I've noticed a couple of times now that when handheld, my 500IS will sometimes give really odd results. The whole image is essentially blurred, even with a high shutter speed and bracing against something. I have never seen it happen on a tripod, so that leads me to thinking that perhaps the IS can do tripod mode, but isn't working properly for the "active" mode?

It does not seem like a simple focus issue, as essentially nothing is in focus. I have also had my focus adjusted already due to it frontfocusing quite badly when I got it.

I admit that I have thought it could be the Mk3, but not all were taken in Servo, and I have only had one other frame (with the 24-70) show this sort of result, out of about 5000 clicks on the body. These were not taken in a burst either.

Here are some samples:

www.gschneiderphoto.com/500blur/

The good folder has pics taken from a tripod. Does the sharpness seem up to par?

Have you tried hand holding with IS turned off? I used to hand hold my 500 all the time with IS on and off. Usually if my shutter speed was high I would not bother using it. Another thing is if you are shooting with IS and take the photo before the lens has time to stabilize you will get weird results which could be what is happening. Give the lens a second to stabilize before pressing the shutter and see what happens.

I have that too ~ don't have the 500L but am undecided if it is the MKIII or the IS not settling, or I shooting too quickly.

The bad photos look like misfocussing to me - it doesnt look like the IS is syncing as there is no 'directional' blur. Looks like its seriously front focussing again.

The pics in the good folder look ok to me but not astounding. My mates 500L looks far sharper!

*Yup, the "bad" images are Holga-like in quality. With those high shutter speeds you should not be having any motion blur difference between IS on and IS off mode. However, I am not sure how steady you are really holding the lens.....a high frequency hand tremour could theoretically still generate some motion blur.

*The tripod images are obviously better but still marginal IMO. The shutter speed of 1/400sec is generally too low for jittery birds. However, I can not see any evidence of misfocus.

I think at this time it would be best to do some stationary test target (3-D) shooting with IS turned OFF and then ON, as opposed to photographing birds which tend to add another dimension to the problem.

Thanks all. I am quite certain that it's not me. I was bracing the lens off my knee while sitting, and it was quite steady, not to mention the 1/2000+ shutter speeds.

I agree with the sharpness of even the tripod images. I would have expected better and my 100-400 is just as sharp I dare say.

I've gone through a stupid amount of hassle with it (3 trips to Canon, 1 to a 3rd party repair shop), and it's not working correctly all the time. Am going to see if I can somehow get a replacement lens from Canon as it is months past the return time. Don't know how far I'm going to get, but this is clearly a lemon.

maybe send in the camera too.

I had very similar results with my 500 and mark III when shooting out of the car.

I have a thread in DP Review about it. I hope this link will get you there.

http://forums.dpreview.com/forums/read.asp?forum=1032&message=27514660

It's not heat shimmer or vibration, for all those pics I was well away from the car/house.

I am pretty sure I let the IS settle for a half sec before taking the pics as well.

Added some RAW samples to the "good" folder, to remove any sharpening inconsistencies. How do the RAWs look? These are about as good as I've gotten.

Bumping this in case anyone interested missed my last update.