METRIC SYSTEM–A decimal system of measure-
ment based on the meter as the unit of length, the
kilogram as the unit of mass, and the liter as the unit
of capacity.
MICRON–A unit of length in the metric system equal
to 0.001 millimeter.
MILLILITER–A unit of volume in the metric system.
1 mL = 0.03381 fl oz
29.57 mL= 1 fl oz
3785 mL= 1 gal
MILLIMETER–A unit of length measuring 0.001 of a
meter; 25.4 millimeters equal approximately 1 inch.
MILLIMICRON –A unit of length in the metric system
equal to 0.001 micron. It is also equivalent to 10
angstroms.
MODELING–Photographic term for the feeling of
“plasticity” engendered by a photograph or the
three-dimensional effect produced in a photograph
by effective camera work and lighting. (PIA)
MOTTLE–A photographic defect characterized by
nonuniform density differences; usually in the
pattern of tiny, circular areas.
MOUNT, BAYONET–A means of quickly attaching or
removing a lens or filter by turning through only part
of a revolution.
MOUNTING–The process of fastening a photographic
print to a support.
NEAR POINT–The nearest object to the camera that is
still acceptably sharp when the camera is focused
for a given distance.
NEGATIVE, BLACK-AND-WHITE–A
photo-
graphic image on film or paper in which light tones
are rendered dark and dark tones appear light.
NEGATIVE, COLOR–A negative record of the color
values of the original object. Not only are light
values represented by negative densities but colors
are represented negatively by their color
complements. (PIA)
NEUTRAL–Hueless or achromatic color; gray. Chem-
ically, a solution that is neither acid nor alkaline.
(PIA)
NOISE–Unwanted sounds or electrical interference in
an audio or video signal. In the audio track, there is
a hiss or humming sound. In the video picture the
interference appears as “snow.”
NORMAL –Sometimes called the perpendicular. An
imaginary line forming right angles with a surface
or other lines. It is used as a basis for determining
angles of incidence, reflection, and refraction.
NOTCHING CODE–One or more notches of
characteristic shape placed by the manufacturer in
one edge of a sheet of photographic film to identify
the emulsion side and the emulsion type. (PIA)
NTSC–National Television Standards Committee. U.S.
standards for television or video signal
broadcasting. Also known as the composite signal
(Y/C).
OPACITY –(l) The ability of an object to absorb light.
(2) Photographic term for the light-stopping power
of the silver deposit in negative images. Opacity
= 100/Transmittance in percent.
OPAQUING–All handwork on a negative to remove
spots or unwanted images.
OPEN FLASH–A method of taking photoflash pictures
in which the camera shutter is held open during the
flash and then closed.
OPTICAL CENTER–The point, generally within a
lens but sometimes exterior to it, at which the optical
axis and all chief rays of oblique ray bundles
intersect.
ORIGINAL–Material from which copies are made,
such as handwritten copy, typed copy, printed
matter, tracings, drawings, and photographs.
(IABPAI)
OVERCOATING –A thin layer of clear or dyed gelatin
sometimes applied on top of the emulsion surface
of a film to act as a filter layer or to protect the
emulsion from abrasion during exposure and
processing.
OVERDEVELOP –To permit a photographic image to
be developed too much because of one or more of
the following factors: (1) excessive time, (2) ex-
cessive temperature, (3) overstrength of developer
solution, and (4) excessive agitation.
OVEREXPOSE–To permit too much exposure of a
photographic emulsion. This may be caused by
(1) too brilliant light, (2) too large an aperture, or
(3) too much time.
OVEREXPOSURE–A photographic exposure that
exceeds the maximum latitude of the sensitized
materials.
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