So how hard would it be to remove this stuff? I've seen everything from using a wet sponge to some sort of pre-bath.
BTW I've seen comments that Fuji doesn't use any backing. Is that true?
Years ago I developed motion picture color negative film for still camera use. The only change to the processing sequence was to remove the REM jet backing after the stopbath. At this point the film can be exposed to room light. It's impractical to try to remove the backing before development (as is done during commercial processing) because you would have to work in total darkness.
At this point the prebath would be applied. The film would be removed from the reel and hung up and the back gently wiped with a sponge until all the carbon black had been removed. The sponge should be thoroughly rinsed after each pass. The film was wound again on the reel and the processing continued. Care must be taken that none of the carbon particles make their way to the emulsion side since they cannot be removed without damaging it. The prebath can only be used once since some carbon will always contaminate it. Only gentle brief agitation should be used in this bath since any carbon may be redeposited on the emulsion.
BTW, MP color negative is meant to be printed on color positive film which was a slightly difference set of color curves than color paper. Therefore it is impossible to get a perfect match. Either shadows will have a slight magenta cast or highlights will have a slight cyan cast. Or maybe it's the other way around -- it's been many years. Anyway, you cannot eliminate both.
Do you have a link/pointer for the pre-bath?
I'm willing to give it a go. The stuff is fairly cheap. I also figure worst case MP film will be around longer then still film.
Just to add a little to Gerald's post:
The developer softens the rem-jet resin and some carbon is likely to come out into the dev - so that should be used one-shot as well. I used a C-41 press kit intended for one-shot use - can't remember the make. PT did publish details of an alternative process intended to imitate ECN-2 I think. I could dig out the article, but I think that the back issue is still available.
The prebath that I know of consists of borax, sodium sulphate, and sodium metaborate. I'll get the quantities tomorrow morning if you want them. I'm not sure how important the sodium sulphate is - I've used it without.
With DIY processing the rem-jet removal step usually occurs after the fix (or blix) and before stabilisation, with washes before and after.
Sorry to mention it, but d*****l processing can sort out the colour curve mismatch.
Fuji MP colour neg didn't have carbon backing way back, but I'm fairly sure that it does have now. Their print film doesn't have it any more. Fuji information on the web isn't as complete as Kodak's so you have to phone them. Anyway, the last time I discussed this with a Fuji rep (a couple of years ago or so) I was told that only the positive film had been changed away from rem-jet type backing. I've never tried to process Fuji MP neg at home, by the way.
It's a while since I processed MP neg film at home - labs will usually process a few rolls for free if you are sending them your film, and Kodak gives cassettes of the stuff away if you ask for it, so it could be easy to try a roll or two.
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The formula for the pre-bath would be great. If I can run it after the stop that would protect my bleach/fix from the remjet. I use the developer one shot so that's not a worry.
I found a mention of running the developer for 3:45 instead of 3:15. One stop push I guess. Supposedly helps but of course no mention of why or what it helps.
Some one online has a chart of 16mm and 35mm films. It mentions all the Fuji films have a resin backing now.
You might want to try posting this on www.cinematography.com. John Pytlak, who is senior technical specialist, customer technical services at Kodak, is supremely helpful and generally responds very quickly to any post regarding motion picture film or processing.
I can't get into that website. The forums seem open to only registered users but it won't let you register-)
One pre-bath formula intended for use after the bleach or blix is:
Borax pentahydrate: 20 g
Sodium sulphate: 100 g
Sodium metaborate: 10 g
Water to 1 litre.
I can't remember having much contamination, if any, of the blix following an acid stop bath.
Traces of the resin can be removed from the base after drying by a mixture of six parts distilled or deionized water, two parts alcohol and two parts 10% ammonia.
If you decide to do this, let us know how you get on. Do you have any particular film in mind? I used to use Primetime 640T - no longer available - and EXR 500T.
Stock options shows Fuji F-64D which seems interesting. The other choice would be the Kodak EXR 50D. But the Stock Options website seems to hate me so I'll have to call and see what they have.
Both films are daylight. I figure I'd limit my problems the first time. I wouldn't mind trying the tungsten film with daylight. I think I remember seeing some interesting prints using tungsten film. Of course with my memory who knows what I'm really remembering-)