IS problem on 24-105?
Having finally become the proud owner of a 5D and 24-105 lens at the weekend, I'm now a bit concerned that the IS on the lens isn't working. If any of you can suggest a definitive test that I can apply before I go back to the shop, that'd be great.
I've tried looking through the viewfinder (with the shutter half pressed), but can't see any difference between having the IS on or off. This is compared to a shop demonstration of IS (with a different lens / body combination 20D and 17-85, I think) that I had a few months back where the difference was very obvious.
I've also shot a few comparison images and looked at them (zoomed in) on the back of the camera (not the computer screen yet, though), and again can't see any diffence at the same shutter speed. The speed range I tried covered 1/100 to 1/4, at various focal legths.
Helpful suggestions greatly appreciated.