reversal processing of Black&White paper

For fun I've been trying to reverse process black and white paper. This would mean putting enlarging paper in the camera, expose, and process to get a positive image.

The process seems simple, and is similar to reversal processing of black and white film- develop, bleach, clear, re-expose to white light, develop, then fix.

I got the process details from an old RIT paper. Here's the process (I assume it uses RC paper):

1st developer 30-60 sec
rinse 30 sec
bleach R-9 30-60 sec
rinse 30 seconds
Clear CB-1 30 seconds
Rinse 30 sec
Expose to light (40 watt bulb for 5-10 sec at 12 inches)
2nd developer
fix as usual

R-9 is 9.5 g Potassium Dichromate + 66g Sodium Bisulfate into 1L

CB-1 is 90g Sodium Sulfite into 1L

I follow the directions and get an almost solid black print! I know the initial exposure is close to correct because I can see the negative image come up in the first developer tray.

It is as though the print never got bleached, though I could see the bleach work in the tray. I tried lengthening the time in the bleach, then reducing the time in the bleach. Still all black. I tired varying the amount of time of the re-exposure to white light, still all black.

When I say almost black, I mean it is all black except for a few spots that were specular highlights in the scene.

Can anyone clue me into what I might be doing wrong? Or what I could try?

According to the text, if I had some sodium sulfide I could skip the re-exposure to white light and use Sulfide Redeveloper T-19.

Thanks,
Keith Ostertag

Actually, there are two possible solutions that come to mind.

The paper is probably too slow (not fast), and needs a LOT more exposure, or the first development time is too short and does not develop all of the silver. A third possible answer may lie in the fact than many reversal first developers require a silver halide solvent to kick them off. This latter thought may be way off, and people differ on the effectiveness of solvents on reversal processing like this.

In every case I have tried it, I have had to use about 2 - 4 stops more exposure than appear to be needed to get a good negative image. You will probably get very high contrast and may have to use a grade zero paper for a good print.

PE

WAG or an actual photographic engineer. You be the "decider"

Is your bleach rehalideifying (can never remember that word) the silver? Either that or you need more original exposure like PE said, although I would assume that if you saw an image at first SOMETHING would appear in the final print.

Just turn on the lights. There's no need to be super-scientific about it.

The bleach must have NO halide in it or you will get no image at all. It must be a dichromate-sulfuric acid bleach or a permanganate bleach. The word is "rehal" bleach. You must not use one in this type of situation.

PE

keithostertag said:

When I say almost black, I mean it is all black except for a few spots that were specular highlights in the scene.

Can anyone clue me into what I might be doing wrong? Or what I could try?

Thanks,
Keith Ostertag

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You may need to give a flash exposure after the image exposure to reduce the density. Remember there is more silver than is needed to make a photograph. You have to remove the this extra silver by first development and then bleaching it away just like you are doing to the negative image first obtained with the camera.

Are you using variable contrast paper? If so I would expect black as there would be some under exposed silver. The bleach removed the exposed silver, but there would still be unexposed silver.

Try graded paper or simpler, freestyle has direct reversal paper and develop as normal.

Thanks for your responses. I forgot to say that the instructions say to use a high contrast developer, but then goes on to say that Dektol 1:1 would "probably" work. Well, I fugured that if Dektol would work then my LPD would work... my mistake. I will try a high contrast dev and if that doesn't work I will try adding some hypo. I will post the results in a day or so. Keith.

Keith, there's a thread about the old style B&W photo-booths (there was a url link here which no longer exists)the use Reversal processed paper.

Note the formulae are only whats stated on the MSDS's or somewhere showing the main ingredients.

I suspect you are using too weak a developer and also under developing, as well as maybe exposure issues. Most First developers for reversal processing are quite contrasty and development is total, that means all exposed silver halide is developed. You can get a good idea of the papers camera speed by making Paper negatives using the same developer, then move on to reversal processing and fine tune the speed. As a rule of thumb a print developer is usually used at up to twice the normal strength for reversal processing of film so for example 1+4 instead of 1+9

Back in the early 70's I saw some superb B&W prints made by the reversal process, so I know it's capable of great things.

Ian

Pe; back when R printing was around I was considering modifying the process to accept B&W RC paper [light reversal]. do you think a modification of the R process would be a better reversal B&W printing solution?

dw

Photo Engineer said:

Actually, there are two possible solutions that come to mind.

The paper is probably too slow (not fast), and needs a LOT more exposure, or the first development time is too short and does not develop all of the silver. A third possible answer may lie in the fact than many reversal first developers require a silver halide solvent to kick them off. This latter thought may be way off, and people differ on the effectiveness of solvents on reversal processing like this.

In every case I have tried it, I have had to use about 2 - 4 stops more exposure than appear to be needed to get a good negative image. You will probably get very high contrast and may have to use a grade zero paper for a good print.

PE

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dr5chrome said:

Pe; back when R printing was around I was considering modifying the process to accept B&W RC paper [light reversal]. do you think a modification of the R process would be a better reversal B&W printing solution?
dw

Click to expand...

If you look at the (there was a url link here which no longer exists) first developer you'll see this is actually a simple colour developer. Also some of the early additive colour processes used similar developers even though there's no dye coupling taking place.

As I said in a previous thread sometimes when you look back it gives you clues to other avenues for going forward

Ian

One thing not mentioned is the sulfite bath, CB1. This is what keeps the negative image from redeveloping as well as having the proper bleach, which it appears you do. Maybe a longer time in CB1 would help or a higher concentration?

glbeas said:

One thing not mentioned is the sulfite bath, CB1. This is what keeps the negative image from redeveloping as well as having the proper bleach, which it appears you do. Maybe a longer time in CB1 would help or a higher concentration?

Click to expand...

No, that's wrong the negative image has already gone the bleach has dissolved the exposed & processed Silver which was converted back to Silver. The sulphite removes the staining caused by the bleach bath if a dichromate bleach is used, metabisulpite does the same if a permanganate bleach is used.

The sulphite/metabisulphite will also act a bit like HCA to help remove the last traces of the bleached silver from the emulsion.

Yes it's a vital step but if you left it out you'd still get an image, although possibly very slightly degraded.

Ian

This might be an option Keith and David EFke Direct Positive paper from Freestyle.

Just found the notebook I started in the mid 70's, and there's a scribbled line at the end of the two B&W reversal Formulae I'd tried. "B&W paper can be reversal processed with any normal print developer as the first developer". I guess the word normal means clean working & not warm toned. Also says G-14, not sure what that is. I've seen an a piece in a book about making B&W prints from colour transparencies and I'm sure that was similar, develop as normal then rinse well, and go through the other stages of the reversal process. I What ever the book is it's in storage in the UK at the moment. 'm sure Kodak made suggestions for how to produce B&W prints from slides as well, these would be equally applicable to a B&W transparency.

Ian

Regarding the Pathescope and R processes, p-phenylene diamine itself is a very poor color developer but a good, albeit weak, low contrast B&W developer. It was in common use about 100 years ago or thereabouts. The R process used a rehal bleach and would therefore be unsuitable for reversal B&W and changing it would render it so totally different it would be a different process entirely.

As for the clearing bath, it is used to reduce all of the excess dichromate left in the film (or permanganate for that matter depending on which bleach you use) and prevent carryover into the second developer. If you do that, the alkali mixed with the oxidant/reductant causes severe image problems.

All B&W and color processes with dichromate, permanganate, ferricyanide and other strong bleaches, whether B&W or color, require a clearing bath after the bleach and often before the bleach as well to remove oxidants and reductants and prevent stain formation or unwanted image problems.

PE

Photo Engineer said:

Regarding the Pathescope and R processes, p-phenylene diamine itself is a very poor color developer but a good, albeit weak, low contrast B&W developer. It was in common use about 100 years ago or thereabouts.
PE

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It was still common until the 1980's and beyond, but only in B&W developers, it's in some Edwal Developers, and of course both Sease and Crawley used it as well. Some current commercial B&W developers use a derivative.

Ian

PE;
my reference was to 'R' "procedure" it self, naming the use of an R-processor.

Of coarse the color chemistry would not function with B&W material, I am familiar with the R-color process.

I have access to an old R machine. Idea's on where to start for bath replacement for B&W paper? I am not so sure dichromate is the best route for paper. [sorry, not interested in grants opinion, his post are blocked any way, but he is welcome to reply to others ]

dw

Photo Engineer said:

Regarding the Pathescope and R processes, p-phenylene diamine itself is a very poor color developer but a good, albeit weak, low contrast B&W developer. It was in common use about 100 years ago or thereabouts. The R process used a rehal bleach and would therefore be unsuitable for reversal B&W and changing it would render it so totally different it would be a different process entirely.

As for the clearing bath, it is used to reduce all of the excess dichromate left in the film (or permanganate for that matter depending on which bleach you use) and prevent carryover into the second developer. If you do that, the alkali mixed with the oxidant/reductant causes severe image problems.

All B&W and color processes with dichromate, permanganate, ferricyanide and other strong bleaches, whether B&W or color, require a clearing bath after the bleach and often before the bleach as well to remove oxidants and reductants and prevent stain formation or unwanted image problems.

PE

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dr5chrome said:

PE;
my reference was to 'R' "procedure" it self, naming the use of an R-processor.

Of coarse the color chemistry would not function with B&W material, I am familiar with the R-color process.

I have access to an old R machine. Idea's on where to start for bath replacement for B&W paper? I am not so sure dichromate is the best route for paper.

dw

Click to expand...

Your the expert on Reversal processing so why ask such simple questions.

Plenty of people haver used Bichromate bleaches for B&W papers and published their experiences.

Ian

dr5chrome said:

PE;
my reference was to 'R' "procedure" it self, naming the use of an R-processor.

Of coarse the color chemistry would not function with B&W material, I am familiar with the R-color process.

I have access to an old R machine. Idea's on where to start for bath replacement for B&W paper? I am not so sure dichromate is the best route for paper. [sorry, not interested in grants opinion, his post are blocked any way, but he is welcome to reply to others ]

dw

Click to expand...

It's sad that your negative attitude means people turn away from your DR5 process, and your company full stop.

You have a good service but you are also your own worst enemy. I have NEVER seen anyone complain about your processing but only about your attitude.

You have competition you'll soon have more, but don't over hype your services.

Ian

dr5chrome said:

PE;
my reference was to 'R' "procedure" it self, naming the use of an R-processor.

Of coarse the color chemistry would not function with B&W material, I am familiar with the R-color process.

I have access to an old R machine. Idea's on where to start for bath replacement for B&W paper? I am not so sure dichromate is the best route for paper. [sorry, not interested in grants opinion, his post are blocked any way, but he is welcome to reply to others ]

dw

Click to expand...

Well, then, it has become obvious to you that I know nothing about the "R" processor only the color "R" process itself and got them confuse having no information on hte former.

PE

not what i implied at all PE. you may imply what ever you wish. just trying to strike up a conversation. lets forget I brought it up.

best.

dw

Photo Engineer said:

Well, then, it has become obvious to you that I know nothing about the "R" processor only the color "R" process itself and got them confuse having no information on hte former.

PE

Click to expand...

dr5chrome said:

not what i implied at all PE. you may imply what ever you wish. just trying to strike up a conversation. lets forget I brought it up.

best.

dw

Click to expand...

Sorry, no implication implied or expressed. I simply know nothing about the "R" processor and that is all I can say..

PE

To report back regarding the original query: With further tests I was able to get the reversal process to work just fine. It turns out that my exposures had been underexposed by a stop or so.

At first I got what looked like a proper negative exposure (processed normally before bleaching) using a meter reading and adding 3 stops. That resulted in an almost completely dark product. Here's what finally worked for me using Agfa RC paper: using a meter I got the exposure for ASA 8 (the lowest asa my meter registers), then added about 4.5 stops. My final working exposure was 1 minute at F11 using tungsten lights.

The final product was a bit contrasty using either developer, but I have yet to try it with a low contrast subject. And of course, the paper is not panchromatic. My original intention was to use this process in order to use photo paper in my 8x10 camera to save money. Now I am thinking to use it with 16x20 paper in a 16x20 pinhole camera!

Thanks to all who answered my initial query, and I hope this writeup will help others attempting the process.

For the sake of the archives, I found that I did not need to add the solvent (sodium thiosufate) to the first developer as some had suggested. I tried D-19 (a high contrast developer) with the added solvent and got pretty much the same results as by using my regular paper developer with nothing added. I used LPD for both my first and second developers, 1:1 with water, and I assume you could use Dektol or other developers with similar results.

You can get details of the B&W paper reversal at:
http://members.iinet.net.au/~forbes/reversal.html

Another page that is really helpful is Donald Quall's page:
http://silent1.home.netcom.com/Photography/Dilutions and Times.html
along with many other formulas and tips.

keithostertag said:

It turns out that my exposures had been underexposed by a stop or so. ... I found that I did not need to add the solvent (sodium thiosufate) to the first developer as some had suggested.

Click to expand...

That mimics my experience - that you have to overexpose the bejesus out of the material. I imagine if an area is to be white in the final print then it is necessary to first turn every particle of silver halide black so it can be bleached away. My work with making enlarged negatives from Arista lith film required enough exposure to turn the film jet black - detail could only be seen by shining a light through the film. When in the bleach the darkest areas of the negative went quite transparent and remained that way when the film went into the second developer.

I found that thiosulfate in the developer just 'fixed' away the image before the developer could act.