negatives. The following basic rule applies:
Film development time controls negative contrast.
In short, increasing film developing time produces negatives with greater contrast,
and reducing developing time produces negatives with less contrast. Understanding
this basic rule allows you to easily fine-tune the contrast of your
negative. Let’s say normal development time with your film and developer is 10
minutes. If you are photographing when the light is a little flat and dull, you
can increase negative contrast slightly by developing your film for 12 minutes
instead; if you are photographing on a somewhat bright, sunny day, you can
decrease negative contrast slightly by developing your film for 9 minutes.
One of the best uses for this technique occurs when you are photographing
indoors under low light. Often your negatives in such situations will be a little
light and print flat and gray. If you make a practice of developing film shot indoors
just a little longer than normal (about 10–20 percent), your negatives
will have more contrast and be easier to print.
Deciding how much to increase or decrease developing time can be tricky, as it
varies from one lighting situation to another—and also according to the type of
film and film developer you use. Here are some general guidelines you can use:
For more negative contrast, increase normal developing time by
10–25 percent or more.
For less negative contrast, decrease normal developing time by
10–15 percent or more.
In many cases, the subject lighting varies from one exposure to another on a
roll of film. Because adjusting film development affects all the negatives on your
roll, you may have to base your developing time on what you consider the most
important pictures on the roll. If you have 15 shots taken in flat (low-contrast)
light that you think will be your best images, you might want to increase the film
developing time to make sure you have the optimal negatives for those pictures.
If you do so, however, you may be sacrificing the quality of some of the other
pictures on the roll.
Pushing Film. The term pushing film means increasing the film development
time. Sometimes you’ll want to do this to slightly punch up the negative contrast,
as described above. But you might also want to push film when you are
working in low-light conditions without a flash or other artificial lighting. In
such situations, your film speed may not be high enough to capture the available
light, even with your lens open to its maximum aperture and your shutter
speed set as low as possible for you to handhold the camera. Or you may not
be able to use a high enough shutter speed with the available light to freeze the
action at a sporting event. Exposure and Development
Although this chapter is about film development,
don’t underestimate the importance of film exposure
in producing a good negative. Both exposure
and development time are critical in determining the
overall density of your negative. The density of the
shadow areas of your negative is primarily determined
by film exposure, and the density of the highlight
areas is primarily determined by development.
Thus, this commonly stated rule of thumb:
Expose for the shadows;
develop for the highlights.
Here’s how it works. In your subject, the shadows
are the darkest areas. This means they reflect the
least amount of light back to the camera. If you give
film too little exposure, the developed shadows will
not render with enough density to register good textured
detail. Changing development cannot create
subject details where there are none on the film; it
can only modify the contrast of existing detail. So,
to produce a negative with good shadow density,
you must give the film adequate exposure.
Film develops in proportion to exposure, which
means that the development time does not have a
significant impact on the shadow areas. Shadow
areas are the areas that received the least exposure;
they do not take much time to form on the negative.
For instance, if the normal developing time for a roll
of film is 10 minutes, then the shadow density fully
forms in about half that time—possibly 5 minutes.
The remaining 5 minutes of development mostly
affects the highlight areas.
The highlight areas are the lightest areas of your
subject, which are the areas that reflect the most
light back to the film. This means they have far
more exposed silver particles needing development
than shadow areas. Thus, the longer you develop
your film, the greater the highlight density in the developed
negative. If you develop your film for 15
minutes rather than 10, the highlights get significantly
denser but the shadows do not. As the difference
between the shadow and highlight density becomes
greater, so does the negative contrast, meaning
that increasing film development time increases negative
contrast.
The opposite happens when you reduce the development
time, from 10 minutes to, say, 8 minutes.
The highlight areas render with less density and the
shadow density stays about the same. This minimizes
the difference between the shadows and highlights,
resulting in less negative contrast. Thus,
decreasing film development time decreases negative
contrast. Suppose the meter indicates that you don’t have enough light to make a good
exposure, even with your lens at its largest opening and your shutter speed at a
slow setting, perhaps f/2 at 1/30. Try resetting your light meter for a higher film
speed; for example, rate ISO 400 film at 800 or 1600. Setting the higher film
speed signals the meter that the film is faster (more sensitive to light) than it
really is, and therefore that it needs less light for adequate exposure. For instance,
set at 1600 the meter may indicate that settings of f/2 at 1/30 will provide
enough light; if so, take the picture, then “push” the film—develop it for longer
than the normal amount of time suggested by the manufacturer.
Pushing is especially useful when you are photographing with a zoom lens
because most zooms don’t have a very large maximum aperture. For instance,
a lens with a maximum aperture of f/4 probably won’t allow enough light through for photographing in low light without a flash or other accessory lighting.
(That’s why a normal fixed-focal-length lens that opens to a large f-stop,
usually f/2 or so, works better than a zoom for photographing in low light.)
Also, consider using an extra-high-speed film in low light, rather than pushing
development. ISO 1600 or 3200 film is fast enough to capture light in most
dark scenes. However, under very dim light, you may need to push even extrahigh-
Increasing film speed and pushing development can be very helpful in lowlight
conditions, but it is not a cure-all. The film doesn’t suddenly become faster
just because you are rating it at a higher speed. What you are doing is underexposing
the film—giving it less light than it really needs—and pushing development
for increased contrast to compensate. This allows you to make a decent
print in a difficult situation.
The amount of increased development you will need can vary widely, depending
on the increase in film speed you want, the type of film, and the type
of developer. These are general guidelines for pushing ISO 400 film:
Pushed speed means you are therefore
rating . . . underexposing by . . . overdevelop by . . .
800 1 stop 35–50 percent
1600 2 stops 75–100 percent
Thus, if your meter indicates an exposure of f/2 at 1/15 with ISO 400 film,
you can set your ISO at 800. Now the meter will recommend 1 stop less light—
perhaps, f/2 at 1/30 (or the equivalent)—and you must increase development to
compensate—for example, develop for 131⁄2 to 15 minutes instead of the normal
time, say, 10 minutes. Or, you can set your ISO at 1600 and use 2 stops less
light—perhaps, f/2 at 1/60 or f/2.8 at 1/30—and develop for 171⁄2 to 20 minutes
instead of 10 minutes.
You can also use the same guidelines when pushing with a different-speed
film, for example, rating ISO 1600 film at 3200 (a 1-stop push) and overdeveloping
by 35–50 percent, or rating it at 6400 (a 2-stop push) and overdeveloping
by 75–100 percent.
Note that there are extra-active high-speed film developers specifically made
for pushing film. Normal developing times with these developers are like pushed
times with other developers. Follow the instructions on the developer packaging
for details rather than using the guidelines above for developing times.
Pushing film is a good solution when you are working in low-light conditions,
but it does have some disadvantages.
Loss of shadow detail. Shadow details in the negative are determined by film
exposure, and pushing means you have underexposed the film.
High contrast. The increase in development causes an increase in contrast.
This is usually a good thing for photographing on a foggy day but may not
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