Canon 28-70L front focus at tele end

I have been reading forums and other boards and read about the experiences of front focus/back with this lens at the telephoto end (70). I sent in my lens for calibration and it came back basically the same. My 70-200 2.8 IS is fine and so is my 17-40 , so is there something inherent in this lens that leads to focus issues at the telephoto end?? I have not done any formal tests but indoors it is considerably softer at 70 and very sharp at 28mm, my tamron 28-75 also exhibited no issues at the telephoto end.

I am using this lens on a canon 5d. It is very sharp even at 2.8 28mm. 28-50 range seems better. Can anyone comment on their experiences with this lens?

Did You send the body and lens for calibration at the same time?

No I did not , i would imagine if it were a body issue it would occur with the other lenses also. I cannot part with my body for almost 3 weeks now ,I have got a shoot coming up. Besides the body is out of warranty.

Will Thompson said:

Did You send the body and lens for calibration at the same time?

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The adjustments are quite elaborate and there are different settings in the camera for different lenses as well as across the board settings.

Depending on the problem it is possible for a body setting problem to only show up with only a certain lens or lens model.

I will consider that route, but first try it on a different body and see how it behaves.

the body is out of warranty would each lens cost seperate ? along with body?