The DARKROOM COOKBOOK, Third Edition

REPLENISHMENT OF DEVELOPERS
Film Development 49
Several of the fi lm developers included in The Darkroom Cookbook have companion replenishers
whose formulas are also given. However, I do not recommend the use of replenishment
unless you are operating a high-volume lab. There is no advantage or savings in replenishing
for most small-volume, home darkrooms, and there are numerous disadvantages. Among them
are the possibility of bromide buildup, resulting in bromide drag, developer oxidation, and
inconsistent results.
PUSH PROCESSING
One of my early infl uences in photography, Rodger Davidson, told me, “You can’t push fi lm!
All you are doing is underexposing and attempting to compensate in the development! Don’t
you know, if it’s not on the fi lm you can’t develop it?”
Technically, Rodger was right—you can’t push fi lm. But in situations where it is necessary
to squeeze the last nth of shutter speed and maintain as much depth of fi eld as possible, get
an image on the fi lm and do whatever has to be done in the darkroom to make a good print.
Pushing fi lm means to ignore the manufacturer’s ISO rating and creating your own
Exposure Index (EI) by setting your ISO dial at a higher number. 6 For example, instead of
using Ilford HP5� at its factory rating of ISO 400, you would set the ISO dial to EI 1600, EI
3200, or even EI 6400. To be successful requires a developer that will reduce the maximum
amount of silver possible. Crawley’s FX 11 and Diafi ne-type developers are designed for that
purpose. However, using high-energy developers such as these usually results in increased
fog levels and graininess. Instead, I recommend using D-76H, Kodak T-Max developer, Kodak
XTOL, or Ilford DD-X. Paul Lewis’ Mytol formula, a substitute for XTOL which you can mix
yourself, can be found under Formulas.
Almost any panchromatic fi lm made today can be pushed one stop with little or no discernible
loss in quality. For example, Kodak Tri-X can easily be pushed to EI 800 and Ilford
Delta 3200 (which is closer to EI 1200 than it is to ISO 3200) can easily be pushed one stop
to EI 2400. Try adding 25% to the normal development time for Tri-X, and 25% to 40% with
other fi lms for a one stop push. With testing and experience, you should be able to capture
almost any event on fi lm, regardless of how little ambient light is present. (See Yuette at the
Coffee House on page 53.)
Increasing Film Speed
Increasing fi lm speed is not the same as pushing. Pushing, as noted above, is to underexpose
and overdevelop the fi lm by simply turning the ISO dial to a higher EI and overdeveloping.
Beyond one stop the primary result is a negative with loss of shadow detail and over developed
highlights. Increasing fi lm speed is a process by which the fi lm's ability to respond to
low levels of light and record detail in shadow areas is increased.
6 ISO is the speed rating of the fi lm as per factory specifi cations, determined through controlled testing;
EI is any speed other than the factory spec ISO that you choose to use.