PHOTOGRAPHY GLOSSARY (V-Z)
Glossary - V
Vacuum back is a camera back with a perforated plate
through which air is drawn by a pump. A sheet of film is therefore
sucked flat against the plate and held firmly during exposure.
Used for special large format cameras such as copying devices
where dimensional accuracy is critical.
Vacuum easel is a compact printing frame which ensures
firm contact between the film and paper by excluding air between
the surfaces. Some types are used to hold the paper flat on the
enlarger baseboard when enlarging.
Vanishing point is the point at which parallel lines,
viewed obliquely, appear to converge in the distance.
Vapor discharge lamp is a lamp in which electrical
current passes through a vapor or gas rather than through a wire
filament, thus producing illumination.
Variable contrast paper is a printing paper in which
the contrast can be varied depending on the color of the printing
light. This can be altered by using different color filters.
Variable focus lens is a lens whose focal length
can be continually varied within a given range. Also known as
a zoom lens.
Veil is a uniformly distributed silver deposit in
a photographic image, not forming part of the image itself. Also
known as fog.
Video still camera is a camera using an electronic
charge coupled device instead of film.
View camera is a large format
camera which has a ground glass screen at the image plane for
viewing and focusing.
Viewfinder is a system used
for composing and sometimes focusing the subject. There are several
types: direct vision, optical, ground glass or reflex.
Viewpoint is the position of the camera in relation
to the subject.
Vignetting is a printing technique where the edges
of the picture are gradually faded out to black or white. It also
refers to a fall off in illumination at the edge of an image,
such as may be caused by a lens
hood or similar attachment partially blocking the field of
view of the lens.
Vinyl film is an emulsion coating on a polyvinyl
chloride acetate base, with less shrinkage than conventional film
Viscose sponge is a synthetic sponge used to wipe
surplus water off films before they are hung up to dry.
Viscous processing is a process using chemicals
carried in sticky semifluid substances instead of normal liquids.
Used for instant picture processing.
Volt is a unit of electrical potential difference
and electromotive force.
Voltage stabilizer is a transformer used to produce
a steady output voltage despite fluctuations of input voltage.
Vortograph is an abstract photograph made with a
simple kaleidoscopic apparatus, first used by Alvin Langdon Coburn
Glossary - W
Warm colors are any colors which, by association,
suggest warmth, such as red, orange and yellow.
Warm tone developer is a developer
producing image colors in chlorobromide
papers ranging from warm black to reddish brown, according
Washing is the final part of the processing cycle,
which removes residual chemicals and soluble silver complexes
from the emulsion.
Water bath are large water filled containers used
to maintain processing trays, tanks or chemicals at the correct
Waterproof paper is another term for Resin-coated
Water softeners are used to eliminate most of the
minerals and slats found in hard water.
Watkins factor is an old system of development control,
based on observation of the processing image under safe lights.
Watt is a unit of power in electricity.
Watt-second is an alternative unit of energy, equal
to the joule.
Wavelength describes the distance
from wave-crest to wave-crest between two corresponding waves
of light in the electro-magnetic spectrum. Wavelengths are measured
(nm) and Angstrom units (A).
Waxed paper process is an early form of photography.
A variation on the calotype process.
Weak is a negative or print which is low in contrast
Wedge spectrogram is an indication of the spectral
sensitivity of a sensitized material by exposing it to a spectrum
of light through a graduated gray wedge.
Wet collodion is a much improved
calotype developed by Frederick Scott Archer. A sensitized glass
plate was dipped into a bath of silver nitrate and exposed while
still wet. The improved speed made much shorter exposures possible.
Wet processing is processing by the application
of chemicals in fluid form. The traditional method of photographic
Wetting agents are chemicals which, when used in
minute quantities, reduce the surface tension of water. They are
usually added to the final wash of films and plates to improve
White Light see White
White light control is the level or switch on a
color enlarger which removes all color filtration and returns
it when required.
White light spectrum is the
between 400-700 nanometers.
Also referred to as the visible spectrum.
Whole plate is a negative or print format measuring
6 ½ x 8 ½ inches.
Wide-angle lens is a lens with wide covering power.
It has a focal length which is less than the diagonal of the film
format with which it is being used.
Wide-angle rack is an additional focusing rack used
on large format cameras.
Wide area AF means the autofocus detection area
is wider than normal. Making it easier to photograph moving subjects.
Wood print is a print made on a wood surface which
has been photochemically prepared.
Working aperture is the widest aperture at which
an acceptable image can be achieved.
Working solution is a liquid chemical that has been
mixed and diluted for use.
Glossary - X
Xenon is a rare gas sometimes used with electronic
flash tubes and enclosed arc light sources.
Xerography is a photographic process which uses
an electrically charged metal plate. On exposure to light the
electrical charge is destroyed, leaving a latent image in which
shadows are represented by charged areas. A powdered pigment dusted
over the plate is attracted to the charged areas, producing a
Xography is a system of photography which produces
prints and transparencies with a three-dimensional effect. A cylindrically
embossed lenticular screen is placed in contact with the film
and a shutter behind the lens is arranged to scan the subject
X ray are electromagnetic radiations
beyond ultraviolet which, when passed through a solid object and
allowed to act upon a sensitive emulsion, form a shadow image
of the internal structure of the object.
X ray film is spectral sheet film for radiography,
having a thick emulsion coated on both sides of the support to
increase the absorption of X rays.
X setting (X sync) is the setting that causes the
flash to burst in synchronization with the shutter. For some manual
cameras, the X synch speed refers to the maximum speed that the
camera can synchronize with the flash.
Photo Glossary - Y
Yellow is the color formed by mixing red and green
light. Yellow is complimentary to blue, and is one of the three
colors used in subtractive color synthesis.
Glossary - Z
Zirconium lamp is an arc lamp used in powerful enlarges
Zoetrope is an early device for creating illusion
of continuous motion. A sequence of still pictures was viewed
so quickly through slits in a rotating drum, that the images appeared
Zone focusing is a method of focusing the lens so
that the depth of field extends over a preselected range of distances.
Zone system is the method of determining exposure
and development required for individual scenes, invented by Ansel
Adams. It is based on analysis of subject luminosities in terms
of ten gray tones, labeled zones 0 through X and previsualizing
them as print densities. By measuring each subject luminance with
a hand meter it is possible to determine how much the range of
values must be contracted or expanded by negative development
control to give the required values in the print.
Zoom lens is a lens which is constructed to allow
continuously variable focal length within a specific range. The
effective aperture and focus settings remain unchanged throughout