An interesting foray into direct-positive reversal process with photo paper

[maritimephoto]

Hey folks! Long-time lurker, rare poster, overall big fan of this community and lover of analog photo

Some friends and I are working on some in-camera photo paper direct-positive prints. We got a process working from this outline here: http://sgwetplate.com/2020/05/film-photography-black-and-white-paper-reversal

The process:

1. Shoot in-camera with Ilford Multigrade IV Photo Paper (Satin)
2. Develop for 1min (we used both Ilford Multigrade Paper Developer and Quintol in two different trial runs for this, both with the same outcome below)
3. Wash in water bath 1min
4. Bleach in Potassium Permaganate + Sodium Bilsulfate solution for 5mins
5. Wash in water bath 1min
6. Re-expose to incandescent light for 30 secs
7. Re-develop (in same developer bath) in incandescent light for 1 min

The issue:

We only get a few good prints until the second re-development phase begins to max-out on its ability to produce blacks (even though subsequent initial developments still render true blacks). So by print 4, the re-development is not producing blacks, but interestingly, the initial development for the next print DOES produce deep, rich blacks. The same developer continues to work for initial development, but no longer works for the post-bleach step.

First picture:

Second picture (blacks already weakening, in waist area where they should be)

Third picture: (no blacks except in the corners, the darkest area of absolute black, the edges of the flash range)

Fourth picture (already unable to get any blacks at all anymore).

After this fourth picture, the fifth stil develops with rich blacks for the 'negative' initial image, but the second, re-development is inutile.


The confusion:

If the developer is contaminated enough to prevent blacks from forming during second development, why does it still produce full blacks during the first development of the next print, using the same developer?

I'm thinking it has to do with the potency needed for the second, re-development, after bleaching. The Initial Development is handling fresh, unbleached Ilford Multigrade paper. Only the areas hit by light (exposed silver halide) need to be reduced to metallic silver. The emulsion is clean, no weird chemistry in the paper, so even a partially oxidized developer still has enough reducing power to turn this silver halide into deep blacks?

But when the second development (post-bleach + re-exposure), the print has just been through bleach (KMnO₄ + Sodium Bisulfate), a quick unfresh wash, and a fogging exposure to light. The emulsion now contains: residual oxidizers (even if microscopic), possible manganese dioxide stain (from KMnO₄), and fully fogged halides (needs complete reduction across large areas).

So the first dev still works while second dev fails because the developer is partially weakened, but not dead. It can still handle the lighter job of initial development on fresh paper but it can no longer handle the heavier demand of reducing fogged halide after the bleach/fog steps. Does that sound right? We imagined it's like cooking on a camp stove with a dying propane tank. The first development is like frying an egg, and the second is like cooking a steak. We have enough heat left to cook the eggs, but not to fry steaks.

The potential solution?:

We're assuming redevelopment here is much more chemically demanding and that our re-development step is depleted by contamination.

If that's correct, is the logic step to try to reduce the residual bleach? For removal of potassium permaganate, we came across quite a few suggestions:

- Sodium metabisulfite (5%) solution
- potassium metabisulphite (3%) solution - (source)
- Sodium sulfite (5%).
- Kodak Cb-6 (sodium bisulfite anh. 15 g in 1 liter of water) - (source)
- combination of Kodak Hypo Clearing Agent stock solution + 15ml Kodak Indicator Stop Bath (concentrate). - (same source as above)
- we have some sodium bisulfite on hand. if mixed with water, would that work as a clearing bath? is that the same as "sodium bisulfite anh." of the Kodak Cb-6?

The question:

Is our assessment of the second development issue sound? If so, what is the best approach to clearing bath here. We'd like to use the same developer bath since we are running out of room.

 

[revdoc]

For clearing permanganate bleach, you want to use bisulfite to keep the solution acidic. Using sulfite will allow the formation of manganese oxide. The percentage solution isn't that critical; 1% is fine, and you should see it working as the brown stain fades. If it takes more than a minute, it's too weak. Be careful with this step; the bisulfite will act as a weak fixer if you keep the paper in it too long.

You also want much longer washes between steps. 4 minutes would be much better.

I'd also consider not re-using developer for subsequent prints. Reversal really beats up developers, and I find I only get consistent results if I use developer for one image only. I.e., I use it for first a development and a second development, then discard. You don't need to use a large volume, either... just enough to do the job.

(My experience with this is with enlarging negatives onto lith film. Paper might be different, but not by much.)

 

[koraks]

We'd like to use the same developer bath since we are running out of room.

Alternatively, use a small volume and mix fresh from a concentrated stock for every 2 prints or so. You only need something like 40ml of developer to develop 4x5" in a small tray.

I do agree that the problem is likely caused by bleach carryover into the developer.

you want to use bisulfite to keep the solution acidic

Not too acidic, however; below pH 4 the sulfite will start to turn into get sulfur dioxide gas.

 

[Alessandro Serrao]

I think the problem is not the permanganate carryover.
The problem resides in the clearing bath. It has the function of partially restoring the sensitivity of the film being bleached. In fact permanganic acid destroy all the film sensitivity.
Plus, the clearing bath must be potassium or sodium METABISULFITE.
Sulfite alone is not adequate at all.

 

[Alessandro Serrao]

Hey folks! Long-time lurker, rare poster, overall big fan of this community and lover of analog photo

Some friends and I are working on some in-camera photo paper direct-positive prints. We got a process working from this outline here: http://sgwetplate.com/2020/05/film-photography-black-and-white-paper-reversal

The process:

1. Shoot in-camera with Ilford Multigrade IV Photo Paper (Satin)
2. Develop for 1min (we used both Ilford Multigrade Paper Developer and Quintol in two different trial runs for this, both with the same outcome below)
3. Wash in water bath 1min
4. Bleach in Potassium Permaganate + Sodium Bilsulfate solution for 5mins
5. Wash in water bath 1min
6. Re-expose to incandescent light for 30 secs
7. Re-develop (in same developer bath) in incandescent light for 1 min

The issue:

We only get a few good prints until the second re-development phase begins to max-out on its ability to produce blacks (even though subsequent initial developments still render true blacks). So by print 4, the re-development is not producing blacks, but interestingly, the initial development for the next print DOES produce deep, rich blacks. The same developer continues to work for initial development, but no longer works for the post-bleach step.

First picture:
View attachment 395647

Second picture (blacks already weakening, in waist area where they should be)
View attachment 395648

Third picture: (no blacks except in the corners, the darkest area of absolute black, the edges of the flash range)
View attachment 395649

Fourth picture (already unable to get any blacks at all anymore).
View attachment 395650

After this fourth picture, the fifth stil develops with rich blacks for the 'negative' initial image, but the second, re-development is inutile.


The confusion:

If the developer is contaminated enough to prevent blacks from forming during second development, why does it still produce full blacks during the first development of the next print, using the same developer?

I'm thinking it has to do with the potency needed for the second, re-development, after bleaching. The Initial Development is handling fresh, unbleached Ilford Multigrade paper. Only the areas hit by light (exposed silver halide) need to be reduced to metallic silver. The emulsion is clean, no weird chemistry in the paper, so even a partially oxidized developer still has enough reducing power to turn this silver halide into deep blacks?

But when the second development (post-bleach + re-exposure), the print has just been through bleach (KMnO₄ + Sodium Bisulfate), a quick unfresh wash, and a fogging exposure to light. The emulsion now contains: residual oxidizers (even if microscopic), possible manganese dioxide stain (from KMnO₄), and fully fogged halides (needs complete reduction across large areas).

So the first dev still works while second dev fails because the developer is partially weakened, but not dead. It can still handle the lighter job of initial development on fresh paper but it can no longer handle the heavier demand of reducing fogged halide after the bleach/fog steps. Does that sound right? We imagined it's like cooking on a camp stove with a dying propane tank. The first development is like frying an egg, and the second is like cooking a steak. We have enough heat left to cook the eggs, but not to fry steaks.

The potential solution?:

We're assuming redevelopment here is much more chemically demanding and that our re-development step is depleted by contamination.

If that's correct, is the logic step to try to reduce the residual bleach? For removal of potassium permaganate, we came across quite a few suggestions:

- Sodium metabisulfite (5%) solution
- potassium metabisulphite (3%) solution - (source)
- Sodium sulfite (5%).
- Kodak Cb-6 (sodium bisulfite anh. 15 g in 1 liter of water) - (source)
- combination of Kodak Hypo Clearing Agent stock solution + 15ml Kodak Indicator Stop Bath (concentrate). - (same source as above)
- we have some sodium bisulfite on hand. if mixed with water, would that work as a clearing bath? is that the same as "sodium bisulfite anh." of the Kodak Cb-6?

The question:

Is our assessment of the second development issue sound? If so, what is the best approach to clearing bath here. We'd like to use the same developer bath since we are running out of room.

I think the problem is not the permanganate carryover.
The problem resides in the clearing bath that you've not used. It has the function of partially restoring the sensitivity of the film being bleached. In fact permanganic acid destroy all the film sensitivity.
Plus, the clearing bath must be potassium or sodium METABISULFITE and it's paramount, it's not optional.
Sulfite alone is not adequate at all.