Black Frame or Extremely Under Exposed

It sounds like your internal lightmeter might be broken.
What is your metering-mode and could you describe your subject?

Good points Nigel,

I assumed that the OP had already tried these things.

Damn!

Last suggestion before you pack it up and send to the 7D doctor is to try a few 'bracketed' (-2 0 +2) shots and see if there is any significant difference between them and if any are acceptable.

If not, I'm afraid its a trip to the menders.

The black frame issue is just that AFAIK, totally black with no image recorded as the shutter doesn't fire/misfires.

nigelbrooks wrote: The black frame issue is just that AFAIK, totally black with no image recorded as the shutter doesn't fire/misfires.

No, not correct. My 5D began producing black frames, then I would also occasionally get a blue-only underexposed frame, or a third type of strangely pixellated variation. Then it corrected itself and I haven't seen a malfunction in over a month. (There are so many different threads going on about this issue that it's hard to keep all of the data visible to everyone.)

Edited by sybersitizen - 08 December 2006 at 18:13

Had a real shock, got a "black frame" only to realise I'd been shooting on manual and hadn't re-set the dial! That'll teach me to check exposure bars!

All's well now.

Rob

Well, Nigel, here's the thing. I was having basically the classic 'black frame' phenomenon for a few weeks. First shot fails, camera locks up, requires power off/on, resulting picture is black. Some time later I began to notice a few blue frames in there as well: First shot fails, camera locks up, requires power off/on but resulting picture is blue. Then still later I also started seeing a few almost-normal images but with weird pixel content: First shot fails, camera locks up, requires power off/on but resulting picture has wrong-colored pixels. But statistically most of the bad frames (about 90%) were still totally black. See what I mean? This was almost certainly one problem manifesting itself three ways, and I think it's very unlikely that it was caused by the shutter. Also, the fact that all three manifestations have completely stopped happening (although I don't know why) indicates that it was indeed a single problem.

I know that some people have reported ONLY black frames, and some of those people have subsequently reported that their problem stopped after a shutter replacement. But others have also reported that the problem was still there after a shutter replacement!

So the hypothesis that I subscribe to at the moment is that the act of replacing the shutter MIGHT sometimes help because the camera has to be partially disassembled and fiddled with; and it could be some other aspect of that fiddling or re-assembly, like cleaning or who-knows-what the technicians do, that actually makes the difference - not the replacement shutter itself.

As I said in another thread on this subject, it's voodoo. ;)

Edited by sybersitizen - 09 December 2006 at 02:47

I checked it in S mode as well and it was still doing the same shots. When I followed the light meter on the camera in M mode, it would still do the same shots as well. I have gotten completely black shots though and the exposure wasn't even close, if anything at all.

When I use the M mode, I have to over expose the shot by 2 and then the shot looks good. When the shot would have worked, this over compensation make for a picture that is too bright.

I have not had the camera just lock up and require a restart to fix it.

So, I guess I don't have the 'Black Frame' then?

Thank for everyone's input.