Hi,

I afraid (happy?) my experience with the 5D is almost a mirror image of yours. Of all the lenses I have for my 5D only the 85F1.8 shows any sign of vignetting wide open and even then it is only visible with uniformly lit areas.

17-35F2.8L, 28-70F2.8L, 70-200F2.8L, 300F2.8L, 85F1.8, 100F2.8Macro

All of these lenses are at least 10 years old but lay unused for 5 years or more due to me doing an OU degree but I'm wondering if QC is now a significant problem with Canon products in general. I'm sure there must be pressure to get as much product out the door to meet demand as they possibly can. That pressure may not have been there during the age of film when Canon were not so dominant and hence the problem may not be so apparent with older higher end lenses.

It really is a crying shame about the 24-105. If it didn't vignette so much it would be an almost ideal lens.

Regards...
Steve