Film Latitude

Accurate exposure is just as important with color reversal films as it is with digital.
Reversal films also have little exposure latitude—that is, they do not tolerate over- or
underexposure (see Figure 5.3). Colors in a transparency begin to look too dark with
as little as one-half stop underexposure. Because there is little tolerance for overexposure,
colors look pale and bleached out.
Color negative film has much more exposure latitude than reversal film. You will
have a printable negative with as much as one stop underexposure or three stops of
overexposure. However, the best results always come from correctly exposed film.
In contrasting lighting, color reversal film and most digital cameras are not able to
record the full range of brightness. In scenes with very bright highlights (such as
snow or sand) and very dark shadows, the scene’s brightness range (the overall contrast)
is greater than the exposure range of the film or sensor.
If the shadows are correctly exposed the lightest areas will be blank white. If the
light areas are well exposed, the shadows will be featureless black. You can compromise
and expose for the most important part of the scene. You can also bracket
(shoot additional pictures with different exposures). The best solution to greatly contrasting
scenes is to use an electronic flash or a large reflector to add light to the
shadow areas, thus reducing the scene’s contrast
Low-contrast lighting has a smaller tonal range and thus allows film and digital
cameras to easily capture details in both the bright and dark areas. In addition,
such lighting is more forgiving of exposure errors than greatly contrasted lighting.
Fill-in flash can also lighten contrasted shadows.
Even though negative film is more forgiving, remember that you will lose additional
detail when you scan in an image. Scanning an overexposed or underexposed negative
results in loss of detail in shadows and highlights. This situation is even worse
when you scan in prints!