It’s true: processing film ranks right up there with running, and with making good-looking entrees.
Let’s consider what one would need to make ’em (negatives) at home and how to do it. You can find this information at plenty of locations on the World Wide Intercom, so I’ll do it as though we’re chatting.
Bare minimum: reel & tank & lid & cap, clock, thermometer, dark. Developer, fixer, water.
One step up: a photo thermometer, a (darkroom) timer, hypo clearing agent, wetting solution.
The chemicals, in reverse order:
Wetting solution is sold as LFN or Photo Flo 200 (you don’t need Photo Flo 600). For either, drop a drop or two into a pint of water for a final rinse of 30-60 seconds. Any suds you generate in this will run off and leave nothing on the film. The pint is usually good for all day. An alternate method I’ve not tried is to spray the film, hanging in position to dry, with distilled water from a plant, Mister (I mean, a plant mister).
Hypo clearing agent (HCA) breaks down the fixer that remains on film (or in paper fibers) so that the wash times may be kept to an efficient minimum. Implied in that: enough washing makes HCA unnecessary. Kodak makes it, and so does Edwal and others; it’s easy to make with just a couple of common chemicals and a scale. You know what, though: just pick up a quart of Perma Wash. 3 ounces makes a gallon; nothing to it.
Fixer is a sine qua non of processing, so get over the aroma, OK? Most gang darkrooms use Kodak Rapid Fixer (there are equivalents) because it’s cost effective, but the critical thing is not to overextend its use. It’s very important to know how much material has gone through a given batch of working solution fixer. I’ve always been reluctant to mix from packages in powder form (fear of contamination), and the extra expense of liquid concentrate is a small upgrade. Until I changed fixers a while back (BIG upgrade; more later) I usually preferred Edwal Quick Fix.
“Working solution?” Most, if not all, rapid fixer liquid concentrates get diluted 1:3 for film and 1:7 for prints, although there are reasons to stick with 1:3 for paper as well. This means that for our paltry needs, eight ounces of rapid fixer makes a quart of working solution fixer good for a dozen rolls of film in a six-month period. Be sure to stir thoroughly, until all the striations are gone, and it will remain in solution from then on.
So. If you make HCA by mixing one ounce of Perma Wash into a third of a gallon of water, that will last as long as the quart of fixer. Keep a tally and dates on the containers. Simple and reliable.
The biggest, most important deal of all is the developer. Perhaps no one but you will be aware of the difference that the choice of a developer makes, but oh, you’ll know. Seems odd, I know, not to touch on the fine points of types of grain and compensating qualities and exposure indices, but right now let’s be practical.
Xtol is currently the reigning developer in terms of quality, flexibility and cost effectiveness; it’s easy to mix at room temperature, it’s relatively environmentally friendly citric acid-based) and it acts as its own replenisher. The only catch is that it must be purchased and mixed in FIVE LITER batches! Originally it was also available in one-liter packages, but there were quality control problems in manufacture. This brings us back to previous gold standards among developers: D-76 and HC-110.
D-76 was first concocted (see how far out of my way I go to avoid saying it was developed?) in 1927 as a “fine-grain” motion-picture film developer. It’s still the standard to which every other formula compared. There are home-brew variations, but every darkroom worker has it memorized: 400TX, 1:1, 68F., 10 minutes. The stuff is available in packages to make one quart at a time. For 35mm that’ll do eight rolls at a 1:1 dilution. It keeps for six months in a filled and stoppered glass bottle, and when the bottle becomes partially full, the guarantee slips to 2 months; still not bad.
HC-110 comes as viscous pint (yellow or orange? It changed from one to the other) that you first dilute to a half-gallon, and then further as needed. There are at least 8 recommended dilutions, all with their own times. In school we diluted only a half-ounce or so at a time from the pint; I don’t know why we thought that was accurate, with its syrupy consistency. Times are seductively short. Don’t fall for it. Only if your processing techniques are flawless would I suggest you go this route.
What else do you need? A dust-free place to hang film to dry, and a clip for hanging. I don’t know any dust-free places, but if things aren’t stirred up you should be fine. Keep large dogs out of the room, and don’t use catnip as a weight on the bottom end. Although a slight weight is nice to have (especially in low humidity) to discourage curling, it’s equally effective to crease the blank leader backward against the curl twice, and all will be well.
If anything is unclear or you want me to elaborate, just post a comment. As Ted did. Thanks for the kick in the pants.
Update: http://www.holgablog.com/2009/03/20/processing-bw-film-and-how-i-do-it/ is a pleasant tutorial by “Veronica.” It includes a link to an Ilford pdf of the same stuff in more formal terms.
2009/07/15
Categories: Information, Tools & Materials . . Author: mrdplus . Comments: Leave a comment