Please advise on the 28-135USM IS combined with the 5D classic.

KnightRT wrote in post #15130969
It is for this lens. The 28-135 begins to blur about a third of the way in from any side. That's more than enough to cover the eyes in most portraits. AF also suffers with the outer points.

i also don't consider 1/3 of the frame to be edge/corner sharpness ...

did you turn of the IS on your tripod shot in the first comparison?

All of those shots were LV-focused, remote release on a two-second delay, MLU, IS off.

I bought the lens when I had only the 5Dc, for the most casual snapshot pictures at birthday parties or walking around with no expectation of serious photography. In those situations it was just fine UNTIL a moment came along for a great shot, at which point lack of contrast and sharpness often left me disappointed in the results. I still use it for that but my expectations are low.

I almost never use it but I took out the 28-135mm one afternoon with the intent of taking the sharpest photo possible. Here's the results with it hooked to a 40D:

Taken at f/11, 1/320" and ISO 400

http://farm4.staticfli​ckr.com …56438868_c5ef06​6926_o.jpg