Light leak or something else? Need your help.

[Sanjay Sen]

A few weeks ago I sent out two rolls of Scala and a roll each of Velvia 50 and XP2 Super to the lab and in some of the frames on the processed negatives that came back, there were light patches (please refer to the attached scan). Only the Scala & XP2 rolls had the problem, and in most of the frames in each roll (120 size). All the shots in the Velvia roll came out fine. And as I mentioned, some of the shots in the affected rolls also came out fine. I initially thought that the lab (Duggal in NYC) had messed up, but after thinking about it I am not so sure. Coincidentally, the Scala & XP2 rolls were shot in the same SQ 120 back on a Bronica SQ-A. I purchased this from KEH. The Velvia was shot in a SQ-i back which came with the camera.

My question is: do you think this is a light leak problem with the specific back in question or is it a processing issue? If it is a light leak on the back, why were all the shots not ruined?

Please note that I have only one body and was switching the backs when I wanted to shoot the Velvia.

TIA.

Regards,
Sanjay

PS: My apologies for the poor scan quality - my scanning skills are non-existent.

 

[Dave Parker]

Looks like a dark slide light leak to me.....

 

[Soeren]

Looks like a dark slide light leak to me.....

Yep agree. Is the lighttrap where the darkslide go into that back intact ?
Cheers
Søren

 

[glbeas]

Did the paper wind up tight on the rolls? Some times the drag fingers get sprung and won't keep the roll tight and will give you wierd light marks here and there. You can bend the fingers out to tighten the wind if you see that problem occuring. You also need to check the seals around the latch and hinges to be sure they are intact. A pinhole might not fog the film unless the sun moves into its field of view.

 

[Charles Webb]

This definitely not a processing problem! It is a light leak. But where could be a bit of trouble finding it. I have seen similar exposures on loosley wound roll film handled in bright light. I have seen many roll film users remove the roll in noonday sun and grab the tab of the paper backing while holding the spool with thumb and forefinger and pull to cinch up the roll. Not a good idea!
I am not familiar with Bronica backs, but assume they are similar to Hasselblad. Over the years I have replaced several of these seals, with great success.

Wish I had more to offer, but the streaks did not come from processing!

Charlie..........................