2-sided Film Holders - Help
Okay, what am I doing wrong? Same result with 2 different 2-sided holders, 4 frames, all with the same fogging along the edge. Am I pulling the dark slide too far?
when you pull the darkslide out does it come out smoothly ?
maybe light is leaking in as you pull the darkslide out ... and put it back in ...
I don't think this is a light leak, otherwise the top would be a lot darker.
Please keep in mind, that before exposing you have to pull the dark slide completely out, after exposure you turn the dark slide 180 degrees and put it back in, so you can see that that side of the film holder has been exposed.
This is at the flap end. Bad hinge tape? Light coming in under the flap. It happens.
Another possibility: holder not seated correctly in camera. There are grooves and ridges that have to lign up to make a light trap. One more (actually happened to me) : the width of my Zone VI camera back is wider than my Grafmatic. Regular holders work but the Grafmatic leaks along the long side.
It looks like you have an area of underexposure, not a light leak, at the top of the frame, which would be the bottom of the camera. This might be caused by the bellows impinging on the image area, but there might be some light diffracting around the bellows to give you a partial image.
Then on the right side of the frame it looks like you have a light leak that isn't in the filmholder, because the rebate of the film is clear, so maybe the filmholder isn't seated properly in the back, or the bellows isn't completely attached to the back of the camera, or the bellows has a light leak on that side.
On the left side of the frame there is a light leak that does enter into the rebate of the film. It looks like this film may have been lightstruck on that side before or as it was loaded.
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I think you're right about the bellows impinging. As for the edges, I provided some mis-direction there. The original image was taken using a digicam with the negtive on a lightbox - there's some light-rolloff along the one edge. On the left edge of the photo shown, which is the end of travel for the Speed Graphic shutter (perhaps some more info would have helped you), which was set at 1/30, it hung up slightly so that edge was over-exposed. That problem does not repeat on the thin negatives which were shot at 1/100s. However, the bellows are there in all 4 frames. The lens, for completing the description of equipment, was a cdv/petzval, the testing of which was the purpose of this exercise - you can see the vignette in the corners.
Looks like fogging probably while loading the film into the dark-slides.
on a speed graphic it does not seem usual
for the bellows to be hanging down and obstructing
the film. could there be something inside the camera that
might be doing something similar ?
does the camera have a graflock back, and if so, have you removed
the back and looked inside the back of the camera to see
if there might be something else going on ?
I don't think the film was fogged while loading - The dark area is virtually identical (depth and angle) on all 4 frames. The bellows aren't sagging (although the angle seems to match the shape of the bellows). There's nothing inside the camera. I'm wondering if there's some sort of reflection or strange light behavior going on inside the lens - it's the lens I asked about in this post. It's "press fit" into a black ABS plastic lensboard, threads out, and around 1/2" of lens back into the cavity - having said that, I just looked at the part of the lens inside the body - I wrapped black electrical tape around the first 1/4" or so but the rear edge is reasonably shiny brass. I see more electrical tape and another test in my future. I had tape sealed the hole in the underside of the lens body and saw no light leaks around the aperture, by the way.
could the light be leaking around the lensboard ?
and does this sort of leak happen when you use
a different lens+board?
since film is kind of expensive,
it might be fun+easy to make some quick and dirty
paper negatives to try to pinpoint what might be going on.
you can load paper in the holders and leave them in room/daylight
to see if it is the holders leaking or see if it your loading technique
(load paper in safelight to see what might be going on)
try shooting the paper using aroundish asa 6 or 10 as a starting point
and use both this fun lens with no tape around lensboard and with ..
and then with an actual speed graphic board+regular lens ...
i wish i had some other suggestions ...