Odd exp con on 1DIII

Morning,

I was playing around and thought I'd give a more details look at using exposure compensation but found something odd.

1) Take pic at +3 looks the same as 0
2) Take pic at -3 and darker than 0

Now I expected 2 but I though 1 would look brighter - the subject was a naturally lit corridor so plenty of scope to wash it out if I wanted.

I'll upload the pics later if that helps, I just have to nip out now.

Any suggestions?

Back again - heres the image if that helps.

Oh, it was handheld hence it not being aligned, but as an example I don't think it matters.

IMAGE LINK: http://www.flickr.com/​photos/magsnorton/6822​263327/

Were you shooting in manual for all the shots (I assume you would) and if so that's very strange. When I alter my EV on either the my 7D or 5D2 there's a big difference, especially indoors. The 0 and -3 shots look right, just the +3 hasn't done anything.
I've just shot 3 photos in M and 3 in AV using the same EV and the +3 is way off the scale compared to the 0 both times while the -3 gives a similar pic to yours. Might be an idea to try shooting again just to make sure of your settings.

Hi. If you were not in manual then the safety shift option in the custom functions can "over ride" your settings to get what it thinks is a proper exposure. Do this test in manual mode only and disable safety shift.

Looks like the camera was set to compensate by aperture adjustment, and you were already using full opening at +/- 0. Thus it could close for -3, but not open for +3.
Forget about Safety Shift, it doesn't remove exposure compensation. Automatic lighting optimizer does to some extent, though, but then it wouldn't work with -3 either. So it's probably not that.

Unless I'm loosing it there is no exposure compensation in manual - I think I was shooting in TV mode for those shots.

However I tried again, this time using live view and really watching what the status was doing and saw it moving round, adjusting aperture and ISO and to really bug me I get a light, mid and dark shots.

Hmn, so I figure maybe I was in AV, so I try the same and get correct results again - this is all very strange!

apersson850 wrote in post #13828513
Looks like the camera was set to compensate by aperture adjustment, and you were already using full opening at +/- 0. Thus it could close for -3, but not open for +3.

That would make sense, although the tests I repeated were with the same shot with the same lighting - thanks though its probably right.

I did have a similar things yesterday when out though and it was a bright(ish) day but the images came out really dark - again though probably user error - I've only just got this camera and its much less forgiving than my previous bodies it seems.

Here is the retest result - I still don;t really get it but Andre's idea could well be right, I was just playing and saw the oddness, which I repeated at the time but like a numpty deleted the images before I sync'd up a load of stuff from the day before to by server!

IMAGE LINK: http://www.flickr.com/​photos/magsnorton/6822​853081/

Okay time to crawl away in shame - I had another go to try and repeat the test, this time to my eye as I had originally and got the same original results!!

What I had done was this - I took the original EC 0 shot fine, half held the shutter, released the shutter, turned the dial then took the shot - I then did this again but for some reason kept the shutter half held and amazingly it worked - to further confuse myself I'd set the minimum shutter speed to 60 to ensure I always get a steady shut without introducing camera shake - this also had the same effect a reflects perfectly what Anders suggested.

So between those two I got the same lack of result via two methods!

What an idiot - I have a funny idea that on the 60D it would still do compensation a little while after the half shutter press was released, but used it so infrequently that I could be wrong - either way I'd a bad habit to break!

apersson850 wrote in post #13828513
Looks like the camera was set to compensate by aperture adjustment, and you were already using full opening at +/- 0. Thus it could close for -3, but not open for +3.
Forget about Safety Shift, it doesn't remove exposure compensation. Automatic lighting optimizer does to some extent, though, but then it wouldn't work with -3 either. So it's probably not that.

Safety shift certainly impacted my exposure compensation on the 7D. Not sure about the 1D3 though.