Black & White reversal: Reduce contrast?

pkr1979 · Jan 20, 2024

Hi all,

When doing black and white reversal, is there a way to reduce contrast? Possibly without changing the ISO?

Cheers
Peter

Sirius Glass · Jan 20, 2024

Slide film [color] has lower contrast than color negative film. Black & white film which is negative film processed as slide film could be expected to have more contrast than a color slide. There are several paths to lower contrast:

Bleaching
Farmer's Reducer
Masking using film, rephotographing and developing
Masking using Photoshop or GIMP, rephotographing and developing

revdoc · Jan 20, 2024

Pre-flashing will do it. I use this to control contrast when reversal processing lith film. It increases the effective film speed to some extent.

This shouldn't be confused with pre-flashing negative film. The required controls are somewhat different.

If you want to try this, pre-flash can be done in camera, just prior to the main exposure. That will make the preflash easy to control, but it isn't very convenient, because you have to do it for each frame.

You can also post flash before first development. The results are the same.

You will have to re-calibrate your first development, which be shorter.

pkr1979 · Jan 20, 2024

Thanks @Sirius Glass
Id be interested to know how I could change my bleaching? I use dichromate bleach for about 3 min 30 sec.
Also, how is Farmers Reducer used? My process is as follows: first dev, bleach, clear, Iront Out, fix.

@revdoc Preflashing doesnt sound so convinient for 35mm film

Sirius Glass · Jan 20, 2024

pkr1979 said:
Thanks @Sirius Glass
Id be interested to know how I could change my bleaching? I use dichromate bleach for about 3 min 30 sec.
Also, how is Farmers Reducer used? My process is as follows: first dev, bleach, clear, Iront Out, fix.

@revdoc Preflashing doesnt sound so convinient for 35mm film

I have not enough experience to clearly sort out the various bleaching methods. I have only done it by eye. Others who have more extensive experience will need to step in.

Bronson Dugnutt · Jan 20, 2024

Pre-flashing, lowering the film's speed rating, or adding a fixative (thiosulfate or thiocyanate) to the first developer essentially perform the same function - remove some proportion of the silver or silver halide that serves to form the initial negative image. This may or may not give you the 'reduced contrast' you seek but that's a question for the sensitometry folks.

My first suggestion would be to simply use a less contrasty first developer. What film and first dev are you currently using? Something like Fomapan reversal doesn't require a first developer as strong as stock D-19 like Tri-X does, for instance.

pkr1979 · Jan 21, 2024

This is Fomapan R and Adox MCC developer.

Bronson Dugnutt · Jan 21, 2024

I'm not familiar with Adox MCC, but being a paper developer I assume it performs similarly to something like Dektol.

I posted some R100 reversal scans where I used D-19, which is similar in activity to diluted Dektol. Whatever you're doing now, try a higher dilution and/or shorter first developer time.

6 minutes in D-19 was right on for my R100 exposures.

Ivo Stunga · Jan 21, 2024

Pull processing helps.

Reduced agitation frequency helps.

Stand reversal helps massively.

Reduced developer concentration should help, haven't tried.

Leave Bleach alone if it does the job, all the magic happens at the 1st stage. Sirius was talking too much.

Ivo Stunga · Jan 21, 2024

My R 100 at box speed with Ilford Reversal looks like this. Didn't do anything special at all to "tame" the contrast - R100 is not contrasty film in my book:

pkr1979 · Jan 21, 2024

Thanks fellas. Im just gonna reduce first developer time while shooting at the same speed and see where that takes me.

pkr1979 · Jan 21, 2024

@Ivo Stunga - did you do stand development for reversal? How was your process?

Ivo Stunga · Jan 21, 2024

I've tried Delta 100, an unknown Soviet film, and Aviphot 80. Stand and Semi-stand gives Bromide drag with PQ Universal, but minimal agitation (every 15min) gives you pretty normal contrast.

First stage of it was 6/600ml, 90 minutes with 1 inversion every 15 minutes - rest of reversal as usual. Tank full, roll suspended in the middle of Patterson shaft so film is not sitting in own development byproducts for a long time, - it's said this works against Bromide drag and I got none by trying that.

pkr1979 · Jan 21, 2024

Thanks. Might try this at some point

Ivo Stunga · Jan 21, 2024

Do post how it went if you do so.

pkr1979 · Jan 21, 2024

Will do.

Philippe-Georges · Jan 21, 2024

pkr1979 said:
Hi all,

When doing black and white reversal, is there a way to reduce contrast? Possibly without changing the ISO?

Cheers
Peter

what film?

Some years ago, I used rather a lot of B&W reversal, processed in my COLENTA machine, meant for scanning to be offset book printed. See as an example: https://www.photoeil.be/books/dieter-roth.html
After some testing I chose the DELTA100 film (4"x5") and found it rendering a pleasant normal-to-soft contrast, whilst films like the FP4+, HP5+ and Tri-X to be too soft.
I did not feel the urge to reduce the contrast any further, tonality was very 'wide', having a nice DMAX and the image presentation very attractive.

I used a (slightly-) modified home brewed AGFA DIA DIRECT processing, which needed an intermediate exposure.
Now ADOX offers a similar processing kit, and two films too, based on the famous AGFA SCALA: https://www.adox.de/Photo/adox-scala-reversal-kit/
AGFA SCALA was somewhat the successor of the AGFA DIA DIRECT.

PS: I am not affiliated to ADOX, just a fan of Europe made photo products...

dokko · Jan 21, 2024

Bronson Dugnutt said:
My first suggestion would be to simply use a less contrasty first developer.

totally agree with that, that's the easiest and most effective way to affect the contrast in a larger degree.

for more subtle changes, reducing the concentration and/or agitation of the first developer will also work.

pkr1979 said:
Thanks fellas. Im just gonna reduce first developer time while shooting at the same speed and see where that takes me.

pretty likely you'll just get darker images...

pkr1979 · Jan 22, 2024

Hi all - figured Id just give an explanation on why I ended up trying FomaPan R with MCC. The best results Ive got so far is with Adox Scala 50 developed in PQ Universal (this developer has actually always given me the best results when doing reversal, I dont know why) and Iron Out for second exposure and second developer (very convenient). I have nothing to complain about when it comes to using this combination. However, as I have MCC developer for silver chloride paper and because of its shelf life it would be convenient to make that work with Scala 50 (PQ does not have the same shelf life and I dont know how it works with silver chloride paper). And it does, but it is not as good as with PQ (Ive only tried it once though). I had two rolls of FomaPan R (still one left) and I just figured Id try it with this combo. If id doesnt play along I'll just continue with Scala 50, and if this doesnt give me what I want in MCC, I'll use it with PQ (having to find a way to extend its shelf life).

Ivo Stunga · Jan 22, 2024

I buy 5 liters of it per I dunno, 3 years? Then put in 4x 1l glass bottles, top off with butane, and 2x 0.5l bottles for immediate use, topping up with butane after each use.

Have nothing to complain about - even last batch with crystals fallen out of solution when I received it - doesn't even change color.

pkr1979 · Jan 22, 2024

Im probably getting som 100ml bottles if I end up down that road

Ivo Stunga · Jan 23, 2024

Could be too much of a hassle and empty air to fight with. People also use wine bags for their chemistry... If that keeps air out too, should do fine.

pkr1979 · Jan 23, 2024

Im not doing it from 5 liter containers ;-)

Black & White reversal: Reduce contrast?

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