Problem getting sharp images on the wide end when subject far away

I have been having trouble getting sharp images when the subject (i.e. people) is at least 5 meters away and when I am shooting at the wide end (i.e. 24mm). I tried this with 2 lenses: canon 17-40 and tamron 24-70, and on 2 bodies: 5d3 and 6d. I played around with the micro adjustments on the 'W' slider, but have not been successful. The tele end of both lenses are fine and produces acceptably sharp images, but the wide end is the problem. Does anyone have this issue and if so how do you fix it?

It would help if you posted up a sample image that shows the problem clearly. The 17-40 is not the sharpest of Canon's lenses but on the wide end the DOF is usually so great that it's hard to imagine that you could notice if something is OOF.

yes, photos and settings would help.

Here are some photos: 6d, 17-40mm

100% crop

The white side (19mm) is over 5 meters away and it looks blurry.

The yellow sign (26mm) is within 3 meters and it looks reasonably sharp.

Nothing appears to be in focus in the first one. That sort of suggests camera movement, which is hard to believe at 1/320 & 19mm. I'll shoot some with my 6D/17-40 this weekend. I am usually at f/8-11 with that lens.

Weird question but are you shooting One Shot, or on Servo?

These are 100% crops and they're underexposed.

Do you get the same results with the 5D3?

Have you tried focusing with live view?

How anal are you about having sharp images...is it worth going thru the hassle of micro-focusing your glass and learning proper technique?

I may be wrong (my vision ain't what it used to be) but on the first shot it looks to me as if the sharper focus is farther back -- it looks like the passenger door handle is in focus.

The context is that "Automatic Focus" doesn't always behave as we'd like. Without getting into a complicated discussion, I'd say learn to work with your AF, using a good, clear viewfinder view and also your Live View to get that focus right where you want to, and nail it!!!