garycoleman wrote in post #10902132
I tried a Canon 10-22mm and auto focusing seems a lot more inconsistent towards the wide end (10mm). I can see the the focus scale vary a lot everytime I press the shutter button halfway. As I zoom towards the longer end, the auto focus seems more consistent.
I assume the focus is inconsistent at wide angles because the details are smaller which makes it harder to focus using through the view finder phase focus? Is using Live View contrast focus and zooming in 10x the only way to focus properly using wide angles?
A very wide angle lens has quite a lot of dof, so the image will be relatively insensitive to focus errors. Thus the camera AF system may not settle on exactly the same AF position as still be "in focus". Do your shots at 10mm frequently seem out of focus?
Secondly, the camera may be picking up different objects to focus on from shot to shot as objects of differing distances (and contrasts) will be closer together in a WA scene. If you are using all AF points, differing AF points may be selected from shot to shot. Are you using only the central AF point only on an area where it cannot easily choose a different subject?
Mike K
