Paper Negative Reversal Process (In camera positives)

[WayneStevenson]

I just thought I would share my results from testing some Ilford MGIV RC paper that I cut down into 4x5 to load into my cut film holders. With the intention of shooting at 8x10.

Besides Dektol and fixer, you need three other chemical solutions. Easily obtained, and inexpensive.

Bleach (2 part, mixed 1:1, makes very short life. I get several days before it stops working. It eventually goes clear but will still be useless with it's normal colour when it goes bad so always test):
Part A: 2g Potassium Permangnate to 1000ml water
Part B: 28g Sodium Bisulfate to 1000ml water

Clearing:
30g Sodium Metabisulfite to 1000ml water

Hypo Stock Solution:
32g Sodium Thiosulphate pentahydrate (Hypo) to 1000ml water

1)Developer Kodak Dektol stock with 3ml of hypo solution for 1:00 minute
2)Rinse
3)Bleach for about a minute
4)Rinse
5)Clearing solution for about a minute.
6)Rinse
7)Second exposure was done in daylight at sink while clearing and rinsing for only a couple minutes at most.
8)Second developer 20 - 30 seconds approx. Should be to completion.
9)Rinse
10)Fix (fixer of your choice)
11)Rinse
12)Dry.

[Harold_4074]

Interesting.

Years ago, I used to reversal-process Kodak Fine Grain Positive using a bleach/redevelop, but I don't recall ever seeing a formula for either which called for hypo in the developer. Is this your personal brew, or is there a resource of formulas like this somewhere?

I've often thought that a variable-contrast "film" would be interesting to play with (never mind the blue vs. green spectral response!) so it is interesting to know that VC paper behaves itself so well.

Thanks for posting!

[WayneStevenson]

The hypo addition was intended for film reversal to slow things down a bit (not my recipe). Things went pretty quick for me with regular Dektol that I added it as well. And it seems to work great.

I'd love to try this paper out with contrast grade filters as well. Heh.

[Emmanuel BIGLER]

Many thanks for sharing the recipe with us !

Regarding additives in Developer#1, I remember a recipe for B&W film reversal process recommended by MACO, where potassium thiocyanate was added "in order to dissolve silver salts" but I have no real idea of the actual mechanism.

I have found this page in German, for film reversal; "Kaliumrhodanid" is the same chemical as potassium thiocyanate.
http://www.fotografie-in-schwarz-wei...ntwickler.html

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Regarding filtering for contrast management : ss far as I've discussed with pinhole aficionados here in France using paper negatives, they prefer to use grade 0 or 1; so the idea is to filter to a relatively low contrast for the VC paper, not high contrast. But I have no idea how this combines with the reversal process.

Do you have an approx idea of the ISO rating ? Of course this will change behind a filter, but at least a starting value would be very helpful.
Thanks again !

[WayneStevenson]

You're welcome. Thanks for that bit of info on dissolving silver salts.

Oh. So sorry for that. I didn't realize I left that bit of information out. I spot metered the large light log in the pile. Shot the paper at ISO 3.

[Emmanuel BIGLER]

Shot the paper at ISO 3.

Thanks !
That's not really a much slower photo-sensitive medium than MACO SLIDE-DIRCT direct-positive ortho film, a very special film used to make direct copy of B&W transparent material.
This kind of direct-positive film existed in the Kodak catalog in the good old days, and is l available from AGFA-Mortsel [cut to size by MACO, but today no longer available in 4x5" sheets]. This special film is processed in a regular paper or film developer, no reversal process needed.
Speaking about direct-positive material, since ILFORD-HARMAN has on catalog a direct-positive paper, it would be nice to see if the reversal process of regular B&W paper yields better results in terms of tonal range and contrast management than ILFORD-HARMAN direct-positive paper.

[WayneStevenson]

I'm interested myself. I never had the pleasure of shooting any. But the ISO for it was suggested to be around ISO 3 as well. It's a shame that Ilford Switzerland shut the factory down that was manufacturing it. Hope Ilford Photo finds a solution to have it made again.

[gtmatias]

Clearing:
30g Sodium Metabisulfite to 1000ml water

Hello there,

Does it need to bem Sodium or potassium will do?

Thank you!

[gtmatias]

Hello,

Already done with success. Further investigation needed.

[valotus]

Hi!

I recently found this topic while I'm looking for solution to get paper base neutral. I'm using Ilford multigrade RC paper and doing reversal process with permanganate bleach and potassium metabisulphite wash. Have been doing this for several years more or less successfully, but now I have got problems with yellow-brownish tint on white areas.

I have tried to trace it in different steps of process, but the weirdest thing is that the stain mostly appears in last wash after fixing. Before that image seems to be neutral and if there is any slight colour, fixing will remove it. But then comes the ugly yellow-brownish stain...

Any help and hints are greatly appreciated.

J-P