Curving Film- How to avoid?

I'm new to photography and have begun developing 35mm B&W film. The rolls I've developed so far have been curving, bowing across the width of the film. It's not too extreme but I'd rather it be flat. The film also gets a slight twist as it dries.

How can I prevent this? How does one get a nice, flat negative to work with? I'm using a Nikon Coolscan until I can get into a darkroom and the film feeder does not seem to like any sort of a bend in the film.

Thanks in advance for your help.

How are you drying your film?

Focalpoint said:

I'm new to photography and have begun developing 35mm B&W film. The rolls I've developed so far have been curving, bowing across the width of the film. It's not too extreme but I'd rather it be flat. The film also gets a slight twist as it dries.

How can I prevent this? How does one get a nice, flat negative to work with? I'm using a Nikon Coolscan until I can get into a darkroom and the film feeder does not seem to like any sort of a bend in the film.

Thanks in advance for your help.

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I'll let others suggest how to reduce "curl" on your film. But I use a Nikon Coolscan and find that if you lighly flex down on the front end a curled negaitve strip (never less than two nor more than six negs per strip) as you put it into the feeder it will feed okay.

Takes a bit of practice.

Err. you are feeding it with the emulsion side DOWN, right?

Emulsion side down, check.

I'm hanging the film to dry, weighted clip at the bottom.

The problem I seem to be having with the Coolscan is one of two things:

- The film loads but when I try and preview scan it tells me that it's having problems focusing and that I should do it manually, but then that it can't eject the film and I have to take the adapter off and manually turn the rollers to feed out the film. An amusing variant is that program stops responding and crashes.
- The film feeds in a little and then automatically feeds right out.

Could there be a problem with the scanner or the feeder?

In my experience, the acidity of the stop bath determines the curvature of the film. Someone in my old darkroom club didn't dilute the Kodak indicator stop bath before use, so it was super strong. Her negatives rolled up into ridiculously tight little scrolls when she was done. I did some experiments after that which seemed to confirm my theory. Barely acidic or plain water stop bath gave me the least curve to the negatives. I dry vertically with a weight, like you said. The amount of time spent in an acidic stop bath also affects the curl. I'm sure someone out there knows the science behind this, I just know from observation.

Put the negs in sleeves and pile some heavy books over them, they will be pretty flat after a few hours.

film curl

film brand is another factor. I find Fuji Neopan 400 great for flatness and scanning, as well as having excellent image quality for the speed. Iford Fp4 and HP5 are top films OK but seem to have recently got more curl. Under a pile of books is simple/good suggestion.

addendum

chapmank said:

film brand is another factor. I find Fuji Neopan 400 great for flatness and scanning, as well as having excellent image quality for the speed. Iford Fp4 and HP5 are top films OK but seem to have recently got more curl. Under a pile of books is simple/good suggestion.

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I should have added that Efke has been the curliest film I've used. Given that I scan and print a lot, I gave up on it. Too much stress.

After drying for a couple hours hanging, most of my negatives get a slight curl width wise. I then cut them up, put them in their storage sheets, and let them sit under about 2 feet of books overnight. Really flattens them out.

When I dried my 35 mm film in plastic storage sleeves they curled. But since I changed to the paper kind they stopped. Now all film stays completely flat, be it Ilford, Kodak or Efke. Or maybe I changed from acid stop bath to a water stop bath at the same time as I changed to paper sleeves,if the acidity has something to do with it...

/matti

Focalpoint said:

Emulsion side down, check.

I'm hanging the film to dry, weighted clip at the bottom.

The problem I seem to be having with the Coolscan is one of two things:

- The film loads but when I try and preview scan it tells me that it's having problems focusing and that I should do it manually, but then that it can't eject the film and I have to take the adapter off and manually turn the rollers to feed out the film. An amusing variant is that program stops responding and crashes.
- The film feeds in a little and then automatically feeds right out.

Could there be a problem with the scanner or the feeder?

Click to expand...

Focalpoint,

While the Nikon scanners are great machines (I use a 5000D) they have terrible software documentation.

Your scanner is jammed but can only be "cleared" via the software. I did this once and almost tore the darn loading cartridge apart before somehow, serendipitously get it to reset.

As to the OOF etc., what you need to do is find a way to enable the "Calibration" function within the Tool Pallete. Unfortunately, there is no good documentation to tell you how!

Tonight, I'll run through the steps I do and give you a blow-by-blow; but this may not work until you figure out how to "clear" that jam. I think it had to do with turning on the machine w/o the film feeder in it and after you get an error message, putting it in (like I said, it was really weird....).

copake_ham said:

Focalpoint,

While the Nikon scanners are great machines (I use a 5000D) they have terrible software documentation.

Your scanner is jammed but can only be "cleared" via the software. I did this once and almost tore the darn loading cartridge apart before somehow, serendipitously get it to reset.

As to the OOF etc., what you need to do is find a way to enable the "Calibration" function within the Tool Pallete. Unfortunately, there is no good documentation to tell you how!

Tonight, I'll run through the steps I do and give you a blow-by-blow; but this may not work until you figure out how to "clear" that jam. I think it had to do with turning on the machine w/o the film feeder in it and after you get an error message, putting it in (like I said, it was really weird....).

Click to expand...

That's great! I'd be appreciative of anything you can suggest.

It's like the thing knows what I want to scan and goes out of its way to reject it. I've only ever developed 6 rolls of film. The first two were an unmitigated disaster (bad shots and worse developing), but the scanner will accept those strips. Switch to another strip from a new roll and there's no reasoning with it. It's the same brand of film though one is 100 and the other 400.

Again, all and any suggestions are appreciated because the next step for me is to 'clear the jam' via an arc out the window.

Focalpoint said:

Again, all and any suggestions are appreciated because the next step for me is to 'clear the jam' via an arc out the window.

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You could possibly try Vuescan to drive the scanner instead of the Nikon software to see if it has any more luck. You can have both on your machine and you can try Vuescan to see if it works any better before buying it to stop dollar signs appearing all over your images:

Vuescan: http://www.hamrick.com/

First try what I suggested, which is to turn on the scanner and start the Nikon Scan software w/o the feeder inserted.

You should get an error message saying (m/l) "something not found".

Insert the feeder, close the software, then turn the scanner off and back on. Then reload the software and wait. It should sit quiet for a half a minute and then start "winding up".

Then click on "View" in the scanner menu and scroll down to "Tool Palette 1". You should see a window open with a variety of setting options. Scroll all the way down to "Scanner Extras". It will be blank under that heading. Make sure the arrow is pointing down.

Then, try inserting a film strip. The scanner should go into "Preview" mode. When it does, you will see options appear under the "Scanner Extra" section. They will quickly go from black (i.e. "clickable") to grey (cannot be engaged)!

But you will now see a button for "Calibrate". Note that spot because you're going to repeat the "Review" process but want to be able to click on it when it briefly goes to Black! (BTW: your cursor will show as a cross rather than an arrow at this point).

Then, first "eject" the strip. And then position your cursor over the "Calibrate" button. Feed in the strip. As soon as the "Calibrate" button goes to Black - click on it (you only have a second or two to do so!).

If you are successful, the scanner will "wind and grind" as it calibrates the focus and frame settings (the latter are probably out of whack from you're pulling on the strips and manually removing etc.).

Finally, if you are really lucky, when you do the first "unjam" process - it may actually tell you that the thing needs to be re-Calibrated and let you do so without all of the mucking around.

Thereafter, hone your "Calibration" skills by using the "quick draw method" with the cursor.

As I said, Nikon makes great scanners with some of the crappiest software documentation I've ever encountered!

Oh, if you follow the suggestion of trying VueScan, let me know what you think of it. I might want to try it myself!

I normally don't use stop bath (it's not recommended with Diafine, which is my usual developer of choice) and I have the same problem with 135. I find Kodak's T-Max films to be the worst.

George,

I really apreciate your efforts. I'll keep the steps you've outlined for future reference. It doesn't look like my symptoms match up to what you've described. The scanner/software had no issues with being powered on without the feeder. I've been able to feed in and scan some film, but still not others. Ironically, the ones that resist scanning are the ones with the least curl.

I'm going to brave the Nikon tech help area and see if there's anything they can do for me other than suggesting to buy the other adapter (which I'll probably end up doing anyhow).

Thanks again.

Focalpoint said:

George,

I really apreciate your efforts. I'll keep the steps you've outlined for future reference. It doesn't look like my symptoms match up to what you've described. The scanner/software had no issues with being powered on without the feeder. I've been able to feed in and scan some film, but still not others. Ironically, the ones that resist scanning are the ones with the least curl.

I'm going to brave the Nikon tech help area and see if there's anything they can do for me other than suggesting to buy the other adapter (which I'll probably end up doing anyhow).

Thanks again.

Click to expand...

Sorry I couldn't be of greater help. It may be that the sprocket on the feeder is worn and doesn't "catch" the flat strips as well as the curved ones (which would put greater pressure on them perhaps thereby "holding" better??).

I would suggest you run the Calibrate function with any strip you can get to feed. I now run it about once during every roll I scan - particularly if I "cheat" and scan a single frame that is on an otherwise "blank" strip.

Focalpoint said:

I'm hanging the film to dry, weighted clip at the bottom.

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In warm weather, I find putting a weighted clip on the bottom increases the width-wise curl. Experimenting has convinced me that a weighted clip is not needed. If I don't have enough unweighted clips for the bottom of the film strips, I place the weighted clips at the top of the negative strips, which leaves a sufficient number of unweighted clips for the bottom.

Also, when the film is dry, I start cutting it into strips (3 frames for medium format and 6 frames for 35mm), working from the bottom. When lifting the dry film strip in order to cut it, I've sometimes had the top, unweighted, clip lift off the line I use for suspending the film strips. If I put the weighted clip on the top, it prevents the film from lifting off the line while I'm cutting it.