BW reversal fail x2

[pkr1979]

Hi all! After 2 failed attempt on BW reversal I am need for some help :-) I've followed the recipe below except that I've been rinsing for longer than Im supposed to... considering this doesnt matter for E6 I've been assuming it doesnt matter for BW reversal either?

I have not developed a lot of black and white at all, but I have developed a lot of E6 with good results. In my first attempt I used to little potassium permanganate, resulting in a non reversed film. But the negatives themselves didnt look that bad, apart from some stripes... which I have never experienced developing E6. On my second attempt I used a lot more potassium permanganate, but the film wasnt reversed now either. Instead I got some very, very, very thin negatives... uneven and with stripes... what may be the cause of this? Ive mixed the chemicals and developed like this:

First developer: 100 ml Ilford PQ + 400 ml water.
Bleach: 485 ml water + 15 ml Sulfuric Acid 50 % + 1 g (from 0,2) potassium permanganate.
Clearing bath: 500 ml water + 5 g (from 2) sodium metabisulphite.
Second developer: 50 ml Ilford PQ + 450 ml water + 0,2 g stannous chloride.
Fix: 100 ml Ilford Rapid Fixer + 400 ml water.
Stab: 2,5 ml Ilfotol + 497,5 ml water.

Develop 2 HP5+ 24°C Jobo CPA2 75 rpm:
- First developer 10 min
- Water x2 30 sek (probably more)
- Bleach 8 min (not 3,5 min)
- Water x2 30 sek (probably more)
- Clearing bath 2 min
- Second dev 8 min
- Water 30 sek (probably more)
- Fix 4 min
- Water x7 2 min (probably more)
- Stab 1 min

Any tips to help me in the right direction?

[koraks]

I'd try the fogging step with light and leave out the SnCl from the second developer and see if that improves matters. Also, the fact that you got thin negatives suggests that your bleach isn't working to completion yet. I haven't tried a permanganate bleach; I only have experience with a dichromate bleach, which is lightning fast. I imagine that permanganate is slower.

[interneg]

As Koraks says, I'd try using light fogging to see if your fogging redeveloper is the problem. I think it may be - you probably need to separate fogging & redevelopment unless you are using sulfide for sepia toned transparencies. As I understand it, the mechanisms of BW reversal are somewhat different from E6, so don't always assume direct substitutions. You should also be using a powerful silver solvent in the first developer to ensure all the silver is developed - E6 does & BW really needs it too. Thiocyanate, thiosulfate, DTOD are the main choices depending on your bleach - do not use thiocyanate with a permanganate bleach however.

[koraks]

A friend of mine omits a solvent from the first developer and instead tweaks exposure and first development, and also adds adds fixing step at the end (also present in the above worflow). I've seen his transparencies on Adox Silvermax and they really are excellent.

[Pere Casals]

Any tips to help me in the right direction?

Hello pkr1979,

You don't mention what film you use. You should say all information to get a good diagnostic. While BW reversal is straight there are some films that have particularities... remarkably Adox CMS 20 and HP5+.

Let's go:

0) Congratulations for engaging BW slides, with some "technical" adjustments you will enjoy an amazing medium, beware, it creates addiction.

1) First and most important, reverse process can be done with lights open since the water stop bath after first developer, so do that at least for diagnostic, you will see what step fails. And you don't need the chemical fogging for the moment (as other said).

2) Don't test with full rolls, use 35mm frames. Shot an entire 35mm roll with the same scene, from another developed roll measure the blank not useful length at the beginning, from there cut say 30mm strips to make tests. If in the strip you have fractions of two frames this is irrelevant, you only want exposed strips to test.

3) Lights closed throw the strip in a tank with some 100ml of developer and develop as you want, you can use PQ or any other developer, like Xtol or D-76, at the end development will depend on how you expose. PQ is recommended sometimes because it is an energic developer that would allow low minimum density in the highlights. Then rinse with water (you may use an acid stop bath, but rinse well after).

6) From now you open the tank and you take the developed strip out of it, lights open, you won't close lights any more, you don't need darkness from now, and from now you will see what happens with your process.

7) in the developed (and stopped) strip you should see the yellowish emulsion with the black/grey stains that are developed silver. Next process (bleach) has to remove the black stains of silver and to leave the yellow emulsion. Right now you can evaluate if the exposure+development is good, you may visualize the result by thinking that the yellow areas will be dark in the processed slide and that the black areas will be clear.

8) Next: the bleach process has to remove the (metallic) black silver while not removing the yellow emulsion (silver hallide), you may see what bleaching time you require until the black is removed, a longer time may remove also the yellow emulsion you want it remaining. So you observe how bleaching goes with your eyes, if that does not works then report it.

9) With the clearing bath you will observe no change in the slide.

10) If the bleaching was OK, then you make the second development, now you have only yellow and clear areas, also lights open you throw the strip in a tray (white or grey, to see better) with developer and you will observe how the yellow is becoming black, normally second development is done to completion, so time just has to be long enough to develop all silver halide from yellow to black.

Second development can also be a control factor, not allowing to develop all silver halide for a lower resulting density, but in that case perhaps it is better to do all process in the darkness (inside the tank). For the moment don't think it is a control factor, just develop completely and if wanting a lower density expose more or develop more in the first development.

11) Well, you are almost done, a fixer bath will remove any remaining silver halide if development was not complete, in theory it's not necessary if second development was to completion, in practice it cleans well the emulsion, I guess.

________

Some tips:

1) Permanganate bleaching did not work to me for HP5+, I got a black slide.

2) Dichromate worked bleaching well, but you have to handle it with care as it's toxic, no problem if handled with care. Mix it with water outdoors to prevent generating dust. Absolutely prevent any spill, mix it with diluted developer before disposal, then it will turn green (from orange) pointing that most has been converted to another oxidation state, way, way safer.

3) To have real control with slides you should learn well Beyond the Zone System book, in the full process you may want to make a selenium toning for the finishing, you should make a calibration with different exposures and 1st development times with the toning included, then you plot the curves to see what happens with contrast and density, so you will be able to know the densities of the shadowsand of the highlights, or of any spot in the scene, then you may pick the exposure delopment you want.

Anyone can make negatives... you anyway can change a lot the image in the printing on in Ps, but nailing slides... this requires a photographer !!!

So for slides you need a good deal of metering/process control. This is an extra effort, but this will be very rewarding in terms of personal joy, and also it it will teach you about what's accuracy in a photographic process.


4) You may start with the Foma 100R film and the Foma reversal kit, it will work straight, so it's a good way to start, then you may go to a custom process.

https://www.fotoimpex.com/films/foma...che=1546786152
https://www.fotoimpex.com/chemistry/...s8-1x16mm.html


Sorry if it was a too long answer, feel free to ask anything or to PM on any doubt.

Regards,
Pere

An slide I love: https://www.flickr.com/photos/125592...posted-public/

[Tin Can]

Pere, thank you for a thorough B&W reversal method with baby steps!

I will be trying this.

Really good advice to test with 35mm.

[Pere Casals]

I will be trying this.

Randy, do not take long... That's worth...

[interneg]

A friend of mine omits a solvent from the first developer and instead tweaks exposure and first development, and also adds adds fixing step at the end (also present in the above worflow). I've seen his transparencies on Adox Silvermax and they really are excellent.

I'd be interested to know how he alters exposure & 1st dev - given the intentionally higher silver content of Silvermax for reversal, I suspect it may reverse better without extra solvent than a more 'normal' negative film. I also remember reading somewhere that a post exposure flash can do much the same thing as the added solvent, but that might just be crossed wires in my brain!

[tgtaylor]

This thread: https://www.largeformatphotography.i...sing-with-D-11 provides an accurate description of my initial attempts at reersal processing which ended with excellent results. It turned out that Dr5 made a Scribner's error in the formula.

Thomas

[koraks]

I'd be interested to know how he alters exposure & 1st dev - given the intentionally higher silver content of Silvermax for reversal, I suspect it may reverse better without extra solvent than a more 'normal' negative film.

He did do some testing with other film (I think it was Foma 100) before trying it on Silvermax. As I recall, he mentioned using Silvermax for this because of its supposedly high silver content, but also just because he got a roll of it and decided to use part of it for this project. I think he rates the film at 160. I'd have to ask him the specifics of his process, but it was by no means arcane or complicated.