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-   -   Bent/Warped Negs (http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=2050)

RobReglinski 28th January 2010 02:59 PM

Bent/Warped Negs
 
Hello,

I am quite new at this so sorry if its a dumb question,

I am trying to print from a neg that is warped. I don't mean creased its more like topography (like looking at a hill)

needless to say it is messing with the focusing. Its been under a few heavy books for a few days now and still will not sit flat. Any good ideas?

My enlarger is some weird Russian thing and wont accept anything other than the neg as i did think about squishing it between some glass.

Thanks

Bob 28th January 2010 03:31 PM

Try the negative with the enlarger lens at wide and small apertures as this will effect the depth of focus at the negative stage (can't remember now which way gives more or less depth).

Once plastic film is distorted it is not really possible to flatten it with pressure alone. Heat + pressure might work but the amount of heat needed might be enough to destroy the negative: which many would consider is not an ideal solution to the problem...

I suspect that using some kind of home-made glass carrier will be the only way. Depending on your enlarger's carrier setup, it may be possible to hack a carrier out of some glass, rubber bands and card or thin plywood etc.

I hope someone else will have a better idea than mine!

Good luck, Bob.

Richard Gould 28th January 2010 05:07 PM

Hi Rob and welcome to the forum. What film are you having a problem with, If it foma then the only awnser is at least a part glass carrier due to the curl that foma film seems to have,You can try stoping the enlarger lens down as far as you can,that might just bring it into focus, but for foma glass is best. If it is ilford/kodak/fuji you can try resoaking the film for ten to fifteen minutes in water/wetting agent at 24 degrees, that sometimes works,I have sometimes done that andit has on occossion helped,but is not a complete cure, if you can workout a means of using even a thin piece of glass to hold the neg straight that would be best, Maybe there may be other ideas on the site,Best of luck and let us know how it turns out,Richard

RobReglinski 28th January 2010 06:16 PM

Thanks guys,

Its just FP4, nothing fancy.

I will try a soak and see what happens.

cheers
Rob

Dave miller 28th January 2010 06:40 PM

Quote:

Originally Posted by RobReglinski (Post 24124)
Thanks guys,

Its just FP4, nothing fancy.

I will try a soak and see what happens.

cheers
Rob

It's normal for roll film to be curved across it's width, and to a lesser extent also its length. So don't expect it to be perfectly flat. If it's buckled then it's a problem that only a glazed carrier will overcome.

RobReglinski 28th January 2010 06:44 PM

Hi Dave,

thanks - yes it is, as you say, a buckle and not a symptom of being sealed in a roll.

Ill have a look at bodging a holder to fit the enlarger but it will not be easy.

Thanks

Rob

Mike O'Pray 28th January 2010 08:46 PM

Rob welcome. My experience with FP4 is limited compared to other Ilford films plus some Fuji but I think you may have been very unlucky as I have never experience any real problem with Ilford or Fuji.

I usually leave the film hanging in the drying cabinet overnight and the next day it has only a small curve on it which the glassless negative masks usually flatten. However I have left film hanging with clips at the top and weighted clips at the bottom for 24-36 hours and it was noticeable that the film after this time was even flatter.

As others have said it might be worth a fresh rinse in wetting agent and re-hanging. If you have a drying cabinet do not use the heat assisted fan. At the college where I learned B&W processing the drying cabinets were always on full heat and even Ilford film would curl round a lot in those.

They would eventually uncurl but it could take a long time.

Mike


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