D800 — "gray curtain"

proudgeek

Sorry to start a new D800 thread, but none of the old ones would let me add to them.

Encountered something very strange this past weekend while shooting in Maine. After a few shots under normal conditions and experiencing normal operation, a "translucent gray curtain" (can't think of a better way to describe it, sorry) would descend over my field of view while looking through the viewfinder. What's more, the shutter speed while using in aperture priority would be wildly skewed. For instance, if the prior shot would come in at a shutter speed of 1/1250s, the new shutter speed would be 1/40s. Obviously, totally wrong.

Here's the strange part. I could fix this using a "D" lens (like my 17-35 f/2.8) by moving the aperture ring so that the black flange at the top of the F mount moved all the way over. It was this lens that I experienced the problem most frequently. For my G lenses (like the 70-200) I actually had to remove the lens itself and slide that flange manually, after which it worked fine, until the problem resurfaced again. This occurred using both G and D lenses, although with greater frequency when using my 17-35. I did get the sensor cleaned a few weeks ago, although I've been using the camera for quite a while since then with no issues.

Thoughts?

PB_PM

It could be a mechanical problem with the aperture lever in the camera.

Msmoto

Maine…. sounds almost like an intermittent issue with condensation in some part of the optical path….

Other than this I cannot imagine how an effect as described could occur….

proudgeek

I sort of doubt it was condensation, since I was able to temporarily rectify the issue by sliding that flange along the top of the mount. Also, image quality was fine once I figured out a fix. To me it feels mechanical. The question is, how major a fix is this. Obviously I can't let it go.

heartyfisher

Is that the same "grey" you see when you look through the viewfinder without a battery in the camera?

proudgeek

Is that the same "grey" you see when you look through the viewfinder without a battery in the camera?

No, that was my first thought.