Fompan R100 Reversal First Developer

[Athiril]

Athiril submitted a new resource:

(there was a url link here which no longer exists) - Fompan R100 Reversal First Developer

Hi all,

Thought I would share this, since I found info on a good working first developer for Fomapan R100 impossible to come by, since we had some to process for a customer, I had to come up with a working developer.

First off, any formulation using a solvent like sodium thiosulphate or thiocyanate, forget it, take it out. You can't use a solvent to clear the highlights on Fomapan R100, it will simply give you muddy dMax at best, you need no reduction of dMax through any significant...

(there was a url link here which no longer exists)

 

[Mustafa Umut Sarac]

Hello Athiril ,

If it wouldnt be difficult , could you please document the recipes after your first development step. There is too much information on net and I dont know what is good or not . Sulphuric acid is easier to find here.

ps. I have that film in regular 8 cut in Bolex and many houses reported that they can not process clean with Kodak process.

Thank you,

Umut

 

[Athiril]

The rest of the process is regular B&W reversal, it's only incompatible with the first developer used for other films, I don't seem to be able to find the edit option for the article.

Anyway.

It's 5m at 27 celsius for first developer as described above, followed by a stop bath, not a rinse. It's light safe at this point, you can open the tank.

Then wash for 1 minute.

Then bleach, it's just a standard dichromate/sulphuric acid bleach, I don't even measure it out since it's so reliable (unlike permanganate), I just put a few drops of concentrated acid in with a spoon ful of dichromate, I reuse mine after filtering, though it's easier to use one shot, as the handling of dichromate is easier that way and it's cheap anyway as you need little of it.

Bleaching of this film takes longer than other B&W films for reversal because of the extra silver layer in the film, you'll know by inspection when it's done, as the silver layer will clear, revealing the negs, which will be black in colour, then the negs will clear and you'll be left with yellow looking film. Make sure to agitate the bleach every 2 minutes (or 1 minute if you prefer), less you find some spots not fully bleached on the film where you can't see.

Pour out the bleach, and rinse the out the tank/film with water. Then put in your clearing bath (I just use a spoon of sodium sulphite in water), clear for 1 minute is adequate.

Wash the film for 2 minutes.

Now you must perform the reversal step, you can use any normal reversal step, exposure to light, or chemical reversal, your choice, for light reversal, take the film off the reel, and put it back on, I suppose you could run a strong torch over the reel on both sides should be adequate to get it all, but I like to make sure it's fully exposed. Plus take it off the reel at this point will let you inspect the film entirely to see if the bleach is completely done over the whole length of the film. Of course this may be a pain with a movie length of film, I know about 2 teaspoons more or less per litre of bleach of dichromate will clear before 10 minutes at 20c with per minute agitation, so I usually go a bit more than 10 min, you can use a warmer bleach temp too, with no issue, I think I did one lot at near 30 celsius. You can't really over do this step, unlike with permanganate bleach where it'll ruin your film if you do.

Now re-develop the film, use any developer, you can reuse the used developer from first step here if you wish, rodinal, print developer, etc. Your choice.

Rinse the film off, and fix for 4-5 minutes with rapid fixer, to make sure any undevelopable halide (eg silver iodide) is removed, so the film doesn't potentially get muddy with age.

Now wash the film like you would with any other process, use a wetting agent, and hang to dry.


Permanganate Bleaches: I can't stand them, they always damage my film every single time, no matter how careful, low enough temperature, right amount measured out, with short enough time, so I would avoid this if possible and use a dichromate bleach, just treat the dichromate with respect and handle it safely, gloves, ventilation, etc.

Futhermore, Fomapan R100 takes longer to bleach than other films, which indicates that it may need either longer time, higher temp, or higher concentration bleach for permanganate, further increasing chance of damage, I know the kit uses it, but I still don't like it.

 

[Rudeofus]

About permanganate bleach: I've only used it once on some Ilford film and it did not attack the emulsion. There may be a profound difference between properly prehardened films (Kodak, Ilford, Fuji) and unhardened films (the rest).

 

[SMBooth]

Is there any problem using hydrochloric acid instead? its available from Bunnings.

 

[Ian Grant]

Is there any problem using hydrochloric acid instead? its available from Bunnings.

You can't use HCl because the chloride would convert the silver image form insoluble Silver chloride which wouldn't wash out before the reversal stage. You'd be forming a re-halogenating bleach, this is why Sulphuric acid is used as the Silver Sulphate formed during bleaching washes out of the emulsion.

Ian

 

[SMBooth]

OK, thanks Ian.

 

[Athiril]

OK, thanks Ian.

The bleach will then bleach the negative back to silver chloride using hydrochloric acid.

Anpros has Sulphuric Acid for sale you can use, you can also use sodium bisulphate, assuming there's no contamination of other chemicals like chlorides etc, one I bought off eBay must have had some chloride in it, as it only partially removed the negative, and the rest was bleached back but remained on the film.

I can dilute you a few mLs of concentrated sulphuric acid (as you need very little conc for it) in some water since you're in Melbourne.

Otherwise I got mine from http://anpros.com.au/

 

[SMBooth]

Thanks, that a nice offer. If I actually get around to trying this ill let you know. I just got some film from Blanco Nergo and forgot to add some R100. Looks a good way to make enlarged negative when shoot 35mm and your digital printing skills suck..

 

[Athiril]

Just a follow up - using a sodium carbonate and catechol only staining developer as the second developer, then followed directly with a regular developer just to make sure the remaining halide is driven to full completion of development to silver metal (had issues with this before when using just a staining dev as the 2nd developer), rinse and fixing in a regular acid fix (with some sulphite), the dMax reaches 3.16. Didn't do a strip with just a non-staining dev, but remember on Delta 100 I gained about 0.8 in dMax with this method.

 

[hired goon]

Hi -
Will be trying this shortly with Fomapan R100, and was wondering about a little more specifics on the bleach recipe. You mention relatively non-specific amounts, and am just looking for a tiny bit more clarification for myself, and perhaps others finding this thread at a later time. This may sound silly, but how big is your spoon - are we talking a teaspoon of Pot Dichromate? Rounded teaspoon? Also by a few drops of sulphuric acid, do you mean literally 3 drops? Lastly into how much water - I'm assuming a liter, but just making sure! The Sulphuric acid sold at photographers' formulary is 48% - will a few drops of that be sufficient, or is what you used a greater concentration?

I have a ton of darkroom experience, just not with this type of reversal film, so perhaps what you originally mention is totally good enough, and the amounts more or less just influences bleach step timing, I'm thinking, yes?

Thank you!

 

[iandvaag]

Athril, thanks for posting this and for all the work you put into formulating a usable developer. I know this sort of thing can take quite a bit of trial and error. I just wanted to post saying that I tried this developer for 9 minutes at 20 deg C and it worked quite well for me.