Exakta VXIIb - light leak or uneven shutter or ...?

[Julio1fer]

I got this camera some time ago but had not really tried it. It came with an Isco 35mm lens that I wanted for my first VXIIb (I guess, this is how you get additional bodies that you don't really need). It is a violation of the laws of economics to find body+lens cheaper than lens alone, but there you go. Life is a mistery.



This second Exakta body had a problem with the lock that holds the back in place; the technician more or less fixed it, and I went to try the camera, with a Tessar lens.

In some frames I got a lighter band at the right side of the picture (darker band in the negative), I am not sure if it is a light leak or uneven exposure. If it it is a leak, it would be on the right side of the picture, i.e. left side of the camera, where the lock is. On the other hand I recall obtaining similar bands in RF cameras with old curtain shutters that needed cleaning and adjustment.

These are two examples of the issue - look at the right-hand side of the picture.





Both these shots were exposed at 1/250. The issue is much less visible on other frames of the same roll; first one following at 1/250, second at 1/125 IIRC. The difference from one frame to the next could indicate that a light leak is more likely than uneven shutter.





What would you bet on? Light leak or uneven shutter speed? I am going to take the camera to the tech anyway, but I would like to hear your expert opinions. Thanks for any comment!

[minoly]

Julio,
I am in no way an expert. I do recall hearing or reading about difficulties with Exakta shutter curtains. Has the recently acquired body got lots of exercise since you received it? It doesn't seem to be a huge or consistent malfunction so maybe moving the parts around a lot might help?
Bill Delehanty

[PFMcFarland]

It would depend on what the whole negative looks like, Julio. Does the light area extend into the sprocket holes? If so, then the light is coming from the back of the film. If not, then it's coming from the front (film gate keeps light from the sprocket holes).

A leak from the back would progress across the image frame-to-frame as the film winds up on the take-up spool, building up the diameter.

If it is always in the same spot, then perhaps your curtains are not completely closing all the time. This could vary with the selected shutter speed.

If it is more intense sometimes, that could be more time between exposures, letting more light past the curtain ends cumulatively.

Take the lens off, open the back, and shine a light from the front while in a darkened room. See if it's getting past the curtain ends.

For door leaks, in a completely dark place (like a changing bag), make sure there is a lens attached to the camera first, then load a short strip of film long enough to go from the canister (just stick one end in the canister, it does not have to be fastened) to the take-up spool, and close up the camera. Then shine the flashlight all around the edges of the door/back. Expose the one frame in the film gate so you know which way is up after you develop the strip. Any leaks from the back will show up quite plainly, and with the image for reference, you should be able to pinpoint the exact place it is occurring.

Or you could just send it back to the technician, and let him figure it out.

PF

[Todd G]

To expand on PF's test just a bit - with the lens off and back open, watch through the shutter as you wind the camera. I have an Exakta VX IIa with a capping problem. As I wind the camera there is one place where the curtains separate just slightly as they're being wound back to the other side of the film gate. This only showed up on some frames, though it was always in about the same place on the negative. But then once I figured out what was happening I realized the frames it didn't show up on were ones I'd wound with the lens cap on.

[Julio1fer]

PF, I forgot it. No light outside the picture frame in the negatives, at all. So it must be something related to the shutter. I do not see curtain separation when winding, nor leaks, even with a loupe in a darkened room, with a pin light in the lens mount.

I suspect a worn curtain cloth, although I see no light through. This could explain why it is stronger in some frames than in others. Or maybe it is the old, unused mechanism as Minoly suggests.

Back to the tech for a shutter rehaul, adjustment, lubrication, whatever it is. I had to do the same with the first Exakta VXIIb, but there the cloth was clearly in bad shape so the decision was easy.

The good part of it, I might get two twin working Exaktas, like a very German pro of the golden ages.

[PFMcFarland]

Hope you do. Two is always better than one.

PF

[GrahamS]

Looks like shutter tapering to me. The closing speed of the second curtain varies across the frame.