Pentax 6x7 Test Roll Issue

acrobatic_citron · Feb 15, 2022

Picked up a Pentax 6x7 from a Used Camera store so have 30 days to return. I put a test roll of HP5 through and had it developed by a small lab in London.
The first two frames are fine and then some strange marks are apparent on the one long side edge. These marks are not uniform or consistent across the frame. The lab says they are on the negatives which I dont have time to pick up till Monday 21st
Does anyone know what could have caused the marks? Is the camera fine and its probably smudged lens, bad film, bad development?
https://imgur.com/a/AN2muXs
Thanks!

MattKing · Feb 15, 2022

Welcome to Photrio.
Those look like airbells at time of development.

Dan Daniel · Feb 15, 2022

MattKing said:
Welcome to Photrio.
Those look like airbells at time of development.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Yep.

Other than that, nice images and nice tonality.

markbau · Feb 15, 2022

Those marks are nothing to do with the camera but the lab you used needs to gets its act together, that's a bad processing mistake.

Neil Grant · Feb 16, 2022

...camera seems to work, but you should test it quite comprehensively. The shutter on the 6x7 can cap prematurely - though this may only happen at the shortest exposure times. Not sure if they can acquire age-related focus issues, but you might try to test this too.

markbau · Feb 16, 2022

Neil Grant said:
...camera seems to work, but you should test it quite comprehensively. The shutter on the 6x7 can cap prematurely - though this may only happen at the shortest exposure times. Not sure if they can acquire age-related focus issues, but you might try to test this too.

What do you mean by the shutter can "cap prematurely" I'm not familiar with this term. I have a 25 year old Pentax 67, I just had its shutter speeds tested and they were all within spec. The technician said that's normal, even for older 6x7's. Oh, always leave the camera with the film not wound on to the next frame, apparently this can give shutter issues. Meaning, don't wind on until just before taking a photo.

abruzzi · Feb 16, 2022

Shutter capping is when the trailing shutter catches up with the leading shutter because it’s moving too fast (or the trailing shutter is moving to slow.). This will show up as a side of the image not being exposed at all.

the easiest way to test is to take a few shots at the highest shutter speed the camer has (this only an issue with focal plane shutter like on the P67 and most 35mm SLRs.) it happens at the highest speeds because the slit between the leading and trailing shutter is smallest. Since the shutter curtain on the P67 moves from right to left, it will happen on the left side of the image, but since the image is exposed upside down, if you view the image upright it will be unexposed on the right side.

Sirius Glass · Feb 16, 2022

I recommend that when one shoots 120 film that they store the film in film case like this

for 5 or 10 rolls of time to prevent light piping if the roll is not tightly rolled. Nothing to do with your problem which as others have said appear to be air bells.

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Pentax 6x7 Test Roll Issue

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