C41 (color negative) processing is tricky and sensitive, so it's difficult to do at home. I'd still like to learn about film processing, and have heard that black and white negatives are fairly straightforward.

How do I develop black and white negatives at home? What chemicals and equipment will I need?


2 Answers 2


Developing film is a rewarding, easy, and forgiving process: I used to do it with young children at summer camp and it never failed (even in 85 degree weather!).

At a minimum you need a developing tank, developer, and fixer.

It helps also to use a stop bath (a mild acid, essentially dilute vinegar but purified).

You also temporarily need a perfectly dark room, like a closet at night. (I once used a basement at night with aluminum foil taped over the windows. Check the room out by sitting in it for 5-15 minutes with your eyes open: if you still can't see even a glimmer, you're fine.) If you plan to do this often, get a changing bag: the film and developing tank go into it along with your hands. Inside this lightproof bag you open the film canister (using a bottle opener), load the film in the developing tank's reel, place the reel in the tank, close the tank, and you're good to go: everything else happens in the light.

For mixing the chemicals you will want a reasonably accurate way to measure liquids. And light-proof plastic or glass bottles to store them.

Finally--this is essential--you need a thermometer that is accurate in the range 65-75 degrees F (18 - 24 degrees C).

The basic process consists of loading the film into the tank (practice in the light with a roll of old exposed film), pouring developer into the tank, agitating the tank on a specified schedule ("agitation" means inverting slowly once every 30 or 60 seconds), emptying the developer, pouring in the stop bath (or water), emptying that, pouring in the fixer, emptying that after a period of time, opening the tank and rinsing the now-developed film with water (under a tap usually does fine), and hanging the film in a dust-free place to dry (I used to clip the film to the shower rod in the bathroom and weight the lower end with a couple of clothespins). Afterwards you cut up the negatives and place them in glassine or plastic sleeves for protection. Then you're all ready to make a contact sheet and proceed to enlarge them...but that's a topic for another day.

Instructions for development time and agitation usually come with the developer, which often is a packet of powder you mix with warm water and let cool. The time usually is from 2 to 8 minutes, depending on temperature (whence the need for the thermometer); the whole process takes about 30 minutes plus drying time.

Make sure you rinse everything thoroughly and clean up carefully when you're done: these chemicals don't do good things to the bathroom or kitchen furniture if left lying around. And if you store the chemicals in a public place--even temporarily--please label the bottles clearly and carefully. When I was a kid and first learning how to do this I put the warm, newly mixed fixer into the refrigerator to cool. It was in a recycled tonic water bottle, not too well labeled with a magic marker. My mother made a gin-and-fixer cocktail with it and almost drank it...

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    \$\begingroup\$ Just a couple of notes: a liquid developer (such as HC-110) is often easier to work with -- powders have a nasty habit of precipitating things out of anything but perfectly pure water some time after they look mixed. Oh, and a rinsing/sheeting agent will help a lot during the drying process (spots are hell). And remember to record the development time, temp, etc. -- once you find a recipe that works for you, you'll want to be able to repeat it. \$\endgroup\$
    – user2719
    Jun 8, 2011 at 12:06
  • \$\begingroup\$ Good points, @Stan. I never had precipitation problems, probably because I mixed powders carefully and thoroughly in warm (tap) water and then let them cool. (If I were doing this today I would use filtered water.) \$\endgroup\$
    – whuber
    Jun 8, 2011 at 12:45
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    \$\begingroup\$ +1 for a great write-up. For an incredibly cool alternative to the usual chemicals, check out what instant coffee, washing soda and vitamin-C can do (caffenol.blogspot.com, via blog.makezine.com/archive/2011/06/…) \$\endgroup\$
    – user2559
    Jun 8, 2011 at 16:35
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    \$\begingroup\$ This was a great write-up. In addition, there are tons of YouTube video on all aspects of development. Sometimes video is worth 1,000 words. \$\endgroup\$
    – MikeThomas
    Jun 30, 2011 at 20:00
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    \$\begingroup\$ Note that if you only intended to get them scanned do so before you cut the roll into strips. Just roll the film up and place it in a zip lock bag. It's easier and sometimes even cheaper to get it scanned as a single roll and not strips. \$\endgroup\$
    – Chandler
    Jul 1, 2011 at 19:25

Though, I have never tried it (yet), I saw this movie on YouTube, http://www.youtube.com/watch?v=rROBVLNEb3M that I think explains the process nicely.

  • \$\begingroup\$ (+1) That's a good introduction. Within a short time it shows a lot of little details, such as how to agitate a tank and keep the bubbles out, that I learned only through extensive reading and experimentation long ago. \$\endgroup\$
    – whuber
    Jul 2, 2011 at 21:07

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