Removing remjet?

Discussion in 'Color: Film, Paper, and Chemistry' started by Nick Zentena, Jun 22, 2005.

  1. Nick Zentena

    Nick Zentena Member

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    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.
     
  2. Nick Zentena

    Nick Zentena Member

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    BTW I've seen comments that Fuji doesn't use any backing. Is that true?
     
  3. Gerald Koch

    Gerald Koch Member

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    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.
     
  4. Nick Zentena

    Nick Zentena Member

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    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.
     
  5. Helen B

    Helen B Member

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    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.

    Best,
    Helen
     
  6. Nick Zentena

    Nick Zentena Member

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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.
     
  7. matmcdermott

    matmcdermott Member

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    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.
     
  8. Nick Zentena

    Nick Zentena Member

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    I can't get into that website. The forums seem open to only registered users but it won't let you register-)
     
  9. Helen B

    Helen B Member

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    Nick,

    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.

    Best,
    Helen
     
  10. Nick Zentena

    Nick Zentena Member

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    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-)

    Thanks everybody
     
  11. MSchuler

    MSchuler Subscriber

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    I realize that this post is about six years late, but I just tried this formula (on some Kodachrome that I can't bear to throw out) and it worked beautifully.

    Thanks for the formula!
     
  12. hrst

    hrst Member

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    Actually, just sodium bicarbonate works as well! Or carbonate, for that matter. It's the alkalinity.

    The posted recipe is probably optimized for large-term tank usage.
     
  13. Rick A

    Rick A Subscriber

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    I've been using Borax from the supermart, and Dawn dish soap super concentrate after the fix(I process for B&W)with PK-64.
     
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  15. Photo Engineer

    Photo Engineer Subscriber

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    That Dawn is NOT a good idea Rick!

    PE
     
  16. Cinestar-Jo

    Cinestar-Jo Member

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    Hi,
    Just joined the forum so I could say thanks to you guys for keeping the 2006 thread up for so long and especially to Helen for her 'removing remjet after it's dried formula"! Haven't seen it anywhere else and I was having a bit of a remjet disaster after loading my lomo tank badly and having a load of film stick together when I did the borax + bath....lifesaver :smile:. I'm processing remaindered 16mm fujifilm colour as B&W using Caffenol. Looking good so far (but very sepia unlike true B&W caffenol)! After getting some tips on better loading, for fujifilm the borax and sodium sulphate works beautifully as a prewash. Thanks again.
     
  17. carlschulz

    carlschulz Member

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    Are you talking about Isopropyl alcohol or something else? If Isopropyl, what concentration? A local store agreed to process a roll of Kodak Vision 3 in their minilab before they got rid of the machine. A lot of the remjet was removed but there is still quite a bit left. I want to give this a try. Thank you.

    - Carl
     
  18. FujiLove

    FujiLove Member

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    This is a really old thread but anyway, here's what I do to remove the remjet:

    Mix 15g of baking soda in 250ml of warm water (same as your dev temperature) and soak the film in it as the first step. Give it a good shake for three minutes then rinse with warm water with three or four changes, until the water runs clear. Most of the remjet will now be gone and you can start the normal C41 process. After the blix or fix stage, I remove the film from the reel and carefully wipe the back (non emulsion side) with a wet microfibre cloth to remove the last traces of remjet. It comes off fairly easily. Sometimes I also put the whole film in the sink with warm water and gently use the cloth on it submerged. Being careful not to touch the emulsion. Shake/wipe off the water, then dunk the film in the stabiliser as usual.

    Fuji movie film seems to have less remjet than Kodak, so it's a little easier with Eterna etc.
     
  19. carlschulz

    carlschulz Member

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    yeah I know it's old. I copied down a lot of info :smile: I can test a small section (front or end with no pics) with Helen's mixture using the rubbing alcohol. Another site suggested wiping with a photographic cellulose sponge. Again, I can test that on a section with no images. I have 200' of this stuff which is plenty for a little testing.

    I will look into the Fuji movie film. How does the images compare to the Kodak? Does anyone make color reversal movie film anymore? the Kodak is negative but I'm not sure how they get a positive print film.
     
  20. Xmas

    Xmas Member

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    They contact printed on a mask less negative film.
     
  21. Photo Engineer

    Photo Engineer Subscriber

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    Fuji quit production of the negative film as it was not up to the EK standard for the industry. Sorry for all those Fuji lovers out there.

    I am in contact with many rem-jet removers out there. I have yet to have one do it 100% successfully. It fails nearly 100% of the time on typical film lengths .

    In addition, it is NOT made for C41, nor is it made for printing on RA4 materials. The dye hues and contrasts are off!

    PE
     
  22. carlschulz

    carlschulz Member

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    What is on my film right now is a polka dot pattern from the Walgreen's minilab. I knew it would leave some on the film, wasn't expecting that. :smile: As I get into home processing C41, I will try the prewash as part of processing.

    I can't remember if it was this thread or another elsewhere (nor am I going to read through it again to find out) but someone said ECN-2 processing has a machine designed to remove the remjet (which makes sense). It went on to say doing it at home won't be as effective yet some people report getting nearly all of it off. I am curious to know how the guys at CineStill are doing it.
     
  23. Photo Engineer

    Photo Engineer Subscriber

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    Carl, I think the operative word in your post is "nearly". Some rem jet remains in almost every case, and these appear as speckles in the print when the negative is enlarged to a normal image size.

    PE
     
  24. carlschulz

    carlschulz Member

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    Thanks for the advice everyone. When I get into C41 at home I will post an update with my remjet removal results.
     
  25. Xmas

    Xmas Member

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    Did Walgreens detect you had contiminated their machine?
     
  26. carlschulz

    carlschulz Member

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    They knew before hand what I was doing. A month before, they told me they were removing the mini lab. I asked if they'd be willing to make my roll the very last roll. That way it won't hurt other customer's film. They said yes. When I stopped in after the processing they were having trouble getting good scans because of the polka dot pattern of the remjet.

    Last night I finally got my Jobo set up. I am going to start running C41 soon. As I start getting consistent results, I will see about trying the Kodak prewash to remove the remjet. I'd love to know how the CineStill guys get rid of it. I've shot several rolls of that had haven't seen any speckling caused by the remjet. Whatever they are doing, seems to be working.

    Either way, this will be a fun experiment.