THE PHOTOGRAPHIC EYE

crystals that received no light will not
be affected. Those that received a little
light will become increasingly dark
as the developing continues, producing
a lighter print. If the developing
goes on too long, the result will be a
print in which the contrast will be extremely
high and everything will look
overexposed.
Shortening the developing time will
reduce contrast, since even the
crystals that received the most light
will only have time to become gray.
Stop Bath: Since virtually all
developers only work well in an
alkaline (non-acidic) solution, the
developing process will be halted if
the solution becomes acidic. That's
precisely what stop bath does.
Stop bath is simply diluted acetic
acid. When the film, with developer
on its surface, is immersed in the stop
bath, this acid halts the development
process. If you were to rinse off the
stop bath and place the film back in
the developer, the development process
would continue.
Indicator stop bath also contains
a dye that turns purple when the acid
is no longer active enough to be useful.
If you are using an indicator stop
bath, you can safely recycle it until
the dye begins to change color (to a
brownish gray). Most photographers,
however, simply discard it after each
use when processing film. (The indicator
dye is more helpful when
you're processing prints.)
Fixer: "Fixing" film does two
things: It dissolves all the silver
crystals that have not been activated
by the developer, and it hardens the
emulsion. In essence, -it "locks" the
image.
There are two basic kinds of fixer:
the regular variety (sodium thiosulphate)
and "rapid fixer" (aluminum
thiosulphate), which simply reacts
228 The Photographic Eye
more quickly. The key differences
between the two is speed and, of
course, price.
Wash: Film must be thoroughly
washed. Chemical traces left on the
film by improper washing will interfere
with the quality of your prints
and may damage the negative as well.
The quality of the water you use is
also important. Most water that is
safe to drink should be fine for
washing films (as well as for diluting
chemicals and washing prints).
If, however, you repeatedly
discover streaks, smears, speckles or
other curiosities on the film's surface,
try washing a few rolls in bottled or
distilled water. If the curiosities go
away, then your tap water is probably
the problem. It's likely to be fine for
diluting chemicals and may be okay
for washing prints, but keep a bottle
of "good" water on hand for washing
film.
Wetting Agent: A final step that
is highly recommended, but not
strictly essential, is coating the film
with a wetting agent. The wetting
agent covers the film with a slippery
surface, so any impurities in the
water will tend to slide off rather than
stick. If you don't use a wetting
agent, there's always a risk that
something (mineral deposits, dust in
the air, or even just bubbles in the
water) will leave a permanent mark
on the emulsion.
• Interval Timer
An interval timer is a device that
measures the time between the beginning
of a process and its end. Any
timer (such as a clock, wristwatch or
stopwatch) with a second-hand will
do fine. There are of course a variety
of very nice timers specifically designed
for darkroom use ... but you
don't need one.
• Negative Clips
When you've finished processing
your film, you'll need to hang it up
to dry. Once again, there are special
metal clips made for this purpose . . .
and, once again, you don't need
them. Plain old wooden clothespins
work just as well. Whichever you use,
place one clip on each end of the film,
using one to hang the top up, and the
other to weight the bottom down so
the film doesn't curl.
Processing Tips
The golden rule of processing is BE
CONSISTENT. Once you have
established the chemicals, procedures
and times that work for you, stick
with them. Change nothing without
a good reason. You will then always
be able to identify and correct any
problems quickly. If, on the other
hand, you never do the same thing in
the same way twice, you're far more
likely to encounter some unpleasant
surprises . . . and far less likely to
know what caused them or how to
correct them.
The trickiest part of film processing
is getting the film loaded into the
developing tank. After that, all you
need to worry about is correctly timing
each step.
Before you risk ruining a roll of actual
photographs, practice loading
the tank with a blank roll until you're
sure you have it down pat. There's
nothing quite like the panic caused by
discovering that a roll of precious
film is not loading correctly. With
practice, you can avoid that ex-