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How to develop film

Processing black and white film is something anyone can master at home. There's nothing especially difficult about it: patience and attention to detail will get you there. There are five stages to the process and the first four have to take place in the dark. That doesn't mean that you'll be left groping around but rather that the film should be kept in the dark. For roll film such as 35mm and the 120 medium format size, a developing tank is used. It consists of a light-tight drum or container, usually stainless steel or plastic, and a "spiral" normally made of the same material. Here's the way it works:

1. In complete darkness or by using a lightproof changing bag, load the film onto the spiral and pop it in the tank. The darkness has to be complete. Incomplete darkness is just the same as "a little light" and light will fog the unprocessed film and quite probably ruin it. Mastering the knack of loading the film usually takes a few dummy runs in daylight with a used film. If you don't have a used film lying around, then buy the cheapest supermarket colour print film you can and sacrifice it for the cause. First of all, trim off the tongue of the film with a pair of scissors, push the film into the start marks on the spiral and then twist the spiral two and fro to "walk" the film onto it. Then put it in the tank and close the lid.

2. The next stage involves development. Start with the right amount of developer according to the instructions and aim, through carefully adding warm water or cold as needed to get it to the desired temperature. That's usually 68F or 20C but check the instructions. If you've mixed it up to the right volume and it's still too hot or to cold then sit the container in a bath of hot or cold water checking it regularly and making sure that it doesn't up-end itself in the water bath. Get your clock or watch ready and pour the developer into the tank starting the timing when you're sure the developer has covered all the film.

Tap the bottom of the tank a few times on a solid surface (gently) to dislodge any air bubbles sticking to the film and invert the tank continuously for ten seconds - usually about four or five inversions. Invert the tank once or twice every minute. About ten seconds before the allotted time for development is up, either pour the developer down the drain if its a one-shot type or into a storage bottle if you want to re-use it. Try to keep the room temperature at about the same level as the developer or sit the tank in a bath of water at the same temperature throughout development to avoid a drop-off that could lead to the film emerging underdeveloped.

3. Of course, before starting the development part (or during), you should have prepared the chemical that goes in immediately afterwards. It's called a stop bath and brings all development to a complete end. It has to be within a degree or two of the developer to prevent sudden temperature changes from stressing the film's delicate light-sensitive emulsion. As soon as developer has drained from the tank, pour in the stop bath and invert a few times. You can relax a little at this point as development has now ended and the film will sit quite happily for a little while in the stop bath.

4. Next comes the fixer which, in the manner of the stop bath, should have been prepared in advance and kept at the same 20C in readiness. Once the stop bath has been drained, pour in the fixer and invert for 30 seconds then twice on the min. After the correct time is up (normally around a couple of minutes - it'll say on the fixer container) pour the liquid back into a storage bottle for future use.

5. The final stage is washing the film. You'll notice a pattern beginning to emerge here - it's a good idea to have some water at 20C to hand just to rinse the fixer off the film a couple of times before proper washing. Staying in the fix too long can bleach delicate highlight detail. For most of us it's more a theoretical risk but life's risky enough without wantonly threatening our highlights for no good reason.

There are several good ways of effectively washing a film. The more profligate among us will remove the lid from the developing tank and run a hose from the tap (water about the same temperature as the rest of the chemicals) straight down the centre of the spiral and leave it there for ten minutes. That does the job but uses a lot of water. I think the best and quickest way is to give the film a couple of quick rinses using a change of water. Then change the water and give it ten inversions, change again and twenty inversions and finally change again and forty inversions. Just to be on the safe side and because I can get a bit anal about these things, I like to repeat the 40 inversions with another change of water. When the washing has ended, use a little wetting agent (a liquid applied in tiny quantities that reduces the surface tension of the water and causes it to run off the film without leaving marks) to aid drying.

Run a shower
Once washed, the film is hung up to dry in a dust free place where the air wont be disturbed. I find the shower cubicle is an ideal spot - but not if anyone uses talcum powder. First of all, run the shower for a few minutes to generate some steam and then wait for the water droplets to fall to earth taking airborne dust with them. I suspend a wooden clothes peg from the shower rail by means of some plastic-coated wire, attach the film and hang another one on the bottom to weight the film so it dries nice and straight.

If your water quality if suspect and you find there are some scum marks on the film once it's dried, it might be a good idea to use filtered, distilled or deionised water when mixing the chemicals and as a final rinse with the wetting agent added. Another problem you might experience are drying marks on the film where water has beaded and dried slowly leaving a tell tale ring behind. The solution here is to wipe the water off the film when hanging it up. There are special tongs available with soft rubber blades attached for the very purpose. They are run down the film like a pair of fingers and wipe the water away. However, they must be kept scrupulously clean to avoid a stray particle of dust adding a long scratch to the film.

That's basically it, then. Nothing too complicated there.

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