Chihiro (red filter). Tri-X at 1250 in Diafine.



Recently I mixed up a fresh gallon each of Diafine solutions A and B. What better time to write about this wonderful tool? 

Summertime. Adox CMS20 at 25 in Diafine.

UPDATE: I’ve linked each photo to a larger version so you can get a better sense of the grain. All negatives were developed by hand in a small tank and scanned with a high-resolution film scanner. I have wet-printed a few of these and they look remarkably similar (but naturally even better)!

I use Diafine a lot. It’s a very good developer, easy to use, and it gives consistent results. I mention it a lot in this blog, but I haven’t really given it a proper write-up. Perhaps that’s because it’s been my day-to-day standby for as long as I can remember, and I think it’s more interesting to write about the times I’m using/learning about other developers.

One salient feature of Diafine is its longevity. I have never had a batch of it go bad other than from contaminating it (accidentally pouring something that wasn’t solution A into the solution A bottle). What does happen is that solution A will lose volume slowly. Because A literally soaks into the film, a tiny bit is lost with each cycle. I keep a second bottle of A on hand (I label it A2) and pour a tiny bit into the A bottle every couple of cycles. In an emergency, I’ve used A2 as my primary batch, and then mixed up a new A2 replenisher. You will also see both baths change color over time. In fact, B will get downright mucky. Not to fear. It still works. If it bothers you, you can filter it.

Hats! Kodak Plus-X at 400 in Diafine.

Let me clear up a common misconception about Diafine: you cannot shoot at many film speed settings on the same roll and then develop in Diafine and expect wonderful results. It is not a potion that magically sorts out your exposure choices. What Diafine does is develop any given film exactly the same way, every time. You cannot push or pull with Diafine—you can develop to a different exposure index though (more on that next). You can’t develop for longer or shorter or hotter or colder and expect reproducible changes.

How Fiction Works. Kodak Tri-X at 1000 in Diafine.

On the side of the Diafine box is a table that shows the recommended exposure index for various films. If you look up 35mm Tri-X, it is suggested to shoot it at 1600. Plus-X is 400. TMAX400 is 640. The idea is that as long as you expose the film as if that were the speed of the film, Diafine will develop it properly. Mind you, the listed film speeds are starting points. Most people I’ve talked with agree that 1600 for Tri-X is underexposed, for example (I use 1000-1250).


The Dime. Adox CMS20 in Diafine.

When you mix up your first batch of Diafine, you may find that the A powder has a difficult time dissolving. In the several batches I’ve mixed, I’ve never had it dissolve completely. While you may be dismayed at the white bits floating in the batch you’ve just been stirring for 20 minutes, don’t worry. It will still work if you’ve made a reasonable effort to mix it thoroughly.

Using Diafine is very straightforward. Pour solution A into your tank, tap for air bubbles, agitate three gentle inversions every minute for three minutes. Pour solution A back into its bottle. Pour in solution B, agitate exactly as with A. Pour solution B back into its bottle. Don’t use stop bath–rinse with water for a minute. Fix and wash normally. 

Gowanus bike. Ilford Delta 100 at 80 in Diafine.

Diafine’s usable temperature range is 70-85F, so you usually don’t have to mess with water baths to regulate temperature or cool down/heat up your bottles. And if you leave your film in for longer than the stated three minutes, you’ll be fine. Diafine is indeed a lazy person’s developer. Because it’s so easy to use, I’ve been guilty of screwing it up more than I have any other darkroom process. I’ve poured B back into A (a big no-no) a couple of times over the last decade, because the loose requirements of the developer give my mind license to drift. Don’t do it. Act as if it’s a mission-critical process and give your film and its photographer the respect they deserve!

I try to stay within the recommended temperature range, but in the dead of winter when nothing in our home seems to warm up beyond 68F, I generally do 4 minutes in each bath (or use another developer).

Canon VT Deluxe. Kodak Tri-X at 1000 in Diafine.

On the phone. Tri-X at 1250 in Diafine.

Diafine is also lauded for not blowing out highlights. This, and its effective “push” of Tri-X, makes it a great developer for on-the-fly or street shooters.

Chihiro. Kodak Plus-X at 320 in Diafine.

Once you get the hang of it, you might want to use it for everything. As long as you’re sticking to the film speed guidelines, you can mix and match films in your developing tank and trust that everything will turn out.

Splat. Ilford Delta 100 at 75 in Diafine.

Here are some tips to using Diafine, compiled from over 10 years of regular use:


Label your bottles and caps. I hope none of you reading this are as clutzy as I am, but marking your caps “A” and “B” with a Sharpie takes a couple of seconds and might save a batch.


Measure the temperature of your Diafine, then adjust your rinse water and fixer (if you’re feeling ambitious) accordingly.

Start with the box guidelines and then judge the results for yourself. Especially for beginners, instructions can be a crutch, even when useful. If you think all your photos turned out too dark or too light, act on that and don’t assume that you must have done something wrong. Try a different film speed next time. I have a lot of photos that turned out fine shooting Tri-X at 1600 for Diafine, but eventually I found that 1000-1250 gave me better results overall.

Night moves. Kodak Tri-X at 1250 in Diafine.

Don’t assume that just because you found a film listed on the side of the Diafine box or online that it’s going to work out well. Diafine’s a useful tool, but it isn’t a good match with some films to my eyes. Anyone can argue for or against any film and developer combination, so I’m not going to give my blacklist here. Trust yourself. If you don’t like the results, move on. Likewise, go ahead and try Diafine with a film that’s not listed. Be adventurous.

Rocery. Kodak 320TXP 4×5 at 1000 in Diafine.

Adox CMS20 (at 20?) in Diafine

Do experiment. I was told, unequivocally, that Adox CMS20 had to be developed with its associated Adotech developer. I tried Diafine instead with astonishingly good results. Now I have an expired bottle of once-used, expensive Adotech because I won’t use anything but Diafine with CMS20.

Kodak 320TXP (120) at 1000 in Diafine.

Do buy it. I fear the day when I won’t be able to reorder Diafine. While I’ve wanted to develop in larger quantities (I often use a five-roll Paterson tank), another reason I mixed up gallon batches of the stuff is because the quart size is increasingly difficult to find. I suspect the quart size has been discontinued (though I still see it on the distributor’s web site).

There’s plenty to read online about Diafine. I’m one of many moderators on a very friendly Flickr group dedicated to it here: You’ll see that people don’t just use it 3 + 3 (minutes) but also do things like develop twice or extend times in A or B, etc.

Consistent results, ease of use, longevity, wide temperature latitude—all great reasons to try Diafine. In my mind, any one of them is a good enough reason to try it, if you like the results you get. I’m especially fond of using it with Tri-X; I would say that the majority of frames I’ve taken in the last 10 years were shot on Tri-X, then developed in Diafine.

Now that I’ve bothered to write all this up, I’m looking forward to trying some films I haven’t tried in a long time (or ever) in Diafine. I’ll do my best to share the best and worst with you, in my opinion of course.

Feel free to ask questions in the comments, and please share your own experiences with this unusual developer!