Film Curl

[nworth]

I just finished processing 10 rolls of Kodak 400UC, a film I like very much. The results were good, except for one thing - curl. The film curled along its short dimension enough so that I can't scan it and it is almost impossible to control in an enlarger film holder. This happens from time to time, and it may be weather dependent, although the curl seems to last. I put a couple of rolls into the usual polypropylene sleeves and put them in a Seal mounting press (heat turned off) for a while. It seems to help some. A pair of mount boards and some books would no doubt do as well.

But why should I be bothered with this? It occurred to me that APS film, which uses a different base, stays very flat. There may be other issues, but why couldn't film manufacturers make all still films on a non-curling base? Since film has become a niche market, the buyers would probably be more than willing to pay a few cents more for it.

 

[LAMitchell]

Maco/Rollei R3 film uses a poly base. No curl, as flat as a pancake. Its a niche market film and TBH all film will eventually go that way. in the mean time try a drying cabinet to make sure it is completely dry.

 

[Dave Parker]

Awe come on guys, learning how to deal with film curl is one of the rights of passage to becoming a photographer!



Dave

 

[Robert Brummitt]

I use to use a hair dryer to remove curl from E-6 film. It made it easier to mount into the plastic or paper mounts.

 

[Nige]

lol @ Dave.

I bought some J&C Classic 120 and it curls lengthwise something chronic. I do my contact sheets out of the sleeve under a sheet of glass (yes I reckon there's a difference but that's another arguement!) and it's very hard to get them aligned unde the glass. Annoys the hell out of me.

 

[Robert Brummitt]

If you dry film while in reels they will have a curl. For my 35mm and 120 film, I hang them straight while drying with weights clipped on bottom. That takes the curl out of the lenth of the film.

 

[Neal]

Dear nworth,

It's doubtful that the film base is the cause of the curl. It's much more likely that the drying conditions caused the emulsion side to shrink a bit (I may be wrong but I'll bet the concave side is the emulsion side). I would like to find out how the minilab machines do it as I never have a problem with the amount of curl from Qualex.

Neal Wydra

 

[Kino]

Your Qualex probably does it like the MP machines we have; counter current drybox drying. Hot, dry air enters with freshly processed film, follows along with drying film, and exits when film exits; the humidity liberated from the film travels with the film and obtains an equalibrium in temp and humidity before exiting the drybox and taking up on a flange.

Dry film shouldn't be totally dry; the film should be about 50% RH at room temp. Any more dry than that, and sproing...

 

[Neal]

Thanks Kino.

 

[Changeling1]

I would get that with Ilford B/W films. I cut the dried film in strips of six or seven frames and stacked them on top of each other. I then rolled the strips in the opposite direction of the curl and secured it with a small studio clamp. Let it sit like that for 48 hours or so and see if doesn't get an improved attitude!

 

[downfader]

I was getting severe curl on all my films. I still do now and again. I know this guy on another forum who swears by leaving his film hanging in a cool, dry atmosphere, and as dust free as possible (obviously ) but its the length of time he hangs it for: 24 hours.

I most often get curl when I hang it in the down stair bathroom. It dries too quickly, even with weighted clips. When I hang it in the up stairs bathroom, which is cooler I never seem to have that problem.

I need to get a spanner and adjust the radiator in the downstairs, I think.