Fompan R100 Reversal First Developer
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 solvent action, it isn't like T-Max and others that get reversed and work well with a solvent. You'll get muddy slides. You need to clear the highlights instead, through developing power.
This is basically modified D-19, less sulphite, more hydroquinone.
|Sodium Carbonate (anhydrous)
Dilute 1:3, and process for 5 minutes at 27 degrees celsius, initial agitation first 30 seconds, 2 inversions per minute after.
Use a stop bath, not a wash/rinse after first developer, all tests were done with stop, to eliminate differences in different tap water and continued shadow development (reduction of shadow dMax) of different pH values etc.
Wash/rinse after stop for 1 minute. You may then process this as reversal as normal and bleach from there.
I use a potassium dichromate and sulphuric acid bleach because it is reliable, I have nothing but trouble with permanganate bleaches.
Australians: I've tried bisulphate in place of sulphuric acid before, and it failed me, it looks like it had some small amount of some kind of halide salts in it and formed a partial rehalogenating bleach.
You may get concentrated sulphuric acid in Australia from anpros (google it) shipped to you, for what you get it's not expensive for how long it will last. Not sure how much interstate shipping will be, I was pretty close to the place, so I may have gotten a less expensive hazard shipping fee. There may be other places that do this too. Also you only need a few drops of it since it's concentrated in your bleach, and be careful handling it!
Last edited by Athiril; 06-17-2014 at 01:29 AM. Click to view previous post history.
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.
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.
Last edited by Athiril; 06-17-2014 at 07:00 PM. Click to view previous post history.
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).
Trying to be the best of whatever I am, even if what I am is no good.
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.
Originally Posted by SMBooth
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The bleach will then bleach the negative back to silver chloride using hydrochloric acid.
Originally Posted by SMBooth
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/
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..
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.