PHOTOGRAPHY GLOSSARY (E-G)
Glossary - E
E6 - Kodak's standard chemical process for developing
Ektachrome or compatible slide films.
Easel - device to hold photographic paper flat during
exposure, usually equipped with an adjustable metal mask for framing.
Eberhard effect - border effect occurring in a developed
image. It appears as a dense line along an edge of high density
and as a light line along an edge of low density. It occurs most
often in plates developed flat in solution that is not sufficiently
agitated. The effect was described by Gistav Eberhard in 1926.
Edge numbers - reference numbers printed by light
at regular intervals along the edge of 35mm and roll films during
Effective aperture - diameter of the bundle of light
rays striking the first lens element that actually pass through
the lens at any given diaphragm setting.
EIS - Electronic Image Stabilizer. A feature that
minimizes effect of camera shake.
Electroluminescence - conversion of electric energy
directly into visible light.
Electronic flash - artificial lighting produced
by an electronic discharge in a gas filled tube. A single tube
can produce a large number of flashes.
Electronic shutter - shutter system timed by electronic
rather than mechanical means.
Electrophotography - creation of images by alteration
to the electrical properties of the sensitive material as a result
of the action of light.
Element - single lens shaped piece of glass that
forms part of a compound lens system.
Elon - another term for Methylaminophenol sulfate.
It is more commonly known as metol.
Emulsion - light sensitive
material which consists of a suspension of silver halides in gelatin.
Emulsion side - side of the film coated with emulsion.
Endoscope - optical device allowing the viewing
and photography of small inaccessible subjects.
Enhanced back printing - Advanced Photo System feature
available in some cameras that enables users to encode detailed
information at the time of picture-taking.
Enlargement - term used to describe a print larger
than the negative used to produce it.
Enlargement ratio - ratio denoting the amount of
linear (not area) enlargement between a print and the negative
from which it is made.
Enlarger - apparatus for producing prints by projecting
a negative or transparency on sensitive paper.
Enprint - small enlarged print, with dimensions
of a fixed ration, produced commercially in an automatic printer.
Usually 3 ½" wide.
Entrance pupil - size of the beam of light which,
entering the elements of a compound lens that are in front of
the aperture, completely fills the iris diaphragm.
Equivalent focal length - distance in a lens between
the front nodal
point and the focal
plane when the lens is set to focus a subject at infinity.
In a telephoto lens the equivalent focal length is shorter than
the back focus. The reverse is true in a wide angle lens.
Etch - process of removing small imperfections in
a print or negative by scraping away part of the emulsion.
Etching - dissolving away selected areas of a surface
while shielding the other portions with a resistant. The process
is used as a creative drawing medium as well as for making half-tone
plates on copper or zinc.
Ever-ready case - camera case that can be opened,
allowing the camera to be used without removing it. A front flap
hinges down to uncover the lens, viewfinder and camera controls.
Everset shutter - simple camera shutter mechanism
on which a single depression of the release both tensions and
fires the shutter.
Exit pupil - image of the iris diaphragm
formed on the back surface of a compound lens by the elements
behind the aperture.
Expiry date - date stamp on most film boxes indicating
the useful life of the material in terms of maintaining its published
speed and contrast.
Exposure - product of the intensity of light and
the time the light is allowed to act on the emulsion
(I x T = E).
Exposure index - see Speed.
Exposure latitude - amount by which it is possible
to over or underexpose a light sensitive material and, with standard
processing, still produce acceptable results.
Exposure meter - instrument
for measuring the amount of light falling on or being reflected
by a subject.
Exposure value (EV) -
scale of values used to indicate the sensitivity range of a TTL
or off-camera meter system within which accurate exposure measurement
Extension bellows - device used to provide the additional
separation between lens and film required for close-up photography.
Extension tubes - metal or plastic tubes used on
small format cameras, to extend lens-to-film distance, enabling
magnification greater than 1x.
Extinction meter - early type of exposure calculator.
Glossary - F
Factor - number that tells how many times exposure
must be increased in order to compensate from loss of light.
Fahrenheit scale - scale of temperature named after
its German originator, G. D. Fahrenheit. On this scale, the freezing
point of water is 32° F, and the boiling point of water is 212°
False attachment - part of one object seen behind
another so that lines, shapes or tones seem to join up. A composition
device used in various ways to produce images in which foreground
and background objects appear to occupy the same plane.
Farmer's reducer - used for bleaching negatives
Farraday shutter - high-speed shutter using a pair
of crossed polarizers, between which is a glass block within a
coil. When a voltage passes through the coil, the plane of polarization
changes, allowing light to pass through the second polarizer.
Fast film - film which has an emulsion that is very
sensitive to light. These films have high ISO ratings.
Fast lens - lens with a wide maximum aperture (low
Ferric chloride - bleaching solution used on negative
Ferrotype process - method
of creating direct positive images with dark enameled metal plates
as a base. Also known as the tin-type process.
Fiber based paper - photographic paper without a
resin coating. Processing times are longer than for other papers,
but the paper is more archivally permanent.
Field camera - sheet film camera suitable for use
in location work.
Fill-in - light used to
illuminate the shadow areas of a scene.
Fill light - source of illumination that lightens
shadows. See Fill-in.
Film - photographic material consisting of a thin
transparent plastic base coated with a light sensitive emulsion.
Film characteristic curve - describes a graphical
relationship between the logarithm of the exposure value (horizontal
axis) and density (vertical axis) of film. Each brand of film
exhibits a different characteristic curve.
Film clips - metal or plastic clips used to prevent
the curling of a length of drying film.
Film holder - light tight container to hold sheet
Film pack - container holding several sheets of
film, so devised that when fitted to the camera the photographer
can pull a tab to remove an exposed sheet and replace it with
another. Film packs are typical with Polaroid film.
Film plane - plane at
the back of the camera across which the film lies.
Film speed - see Speed.
Filter factor - number by which an unfiltered exposure
reading must be multiplied to give the same effective exposure
through the filter. This compensates for the absorption of light
by the filter. This process is unnecessary with TTL metering systems
as long as the filter is attached during the metering process.
Filters - colored glass, gelatin or plastic disks,
which modify the light passing through them, mainly in terms of
color content. They can be used at the camera or printing stages.
Finality development - prolonged development, reducing
silver halides affected by light to silver until no further image
density improvement occurs.
Finder - abbreviation for viewfinder.
Fine grain developers - film developers which help
to keep grain size in the photographic image to a minimum.
Fisheye lens - extreme wide-angle lens with an angle
of view exceeding 100° and sometimes in excess of 180°. Depth
of field is practically infinite and focusing is not required.
Fixation - chemical bath
which converts unused halides to a soluble silver complex in both
negatives and prints, making the image stable in white light.
Fixed focal length - camera system whose lens cannot
be interchanged for a lens of different focal length.
Fixed focus - lens camera system that has no method
of focusing on a fixed point, usually at the hyperfocal distance.
Fixer - chemical solution used for fixation.
Flare - non-image forming light scattered by the
lens or reflected from the camera interior.
Flash - artificial light source giving brief but
very bright illumination. It is produced by a combination of certain
gases within a transparent tube. There are two types; electronic,
which may be used repeatedly, and expendable in which the bulb
can be used only once.
Flash bulb - replaceable bulb for use in expendable
flash units. A glass bulb contains a pyrotechnic wire or paste
which burns out in a brilliant flash when a low voltage firing
current is applied.
Flash cube - obsolete bulb containing four small
flash bulbs built into a single unit.
Flash factor - number which provides a guide to
correct exposure when using flash. See also Guide
Flashing - briefly and evenly exposing photographic
materials to white light.Often used to lower contrast of printing
paper, when the flashing exposure is made in addition to the regular
Flash powder - chemical powder consisting of a mixture
of metallic magnesium and an oxidizing agent. Ignited by heat
to produce a brilliant flash of light.
Flash synchronization - method of synchronizing
flash light duration with maximum shutter opening. There are usually
two settings on a camera, X and M. X is the setting used for electronic
flash. M is for most expendable types of flash (bulbs) which require
a delay in shutter opening.
Flat - used to describe a negative or print with
very low contrast.
Flat-bed camera - camera designed for copying artwork
and documents. Mounted on a vertical column, like an enlarger,
allowing the photographer to accommodate different documents or
artwork for duplication.
Flat gradation - subjective term used to describe
Flat lighting - lighting that produces very little
contrast or modeling on the subject and a minimum of shadows.
Floating elements - one or more elements in a lens
which adjust position relative to other components during focusing
or zooming. Used to maintain correction of lens aberrations at
Floodlight - artificial light source with a dish
shaped reflector and a 125-500+ watt tungsten filament lamp producing
evenly spread illumination over the subject.
Fluorescent whites - brilliant highlights produced
by applying a fluorescent agent to a printing paper base. The
print can also be treated after washing with a fluorescent whitener
or dye solution.
f numbers -e numbers on
the lens barrel indicating the size of the aperture
relative to the focal length of the lens. f numbers are calculated
by dividing the focal length of the lens by the effective diameter
of the aperture.
Focal length - distance between the rear nodal
point of the lens and the focal plane, when the focus is at
Focal plane - imaginary
line perpendicular to the optical
axis which passes through the focal
point. It forms the plane of sharp focus when the lens is
set at infinity
Focal plane shutter - shutter which lies just in
front of the focal plane. Light sensitive film positioned at the
focal plane is progressively exposed as the shutter blinds move
Focal point - point of
light on the optical
axis where all rays of light from a given subject meet at
a common point of sharp focus.
Focus - position in which rays of light from a lens
converge to form a sharp image.
Focusing - system of moving the lens in relation
to the image
plane so as to obtain the required degree of sharpness of
Focusing cloth - dark cloth used in view camera
Focusing hood - light proof cowl used on TLR and
most roll film SLR cameras to prevent extraneous light falling
on the focusing screen.
Focusing magnifier - device to magnify the optical
image and aid visual focusing.
Focusing scale - scale of distances marked on a
lens focusing ring.
Focusing screen - ground glass screen fixed to the
camera at the image-forming plane, enabling the image to be viewed
Focus range - range within which a camera is able
to focus on the selected picture subject.
Fogging (Fog) - produces
an overall veil of density on a negative or print, which does
not form part of the image. It can be achieved by chemicals or
exposing the sensitive material to light.
Fog level - density formed
in unexposed areas of film or paper during processing.
Foreground - area in an image closer than the main
Format - size of negative paper or camera viewing
Frame 1. single exposure on a roll of film. 2.
viewfinder image boundary.
3. Decorative border applied to finished, mounted prints.
Frames per second (fps) - used to describe how many
frames can a motor drive or winder handle automatically.
Free working distance - distance between the front
of the lens and the subject.
Fresnel lens - condenser lens used on a spotlight
to gather together the rays of light coming from a source and
direct them into a narrow beam.
Fresnel magnifier - condenser lens used at the center
of some ground glass viewing screens to aid focusing.
Frilling - wrinkling and separation of the emulsion
along the edges of its support material.
Front curtain synchronization - when the flash fires
an instant after the front curtain of a focal plane shutter has
completed its travel across the film
Front element focusing - system of lens focusing
in which only the front component of a compound lens moves backward
and forward to adjust focus.
Front projection - method of projection which allows
you to combine a figure in a studio with a previously photographed
background scene. The image is projected from the camera position
onto a special reflective background screen.
F stop - number that equals the focal length of
the lens divided by the diameter of the aperture.
Full scale print - print having a wide range of
Futurism - art movement started in Italy c. 1910,
characterized by an aggressive rejection of tradition, and the
representation of the dynamic movement of machinery.
Glossary - G
Galvanography - technique of electroplating a gelatin
relief image created photographically to produce a photomechanical
Gamma - measurement used
in sensitometry to describe the angle made between the straight
line portion of the characteristic
curve of the photograph emulsion and the base of the graph.
The gamma is the tangent of the angle so formed.
G curve - average gradient of a characteristic curve,
describing similar characteristics to gamma, but measuring the
slope from a line joining the lower and upper limits of the curve
actually used in practice.
Gelatin - natural protein
used as a transparent medium to hold light sensitive silver halide
crystals in suspension, binding them to the printing paper or
film, yet swelling to allow entry of processing solutions.
Gelatin filters - filters cut from dyed gelatin
sheets and held in front of the lens or studio light.
Gelatin sugar process - daylight printing process
using paper with a sugar and dichromate coating, which hardens
on exposure to light.
Ghost images - bright spots of light, often taking
the shape of the aperture, which appear in the camera viewfinder
or in the final photograph when a lens is pointed at a bright
light like the sun. Ghost images have been almost eliminated through
the use of multi layer coatings of the lens elements.
Glaze - glossy surface produced on some (non resin
coated) printing papers. It is achieved by placing a wet print
to to a heated drum or clean polished surface. Glazed print produce
denser medium blacks than their matte counterparts.
Glazer - machine on which wet fiber base prints
are placed face down in contact with a polished surface, such
a chromed steel, and held by tension. The surface is then heated
to dry the print.
Glossy paper - printing paper with a smooth shiny
surface finish to give maximum detail and tonal range.
Gold chloride - soluble chemical used in gold toners.
Gold mean - compositional technique used to determine
the "ideal" position of the main subject in the frame.
It is based on creating a rectangle from a square. A line drawn
from the center of one side of the square to the opposite corner
becomes the radius of an arc. The side of the square is then protracted
until it meets the arc, and from this point a rectangle is constructed.
The side of the square which remains in the rectangle indicates
the point at which the subject should be placed.
GOST - arithmetical system of rating film speed
used in Soviet bloc countries.
Graduated filter - filter with a colored section,
which gradually reduces in density toward the center of the filter.
The rest of the filter is clear. Also referred to as a Graduated
Gradation - tonal contrast range of an image.
Grade - system of terms and numbers used to denote
the contrast characteristics of black and white printing papers.
Graduate - vessel used for measuring liquids.
Grain - clumps of silver-halide grains in film and
paper that constitute the image. These grains are produced both
in the exposure process (film grain) and in the development process
(paper grain). Unlike film, the grain in printing paper is largely
responsible for the image tone.
Graininess - clumps of silver halide crystals in
the emulsion which are visible to the human eye because of spaces
between the crystals.
Grains - exposed and developed silver halides which
have formed black metallic silver grains, producing the visible
Granularity - objective term describing the amount
that silver halide grains have clumped together within the emulsion.
Gray card - card with an 18 percent gray tint (reflectance)
used to determine exposure by taking a meter reading from subject
light reflected by the card.
Ground glass screen - translucent glass sheet used
for viewing and focusing the image on all large format and some
Guide number - term sometimes
used to describe a flash factor, which provides a guide to correct
exposure when using flash.
Gum arabic - water soluble gum obtained from the
Acacia tree and used in coatings of a number of photographic processes.
Gum bichromate - contact
printing process once very popular for the manipulative, impressionistic
effects it makes possible. Drawing paper is coated with a mixture
of gum, potassium bichromate and a pigment of any chosen color.
This is then exposed to light behind a negative. Also known as
the photo aquatint
Gum platinum process - combination of gum and platinum
Gyroscopic camera mount - device employing a gyroscope
to help stabilize hand held cameras subject to movement or vibration
from outside sources.