
A numerical measure of the perceived difference between two colours, used to quantify display and print accuracy.
ΔE = distance in CIELAB space
Demosaicing
Sensors & Digital Capture
The process of reconstructing a full-colour image from the single-colour samples recorded under a colour filter array.
Densitometer
Film, Darkroom & Historic Processes
density units
An instrument that measures the optical density of a negative, transparency or print.
Density
Film, Darkroom & Historic Processes
density units
A measure of how much light a processed negative or print blocks, expressed logarithmically.
D = log₁₀(1 / transmittance)
Depth Cues
Composition & Visual Design
The visual signals — overlap, relative size, convergence, haze and blur — that let a flat image suggest three dimensions.
Depth of Field
Focus & Depth of Field
m
The range of distances in front of and behind the plane of focus that appears acceptably sharp in the final image.
DoF ≈ 2u²Nc / f²
Depth of Field Preview
Cameras, Formats & Systems
A control that stops the lens down to the working aperture so the actual depth of field can be seen before exposure.
Depth of Field Scale
Focus & Depth of Field
m / ft
Markings on a lens barrel showing the near and far limits of sharpness for each aperture at the set focus distance.
Depth of Focus
Focus & Depth of Field
µm
The tolerance in sensor position, on the camera side of the lens, within which the image stays acceptably sharp.
≈ 2Nc
Desaturation
Colour & Colour Management
%
Reducing the intensity of colour, either globally toward monochrome or selectively within a range.
Developer
Film, Darkroom & Historic Processes
minutes at °C
The chemical solution that converts exposed silver halide crystals into metallic silver, making the latent image visible.
Diagonal Lines
Composition & Visual Design
Lines running at an angle to the frame edges, which introduce energy and a sense of movement.
Diagonal Method
Composition & Visual Design
A compositional approach placing points of interest on the 45-degree bisectors drawn from each corner of the frame.
Diffraction
Optics, Lenses & Filters
µm
The spreading of light waves as they pass the edge of an aperture, which softens the image at small f-numbers.
d = 2.44 × λ × N
Diffraction Limit
Optics, Lenses & Filters
f-stops
The aperture beyond which diffraction, rather than lens design or sensor resolution, becomes the factor limiting sharpness.
N_limit ≈ pixel pitch / 1.22λ
Diffusion Filter
Optics, Lenses & Filters
grade (1/8, 1/4, 1/2, 1)
A filter that scatters a small proportion of the light passing through it, lowering contrast and blooming highlights into a soft glow.
Diffusion Panel
Lighting & Flash
cm
A frame holding translucent fabric, used to enlarge and soften a light source placed behind it.
Digital Asset Management
Files, Metadata & Workflow
The systematic organisation, description, storage and retrieval of a body of image files.