Basic Photography Course

Table 3-1.Parallel Filter Bars

Filter Color and No.

Deep Red

Bluish Green

Red

Bluish Green

Light Red

23A

Cyan

Orange

Cyan

Deep Yellow

Blue

Yellow

Deep Blue

47B

Yellowish Green

Violet

34A

Yellowish Green

Violet

34A

Green

Magenta

Green

Magenta

Use the parallel filter bars to choose contrast filters

for black-and-white photography. Adjacent filters

lighten colors next to them. Opposite filters darken
colors in the print; for example, a yellowish green No.

11 filter lightens subjects that are yellowish green or

yellow and darkens subjects that are violet. A No. 44
cyan filter lightens blue and blue-green and darkens
light red and orange.

Correction Filters

Although panchromatic film responds to all the

colors the eye can see, it does not reproduce tones of red,
green, and blue objects in the same relative values as the
eye sees them. The human eye is much more sensitive
to green than it is to blue and red, and these colors look
darker to the eye than green (fig. 3-2). Panchromatic
film is more sensitive to blue and violet and looks lighter
than green in a black-and-white print. This high
sensitivity to blue and violet causes an overexposure to
the film of blue objects as compared to green objects.
This overexposure causes a dense negative image that

Figure 3-2.Color sensitivity of the average human eye.

results in a light print image (fig. 3-3).

A No. 8 yellow filter with panchromatic film helps

to reproduce colors of a daylight scene with the same
brightness relationship as seen by the human eye.

When using tungsten lighting, you can use a

yellowish green No. 11 filter to reproduce the natural
brightness relationship with panchromatic film. The
yellow in the filter absorbs the ultraviolet radiation and
some of the blue light, while the green in the filter

absorbs some of the red light.

Figure 3-3.Color sensitivity of panchromatic film.

3-3

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Basic Photography Course

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