Dark edges issue

Discussion in 'Medium Format' started by tom_kondrat, Jun 10, 2021.

  1. Most of my photographs have darker edges (especially on the sides). I use Mamiya RB67 + 65mm f4 K/L. What could be the problem?

    rb67_372.jpg rb67_381.jpg
     
  2. The problem is in scanning. Light of the scanner lamp bleeds around the negative, and the software turns it into this orangy colour.
    So mask properly when scanning.
     
    tom_kondrat likes this.
  3. You do not say but Is this a Pro SD ? Is your internal mask a genuine 6X8 or has it been modified to 6X8 or maybe just 6X7. Just wondering.
     
  4. Yes, I think you are correct as the negatives look fine. I use Epson V700 with standard film holders. Do you know a way to 'mask properly'?
     
  5. I'm curious to find out the answer. I also use an Epson V700 with its film holders and have not encountered that issue.
     
  6. You have to make sure no light bleeds through the rebate around the actual negative. If the supplied masks do not do the job, adding some stiff black paper might help
     
  7. From negative film presumably?
    Otherwise the edges would be lighter.

    You can get a similar effect if the edges of a filmholder/negative-carrier are reflective or glossy and not chamfered. Any decent carrier should have a 45 degree chamfered edge facing the light-source, and be matt black finished. Otherwise there's a tendency for light to reflect off the underside edges of the carrier and create those darkened edges with negative film/lightened edges with reversal film.

    Maybe a simple additional black paper mask would sort it?
     
  8. Lay the negative flat on the glass see what that does. I never use the holders.
     
    peter_fowler likes this.
  9. I've done that on my Epson V 600 for years now , takes a few extra moments to align and you're off to scanning heaven .
    Possibly a bit exaggerated , but not by much ! Transparencies offer their own challenges (Newtonian something or anothers') .
    I could try and get some anti-newtonain ring glass , but ( I'm Scottish by descent :) ). Peter
     
    laurencecochrane likes this.
  10. My V600 I ran a strip of self adheasive foam strip, I use to make camera light seals down the scanner glass I just slide the negatives edge up against it. The flatbed of the scanner I do not need. Flatbed scanner on my printer. The V600 now negatives only.but not permanent.
     
    Last edited: Jun 13, 2021
  11. Sliding a negative against a foam strip does not cover/mask the rebate of the negative. So while it may work keeping the negative in place, it will not solve the OP's problem.
     
  12. Not too sure if you're familiar with the V600 , but after it does the initial scan you simply use the mouse
    and size the amount of negative you want the final scan to be , hence eliminating the darker section . Peter
     
  13. Yes, similar to this crop line, but the sides still need to come in further to eliminate the dark edges entirely, which means the size would be reducing to nearly 6x6.

    Perhaps fixing the original scanning problem first would leave more scope for cropping for compositional taste, rather than the starting point for every negative being close to 6x6 instead of 6x7.


    Screen shot - crop 2021-06-14 at 2.52.01 PM.png
     
  14. Masking or Laurence's foam should do the trick.

    The effect is due to light entering the edges of the film strip, which act as a light pipe due to internal reflection, allowing the light to bounce and travel a ways into the film before exiting and giving you that boarder. Blocking the light from the edge of the film will minimize this. The rebate plays a much smaller role, but can also produce this effect on dense negatives.

    A simple experiment with the Epson flatbed scanner is to load the negative in the standard holder, and keep the end exposed (ie: don't mask the ends). Scan to the edge of the film, you will see this light pipe effect most times.

    (PS: the mask needs to be on the side of the light source)
     
  15. No but it means I can include or ignore film borders. And I have no edge issues.
     
  16. It's a pretty poor mask/filmholder that allows light to hit the edge of the film side-on!

    But if that's the case, then running a permanent marker pen down the edge of the film might fix the issue.
     
    Last edited: Jun 15, 2021
    peter_fowler likes this.

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