Why this discolouration along the edges?

[philipus]

I sometimes see this yellowish discolouration alongside the edges of frames shot with my Hasselblad 203FE. It is mainly visible on higher-contrast shots like the one below which was taken with the 80 Planar FE. I think I can also see it on shots with my 350 Tele-Tessar (I need to test a bit more as I have only recently received that lens). The discolouration shows with both my old A12 magazine and a newer E12 magazine, both of which have new light seals.

On the photo below it is visible along the top and right-hand edges but also to a lesser degree along the left-hand edge.

Any ideas what might cause this?

Thank you in advance
philip

 

[shutterfinger]

Very weak light coming through weak spots in bellows and light seals has a yellow tint. Your sample appears to have slight extra exposure on two sides.
I assume this is noticeable on the negative, if not its the scan.

 

[chriscrawfordphoto]

If its not showing on the film, it may be a scanning issue. Some scanners, like the Nikon 8000 that I use, have problems with flare when you scan the clear edges of the film, and this is exactly the effect it gives!

 

[philipus]

Thank you very much for the quick replies. I will double-check the negatives and post back.

Very weak light coming through weak spots in bellows and light seals has a yellow tint. Your sample appears to have slight extra exposure on two sides.
I assume this is noticeable on the negative, if not its the scan.

If its not showing on the film, it may be a scanning issue. Some scanners, like the Nikon 8000 that I use, have problems with flare when you scan the clear edges of the film, and this is exactly the effect it gives!

 

[polyglot]

Almost certainly this is a scanning issue. It is generally caused by flare within the scanner.

If you cover up the edges of the neg with some card or similar while scanning, it will probably go away. Also, clean your platen.

 

[philipus]

I've done some testing and it's a scanning issue and, thankfully, one which can be fixed. The image above was scanned on my Coolscan 9000 with the Image Mechanics wet mount tray without any masking around (which I normally don't do).

I have now tested with the 869S and Focal Point glass, which evidently doesn't work so well regarding Newton rings. The discolouration is still present.

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Then I tested with the 869GR tray (which deals with Newton rings much better but is a hassle to use with film strips). This tray has a special square mask that one puts on top of the negative. This did a better job to remove the discolouration but there's still some.

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Finally I scanned with the Image Mechanics tray again but now with the square mask on top. The discolouration is still present BUT look at the top, it's only in the middle. This is because the edge of the square mask isn't straight, rather there's a part cut out in the middle. That's what's showing only in the middle along the top edge of the frame.

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So I need to devise a simple mask for use with the Image Mechanics tray, which is the one I prefer to use because there are no Newton rings and I can scan a lot faster than with the 869GR. It probably needs to be a bit wider to ensure no stray light comes in from the sides. Exciting stuff.

Thanks everyone for your help and for putting me on the right track to fix this.

best
Philip