Thursday, May 31, 2007

Developing BW Film

Somebody wanted to know what was involved with this and if you need a darkroom (no) and I thought I might as well make it a blog post.

There's a zillion guides out there in great detail - this is just to give the general idea for folks who are curious. There's also more than one way to do this, but this is what works for my situation.

Basic Prep

First I grab a developing tray and fill it with water. I try to get it around 68 degrees. I have a thermometer with a bold line at 68 degrees to see how far off you are. At this point it just needs to be in the ballpark (66-70, say). I get some pure water (RO/DI since I have it around, but distilled is fine) and mix up the developer from concentrate. The fixer I would typically already have mixed, but if not I mix that too and there's a rinse chemical as well.

I put containers with the mixed developer, fixer, and some more pure water in the water filled tray. At this point I add some hot or cold water as necessary to push it closer to 68 degrees. It's going to shift around a bit more as the chemicals come up to temperature, so again, no need to be super precise but it should be pretty close by now.

I hang a bit of string in the tub to dry the film on and put some clips on it.

Getting the film into a tank

The next bit is to get the film into a special developing tank which lets chemicals in and out but keeps out light. I use one made by Jobo. Mine will handle either two rolls of 35mm or 120 (medium format) at once. You put the reel and various tank bits into a changing bag - think of two black pillowcases, black, one inside the other. There are zippers to put stuff in, and tight little holes to put your hands through. It's a bit like the "boy in the bubble" but keeping out light, not germs.

You have to take the actual film away from any canister, paper backing, tape, etc. This can vary a bit by brand. Then you have to roll it onto the reel. There's a bunch of little tricks - it's kind of hard since you have no idea what you're doing except by feel. You need to sacrifice a roll the first time you do it and keep practicing in the light until you have it down, and then keep doing it in the bag until you're confident. Obviously if you can't get it on the reel there's not a lot you can do - unzip the bag and it's exposed.


So by now the temperature should be pretty stable. If it's not right on 68 degrees I'll fine tune it and go away and come back in a bit. But usually it's actually spot on now that I have a bit of experience. I'll double check the actual developer temperature since that's the most critical temperature. People argue about how close it really has to be but probably within a degree is fine. The good news is that once it's right it will stay pretty stable since room temperature isn't vastly different and there's a fair amount of water in the bath.

Then there's a rather tedious stage of adding chemicals in the right order, timing them, inverting the tank periodically to keep fresh chemical near the film, various rinse stages. The exact time varies depending on your film and developer, but it's something like 30 - 45 minutes for the whole process. For some of the rinsing you can wander around a bit - I actually wrote most of this while it was rinsing.

The Rest

I run my fingers down the film to get most of the water off, then hang it up. Takes about an hour and a half to dry. Then I get some scissors and cut off three shots at a time and scan them, and then put them in a plastic holder that goes into a three ring binder.

It takes me somewhat over an hour to do the two rolls (not counting the scanning) - just about as long as it takes to drive to the lab and back. Since I'd have to drive there again to pick them up, I might as well save gas and money and just do it myself. Other folks do it because they want some exotic developer or they just don't trust their local lab or may not even have one around that does black and white. The inital setup cost to buy everything is around $100 so it might take 15-20 rolls to break even in terms of cost, but then after that point I save about $6 per roll plus gas money.

Now, for color conceptually it's the same. The problems are all in the details - you have to be very precise about temperature and development times or you'll get junk. It's possible to do it at home but hardly anybody bothers.


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