This past weekend something happened with this lens mounted on a 800e. I was shooting horse trials and cross country jumps.This 28-300 was used the first day because of it's light weight and wonderful range. Well during the day and it was a long one, the shutter started to heat up and began to vignette at longer ranges. I had to shoot high speed burst to catch the action and thought that was the issue in fact there were times the shutter would hang and not close till the camera was turned off and on again.
Next day shot with the 70-200 2.8 no problem. So what do you folks think? Was the 28-300 just not sturdy enough for rapid shooting on a hot day all day? Maybe that is why it's not classified a pro lens?
Any thoughts? Oh the fellow I was working with wanted jpeg files at f 5-5.6 @ iso 200-400 so that is what he got.
No photos available he downloaded the files and cleared the cards.