BW reversal options

Mike Wilde · Jan 11, 2011

dafy said:
I can't imagine getting any mids with Dektol/QUOTE]

The first developer sets the tone and shape of the curve. The second developer as I understand it develops everything that is left to develop against what the first developer left as it's silver profile.

Pan F as I know it is a low speed conventional grain film.

holmburgers · Jan 11, 2011

If the first developer sets the tone and curve, why does Dektol work?? *CONFUSED*

I've never developed film in paper dev, but I would imagine it would not come out very pleasant. Or am I wrong.

dafy · Jan 11, 2011

Fred-can you please share your experience with R100 as a positive?

It might be worth trying to substitute Dektol in the first stage with whatever the PF equivalent of Technidol is for ATP 1.1. But as PanF is conventional that may be the way to go.

dafy · Jan 11, 2011

Frank - why not? I appreciate the grain or lack thereof with all the positive films I've tried and if I'm reading all of this correctly a combination of slow film plus reversal processing will allow me to get nicer prints from my scans...

frdrx · Jan 11, 2011

Dafy, I've always processed my R100 as a positive. If you want me to post some scans, I don't think it's worth it because they talk more about the properties of the scanner I have at hand than the film itself. My scans together with my image manipulation abilities simply don't do justice to the slides. Here's one nonetheless (model release not signed):

I use the film primarily for candids that surprise rather than deliberately composed images, but I also like to shoot scenes from the same spot with two bodies (one loaded with Fujichrome, and one with Fomapan R100). This creates lovely transitions when I project slides with a dissolve projector.

fschifano · Jan 11, 2011

dafy said:
Frank - why not? I appreciate the grain or lack thereof with all the positive films I've tried and if I'm reading all of this correctly a combination of slow film plus reversal processing will allow me to get nicer prints from my scans...

Because you can do the same thing by scanning a B&W negative. Color slides from the E6 process show very little to no grain because there is no silver left in the emulsion after processing. The same is true for C41 negatives. But B&W reversal processing leaves silver in the emulsion and you wind up with a relatively high contrast image.

dafy · Jan 11, 2011

Dekuji, Fred. Jmenuji se Shawn - Dafy's just my name on the forums. Mluvim Cesky, ale jenom trochu. Moje nejlepsi kamarad je Ceska...or she used to be anywasy, we don't talk much now. I hope you know what I'm trying to say lol!

Is the R100 positive developing available as a kit? That's one of the things that led me here in the first place.

How grainy is it compared to say, well, for simplicity Tech Pan vs TMX vs TMY?

dafy · Jan 11, 2011

I like high contrast, Tech Pan is/was my favourite film. But you are saying the silver is different than E6 (or I assume Scala as well). So I need to ask then, does processing BW negative film as a positive reduce the grain? Sorry lots of info to wrap my head around in the last few hours.

Shawn

fschifano said:
Because you can do the same thing by scanning a B&W negative. Color slides from the E6 process show very little to no grain because there is no silver left in the emulsion after processing. The same is true for C41 negatives. But B&W reversal processing leaves silver in the emulsion and you wind up with a relatively high contrast image.

fschifano · Jan 11, 2011

dafy said:
I like high contrast, Tech Pan is/was my favourite film. But you are saying the silver is different than E6 (or I assume Scala as well). So I need to ask then, does processing BW negative film as a positive reduce the grain? Sorry lots of info to wrap my head around in the last few hours.

Shawn

That's the point. There is no silver left in E6 or C41 film at the completion of processing. The image in these films is made up entirely of dye clouds, whereas the image in a reversal processed B&W film has the image made up of silver grains.

michaelbsc · Jan 11, 2011

dafy said:
I like high contrast, Tech Pan is/was my favourite film. But you are saying the silver is different than E6 (or I assume Scala as well). So I need to ask then, does processing BW negative film as a positive reduce the grain? Sorry lots of info to wrap my head around in the last few hours.

Shawn

fschifano said:

Because you can do the same thing by scanning a B&W negative. Color slides from the E6 process show very little to no grain because there is no silver left in the emulsion after processing. The same is true for C41 negatives. But B&W reversal processing leaves silver in the emulsion and you wind up with a relatively high contrast image.

Click to expand...

As Chris pointed out in post 4, the larger grains are more sensitive so they develop first. Then you wash away those larger grains in the bleach step, and when you fog to get the reverse image there are fewer of the larger grains left over.

So in effect you do get some grain size reduction in the final image, but I doubt it is as noticeable as with old films. The modern film is probably much more consistent in grain size than something like Tri-X from 40 years ago.

Antonov · Jan 12, 2011

fschifano said:
That's the point. There is no silver left in E6 or C41 film at the completion of processing. The image in these films is made up entirely of dye clouds, whereas the image in a reversal processed B&W film has the image made up of silver grains.

Wait, no silver at all? Not even silver halides? What about B&W negative?

michaelbsc · Jan 12, 2011

No. No silver is left. The image is formed by the dyes.

B&W has the silver left in it. It forms the image in those films.

Existing Light · Jan 12, 2011

holmburgers said:
I've wondered the same thing. I believe that it is faster, but indeed, couldn't any developer work?

I read that the purpose of the first developer is to develop the negative image to "gamma infinity". What exactly does this mean? Doesn't one have to worry about fogging in the 1st dev?

I guess any developer would work. My first developing step is 12 minutes with paper strength Dektol; developing times with regular developer might be insanely long. Also, the film, from what I understand, has to be developed to a higher Dmax than regular B&W negs, so the strong first developer might be nessesary for that. I dont see why developing with Xtol for 90 minutes (a guess I pulled from my ass. I dont know how long it would take to develop in Xtol ) wouldnt do the same thing, but why? Remember, I am doing constant agitation for that 12 minutes, so imagine doing constant agitation for 30 minutes, 45 minutes, or an hour or more with regular developer. If you have a motorized agitation contraption, that might not be a problem, but I use my arms

If anyone is brave enough to try developing in regular developer, go ahead and post the results. I'm curious, but I dont have any regular film developer now since I've been using dektol for slides for the last 8 or 9 months. I donated my last bit of Rodinal and a little bit of Arista and Slavich paper to the photo department since I had no intention of using Rodinal or printing for a while

As for fogging, I see no fogging; my highlights appear to me to be unfogged. I believe I read that the sodium thiosulphate helps with fogging, but since I can see no fogging in the projections or the slides, I'm not going to worry with it. If you'll be scanning, that should be easily fixed in your computer's editing software. Note that I only have experience with FP4+ and Arista 200. I quit using Arista because I kept having problems with pinholes, but it appeared fog-free, too. Other films might have fogging issues. IDK.

I'd like to note that I'm not using a densitometer; I'm going by just looking at the slides on a light table and projections. Maybe a densitometer can pick up slight fogging. If there's any, to my eyes it seems to be negligible

I'm not sure what gamma infinity means. I've heard the term thrown around a few times, but never figured out what the piss it meant. Contrast or brightness, maybe?

holmburgers · Jan 12, 2011

Ok, this thread has made me finally get off the pot, so to speak, with my reversal processing.

I have a few questions though.

First, I'm going to use a Potassium Dichromate bleach with a Sodium sulfite clearing bath. I've heard that it is important to use sulfite with dichromate and metabisulfite with permanganate.

I also plan to make a two part solution; A) K-dichromate at ____(??) g/L and part B) a 20% solution of conc. sulfuric acid. Add equal parts A & B. So, a, how much K-dichromate and b if I have 48% sulfuric acid from PF, how do I get a 20% solution in part B, thus leading to a 10% solution of conc. sulfuric acid in the final mixture? And is 10% a good final concentration? Wheww...

I notice that the above formula uses no sulfuric acid. Is this normal? Most formulas I've seen use it, but just curious. Anyways, I'm guessing that using sulfuric acid would negate the need for a stop bath.

For clearing bath; 100 g/L of Sodium Sulfite.

Developers will be Dektol 2:1 and HC-110 respectively. An online account says dilution F of HC-110, I don't know why that one over dilution B, perhaps just to save chems? Develop for standard recommended time?

This is kind of a conglomeration of the Ilford recommendations and said 'online account', but I'm going to corroborate all this with as many formulas as I can find today. Though, if anyone can help me out here, that would be schweeeet.

I like to get 2nd, 3rd and 4th opinions

***

Here are all the reversal formulae I could find in the APUG articles section:
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Existing Light · Jan 12, 2011

holmburgers said:
Ok, this thread has made me finally get off the pot, so to speak, with my reversal processing.

I have a few questions though.

First, I'm going to use a Potassium Dichromate bleach with a Sodium sulfite clearing bath. I've heard that it is important to use sulfite with dichromate and metabisulfite with permanganate.

I also plan to make a two part solution; A) K-dichromate at ____(??) g/L and part B) a 20% solution of conc. sulfuric acid. Add equal parts A & B. So, a, how much K-dichromate and b if I have 48% sulfuric acid from PF, how do I get a 20% solution in part B, thus leading to a 10% solution of conc. sulfuric acid in the final mixture? And is 10% a good final concentration? Wheww...

I notice that the above formula uses no sulfuric acid. Is this normal? Most formulas I've seen use it, but just curious. Anyways, I'm guessing that using sulfuric acid would negate the need for a stop bath.

For clearing bath; 100 g/L of Sodium Sulfite.

Developers will be Dektol 2:1 and HC-110 respectively. An online account says dilution F of HC-110, I don't know why that one over dilution B, perhaps just to save chems? Develop for standard recommended time?

This is kind of a conglomeration of the Ilford recommendations and said 'online account', but I'm going to corroborate all this with as many formulas as I can find today. Though, if anyone can help me out here, that would be schweeeet.

I like to get 2nd, 3rd and 4th opinions

The link I posted gives directions for mixing up both the Dicromate bleach and clearing bath and the Permanganate bleach and clearing bath. If you can get your hands on sulfuric acid, this quote comes straight from the article I linked a number of posts earlier: "Fritz Brown suggested on photo.net that 55g of sodium bisulfate can be used instead of the sulfuric acid. " I've not tested that; I use the permanganate bleach and the metabisulfite clearing bath. I'm not much help with getting the solution percentages right; perhaps someone better in math can help (I'm no chemist. I just follow the recipes and suggestion I find here on APUG ).

For the developing steps, I'd personally recommend saving the Dektol and reusing it as the second developer. I do that with no problems. The way I understand it, the first developer is the important one; the second one is done to completion, so it doesnt really matter what you use or how long you do it as long as it's developed enough. If you wanna mix up a Dektol first developer and an HC-110 second developer, go ahead; maybe you'll get a plesant suprise I'm too cheap and stubborn to find on my own

I think the reason some formulas give substitutions for sulfuric acid is that it's kinda hard to get. It is possible to make explosives with it, though I'll admit I have no idea how to do it. It's probably best I'm left in the dark in such matters; I almost burned the neighbor's field down once when I cut open some fireworks (those mortar thing you fire out of a tube) and filled a water bottle 3/4 the way full with the contents, and ignited it. I will admit I was young and stupid.... but now I'm older and stupid (Luckily, we had a few hundred feet of water hose and a faucet on that side of the house, so it got put out before it could spread too far. )

holmburgers · Jan 12, 2011

Hahaha, wow! I had a similar experience; burning down a 1/4 acre or so of creek bottom when I was about 8. But hey, it cleared it out and was much nicer afterwards..

I might try the Dektol for the 2nd dev; indeed it seems fine considering all the literature. I'll be curious if anyone perks up with contrary info.

I've settled on 7 g/L of K-dichromate and if concentrated sulfuric acid is 95-98% according to wiki then a 48% solution would require 20mL/L to get a 10% solution.... I think.... right? Anybody?... Bueller?...

Sulfuric acid isn't honestly hard to get; PF has it, they use it in car batteries, etc.

Na-Sulfite at 100 g/L.

How well do these solutions keep? The reason for an A/B solution of bleach is shelf life, how 'bout the clearing bath?

Oh, and honestly, how necessary is a fixer, since all the undeveloped silver should be gone anyways?

Chris Douglas · Jan 12, 2011

I'm impressed at all the interest in this. I use the sulfuric acid, dichromate bleach but if you aren't the careful type, I wouldn't reccomend it. I use the formulas in the darkroom cookbook. I believe the developer is D76 with some thiosulfate. This process works very well with plus-x exposed at EI 500.

michaelbsc · Jan 12, 2011

Existing Light said:
I think the reason some formulas give substitutions for sulfuric acid is that it's kinda hard to get.

You should be able to get it at an auto parts store as battery acid.

holmburgers · Jan 12, 2011

Chris Douglas said:
...but if you aren't the careful type, I wouldn't reccomend it.

My plan is to reversal process 4x5" film in deep tanks. Indeed, I'm concerned about the complete darkness and handling of tricky chemicals.

What is the recommened way to do such processing, safetly, with sheet film? I'm tempted and plan to buy one of those Paterson 3-reel 4x5" holders (MOD photographic, see the thread....) but in the meantime I have trays or deep tanks.

dr5chrome · Jan 12, 2011

..wouldn't recommend reversal processing by tray.
other Qs in this thread: Be sure you use quality materials or you will be dealing with terrible inconsistencies.

A reversal B&W result [contrast & dynamic range] is variable by the entire process - not just the 1st developer. 1st, 2nd, bleach, film-type, & procedure all can change the outcome.

..the scala process is a light reversal designed process - sub-par design in my opinion. The film is a good-film however.

dw

holmburgers said:
My plan is to reversal process 4x5" film in deep tanks. Indeed, I'm concerned about the complete darkness and handling of tricky chemicals.

What is the recommened way to do such processing, safetly, with sheet film? I'm tempted and plan to buy one of those Paterson 3-reel 4x5" holders (MOD photographic, see the thread....) but in the meantime I have trays or deep tanks.

Ian Grant · Jan 12, 2011

Not all older reversal processes went to completion in the 2nd developer after re-exposure, and some used variable second exposure as part of the overall process control. Pre E6 Kodak Ektachrome while using a light fogging re-exposure (e2/3 - E4 used a fogging agent) also used a variable 2nd development time for push/pull processing.

There's so many more variables that can be used to control the final output with B&W reversal than first meets the eye.

Ian

holmburgers · Jan 12, 2011

Would you guys care to share, in general terms, how things can be affected in each step?

This is the fun of RP; the variables!

michaelbsc · Jan 12, 2011

holmburgers said:
Would you guys care to share, in general terms, how things can be affected in each step?

This is the fun of RP; the variables!

Yes. Please!

Existing Light · Jan 12, 2011

holmburgers said:
Would you guys care to share, in general terms, how things can be affected in each step?

This is the fun of RP; the variables!

I'll second this request. I've been getting results I'm perfectly happy with the process I've been using, but knowing how each step can change the end product would be good creative knowledge. The only interest I have right now in adjusting variables (and that can and will change later on) is in pushing and pulling. Wouldnt that require a change in the first developer only, or would I have to adjust the bleaching, clearing, and second developer as well?

In reguard to using battery acid from auto stores, how does that compare to the stuff PF sells? The battery acid is more dilute, in the range of 50%, while the PF stuff is around 98%, right? What about impurities in regular battery acid that might not be present in the PF acid? And doesnt PF require a DEA license to be able to purchase sulfuric acid?

dafy · Jan 12, 2011

I suppose one good way to start would be to take a roll of film, say 12 images then a few blanks so you can cut it in the dark, then exactly the same images. Expose both sets the same (bracketing, and I mean the same image over and over) and develop set A as a neg, and set B as a pos, following some set of instructions for development as many posts here have given instruction for. Find the best of each, compare, and tweak.

One roll of film if you make notes and changing development variables from there...that's probably what I'll do. Still deciding on buying chemicals or a kit, but it seems to me a kit is kinda useless unless you're using the proper film, ie tmax. So though a more dramatic buy-in, chemicals are probably better.

BW reversal options

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