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A grey card is an indispensable part of the serious
photographer's tool-kit. It delivers the full range of vital functions,
including exposure measurement, contrast measurement, colour balancing
and the setting of white balance.
The Douglas Grey Card combines trusted scientific principles with
new materials to provide better colour balancing of digital and
conventional materials, for the fullest range of natural and artificial
light conditions.
The card reflects the same proportion of all colours of light falling
on it, including ultra-violet and the limit of visible red. It has
a more neutral reflectance than rival products under the widest
range of sources of illumination, including tungsten, daylight,
flash and warm fluorescent tubes.
Manufactured in a tough synthetic it can be written on with a Chinagraph
pencil or marker designed for wall planners, and cleaned off with
a mild detergent or a spray cleaner designed for cleaning TV or
computer screens.
Folded, the Douglas Grey Card is just under
A5 size (9" x
7" / 225mm x 175mm) to fit snugly in your camera bag. Fully
opened it is large enough to fill a 35mm camera viewfinder at 50
cm/1 ft 6 ins with a 50mm lens. The grey side has a reflectance
value of 18% which represents a middle value of 5 in the Munsell
system of colour notation and the middle tone (Zone V in the Ansel
Adams Zone System) used for exposure determination, half way between
pure black and pure white. The grey side is used for exposure measurement
for either digital, negative or colour transparency material, for
colour balancing and for the setting of white balance. The white
side is used for measuring lighting contrast and as a superior
method of exposure measurement for colour transparency material. |