Color sensitivity of the film
Filters available
Black-and-White Line Originals
A black-and-white line original has no middle or
intermediate tones between the lines and background.
Therefore, the best film for copying black-and-white
line originals is one with extreme contrast, such as
Kodak Kodalith film. These films produce high contrast
and extremely high density with an absence of fog,
which ensures clear lines on a dense background.
Kodalith type of films have a very limited exposure
latitude, and therefore, must be given very accurate
exposure. Underexposure produces low-contrast
negatives that result in prints having a muddy gray
background instead of a clear, crisp, white background.
Overexposure causes weak or very fine lines to fill in
and results in a less than perfect transparency of the lines
on the negative.
Typewritten material should be included in this type
of original. When an original is typed or printed on thin
white paper and on one side only, you should place
another sheet of white paper behind the original to copy
it. This increases the reflective ability of the original and
increases contrast. When the original is printed or typed
on both sides of thin white paper, place black paper
behind the original to help prevent the printing or type
on the reverse side of the original from showing through.
Colored Line Originals
In copying colored line originals to a
black-and-white reproduction, you must maintain the
high contrast between the lines and the background. This
is best achieved by using a high-contrast panchromatic
film, such as Kodak Contrast Process Pan film and a
filter. When the lines or subject is to be rendered light
against a dark background, the filter should transmit the
color of the subject and absorb the color of the
background. When the subject is to be rendered dark
against a light background, the filter should absorb the
color of the subject and pass the color of the background.
For example, a blueprint has white lines on a blue
background. Copying the blueprint with Kodalith Pan
film without a filter cannot produce maximum contrast
because the film is highly sensitive to blue light and thus
records the image of the blue background as a midtone
of gray while recording the white line image as a dense
highlight. When a red filter is used, the white lines still
record as a dense highlight on the negative, but now the
8-11
blue background records as a shadow area because the
red filter absorbs the blue light reflected from the blue
background. Thus the background reproduces darker
when a red filter is used.
Black-and-White Continuous-Tone Originals
To reproduce the tone gradation of a
continuous-tone original, you must use a long-scale
film. As discussed previously, a commercial type of
film, such as Kodak Commercial film, is recommended.
The common fault in continuous-tone original
copying is underexposure and overdevelopment. Full
exposure with restrained development is the best rule
for this type of work
Although appearing as line originals, handwritten
material, pencil drawings, and so forth, are actually
continuous-tone originals because of the midtones they
contain. These should be copied as continuous-tone
originals. Films, such as Kodak Professional Copy film
or Kodak Commercial film, are recommended.
Colored Originals
When a black-and-white reproduction of
multicolored reflection originals, such as color
photographs, oil paintings, and so forth, is to be made,
it should be copied with a moderate contrast,
panchromatic film capable of recording numerous
shades of gray. Panchromatic, long-scale film is
recommended for copying this type of color original.
Colored originals are almost limitless in their degree
of difference because of all the possible colors and hues.
Each different colored original should be copied on the
basis of what is desired in the black-and-white
reproduction.
Color Reproduction of Color Originals
Selecting a film for copying colored reflection
originals to make color reproductions is a matter of what
type of reproduction is needed-reflection or
transparency. Films, such as Kodak Vericolor III
Professional Film Type L and Type S and Vericolor
Internegative Film, can be used to produce color
reflection copies. Color transparency film must be used
to produce color transparencies from reflection
originals. Some films have a different recommended
ISO rating when used with tungsten or daylight light
sources. Be sure to consult the data sheet supplied with
the film or the Photo-Lab Index to determine the proper
ISO setting.

Basic Photography Course












Privacy Policy