Black and White Reversal Processing at Home

reversal processing film strips

One of our customers sent us this article about B&W reversal processing that we wanted to share with everyone…

Article and images by Brandon Eaglesham –

Shooting film is pretty cool already but without use of the darkroom at my school, and my bathroom setup out of commission temporarily, most of the fun of developing film into nice prints is lost if all you can do is scan them to a computer. Knowing colour reversal is possible through E6 chemistry, and colour film does have a B&W silver halide layer on it, it must be doable with standard black and white film too!

I found the process originally on Ilford’s website, but their method calls for some nasty chemistry that I didn’t want to have to purchase or store. Having made Parodinal developer from Tylenol at home, and being an avid caffenol user, I knew there must be way to do it with household chemicals.

I found a recipe by a Karl Matthias that uses household vinegar and peroxide, which can be found here: https://imager.ie/black-and-white-reversal-with-hydrogen-peroxide/, and gave it a shot using my Parodinal as my developer for this attempt.

Shoot your favourite clear-emulsion black and white film, I was told Rollei 400 has a clear base so that was my choice. Slower films like FP4 or tmax100 can work too. Ilford Delta or HP5+ will not work very well but may produce interesting results.

Starting out, it may be good to make a test strip of 5 shots, at -2,-1,0,+1,+2 so you can dial in with your exposure, I like to live dangerously, so I took the general rule and overexposed by one stop. In general, this this is the rule of thumb for reversal or cross processing. It is really important to nail the exposure as you can’t correct like you can during print making, these are the final images you will end up with. I recommend an automatic E-TTL camera, or superb light metering skills.

I used a Canon EOS 7E loaded with Rollei Retro400s for my first attempt.

First Development

Develop your film as normal in a standard Patterson tank with your favourite developer accounting for the one stop overexposure. If times for your film are not known at the new speed, a good rule of thumb is that for a one stop overexposure is to divide the box-speed development time by 1.5. So, for example, Rollei IR at 400 ISO, in Rodinal 1:50, is 22 minutes, a one stop pull is 22min divided by 1.5 or 15 minutes at 20C

Pour developer into a container to temporarily store it.

Wash for 5 minutes at 30C, drain

Prepare your bleaching solution

– 300ml Hydrogen Peroxide 3%
– 21ml white or distilled vinegar 5% acetic acid (malt vinegar works too, 5% is the standard for Heinz brand vinegar)

This is for one roll of 135 film, for 120 film, use 500ml and 35ml respectively.

Microwave at 10 second intervals until bleaching solution reaches 40C.
Also prepare white bowl filled with 30C water.
Add solution into development tank agitating as normal for 6 minutes, make sure that you are NOT using the sealed lid during inversion as the peracetic acid can produce vapour and blow the lid off.

Now you can take off the lid of your tank. The film should be milky, the specific colour will depend on your film. the Rollei Retro I used was like really spoiled milk coloured.

You should see somewhat positive images in your bleachy film, once they stop changing, which took the approximately 6 minutes mentioned, you can take it out and place it into the bowl of water, discard the bleaching solution into your waste container.

Second Exposure

Unspool your film and re-expose to the light. Holding your film approximately 1 foot away from a tungsten or halogen bulb for one minute on each side is sufficient. Indirect daylight may also be used but lots of UV rays can cause the film to print out. The bowl is to keep everything contained and wet/safe while unspooling and respooling.

Respool the film and wash for another 5 minutes at 30C, drain.

Second exposure reel reversal processing

Second Development

Develop your film a second time using the developer you stashed in the beginning. Use the same amount of time and temperature as the first time.

Final wash

Fix and wash as normal. (There is some discourse about the necessity of fixer in this process as all the silver is used during the bleaching and second development, but it can’t hurt to do anyway.)

Enjoy your positives. My positives have this nice warm cast to them that the scanner removed, so I attempted to add them in post, it kind of feels sepia now 😛

For more experimental shots, I sometimes post my pictures on my Instagram @sirwilliamofeos

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