20D: Strange Camera Behaviour. Has Yours Done This?

Settings:

EOS 20D with 17-40mm f/4 L. Camera set to Manual and f/8, using various shutter speeds. Lens set to manual focus. Camera focus lock beep turned off. Tripod and remote shutter release used.

Strangeness:

I was out last night, doing some night photography and my camera started behaving strangely!

I had the camera and lens set as described above and was out taking photographs. After taking a few photos without any strange goings-on, I was metering via the remote shutter release (lens on manual focus) and all of a sudden the bottom focus point started flashing and beeping, as if it was confirming an AF lock. Both AF and the beep were turned off. I checked the lens AF/MF switch (which was on MF), and also the lens distance scale, to see if it was trying to autofocus (it wasn't), then carried on photographing.

Nothing strange happened for a little while, then it started doing it again. I checked the AF/MF switch again, switching to AF, then back to MF and it was still doing it - beeping when metering and lighting up the bottom focus point. I double-checked that it wasn't trying to autofocus by looking at the distance scale on the lens (no movement), then I switched to AF and metered again to see if it would autofocus as expected (it did, with no beep, as per the camera settings). I went back to MF and carried on photographing without the problem happening again.

When I got back home and started inspecting my photographs I found that the aperture values are all over the place and I didn't touch the selector wheel for the aperture value. And before anyone suggests that I must have, I can assure you that I didn't.

The camera was set to f/8. All the photos that I took before the camera started behaving strangely were at f/8, as per the settings I made. The photos that I took after it played up the first time were all f/6.3, then all the ones I took after it started playing up the second time were f/7.1. I didn't notice that it had moved from f/8 because I had set it to that, hadn't touched the adjuster wheel and wasn't expecting it to change itself.

I later went on to set my camera to f/16 for a few photographs, but after one photograph I did notice that the camera had moved the setting to f/18, so I set it back to f/16 and carried on with no further problems.

I don't know if it is related, but a while ago I had and Error 99 whilst using my 70-200mm f/4 L and I later found that the camera had changed the aperture value after I had switched the camera off, then on again. The aperture value change coincided with the Error 99. Just to reiterate, I didn't change the aperture value manually, accidentally or otherwise on either of these occasions.

Has anyone else had this occurrence? Is it an indication of a problem, or just one of those stupid things that cameras do, but shouldn't? I think I have got away with it this time, but the unexpected aperture change could have ruined all my photographs. Any comments or observations gratefully received.

Thanks

Mike

That is strange..

I've had the beeping of a focus point in manual though - I figured it's trying to confirm that I've focused on something :P

Other than that... it seems very odd

Thanks for your reply aLFaDaRK.

I did wonder if it may be something like that, but I have my beep turned off! When I set my lens to AF to try autofocus, it worked okay - including not beeping, as per the camera settings!

Mike

Mike-DT6 wrote in post #4778773
Thanks for your reply aLFaDaRK.

I did wonder if it may be something like that, but I have my beep turned off! When I set my lens to AF to try autofocus, it worked okay - including not beeping, as per the camera settings!

Mike

Heh

As with every single problem I ever have with anything, it is entirely possible - in fact probable - that this problem is completely unheard of. If fact I expect that I am the only person in the history of the modern world to have experienced this particular camera stupidity!

Mike

I've never had this.

Mike, what was the temperature outside at the time? Not sure whether cold would or could be a factor.

Hello Kevin

It wasn't really that cold. I have been out in much worse. I'm not sure about the actual temperature, but it was nowhere near cold enough for a frost. Just cold enough to wear gloves - putting it in scientific terms!

Mike

Were you by chance using a battery grip while all of this was happening?

No, nothing like that. I haven't got a battery grip!

Mike

You should inspect the contacts at the lens mount of the camera.
Any bending, misalignment, weak cushion, need for cleaning?

Okay, thanks, I'll have a look.

Mike

Cameras are getting to be more and more like computers, it may have been worth shutting it down and taking the batteries out, effectively re-booting it. But it's only a guess MIke, and a bit too late now anyway!

I can't say I've heard of this one before, certainly sounds a bit weird.

cheers
Bill

I had something like this happening just before one of my lenses broke. Since it's happening with more than one lens, check the lens contacts in the camera. Make sure they are clean and one of them is not stuck in on its spring mount.

Even in manual focus, the camera will confirm focus with a blinking AF point in the viewfinder, if it is seeing something in focus.

Seems normal, though I haven't turned the beep off on mine so that it still beeped is strange. But the rest seems normal.

Mike
It's lucky you didn't apply your "motto" to this situation.