off center focus

[ScruffyJohn]

was just wondering if this is common issue for the 24-105L
if the 1st image I focused on the the squirrel, notice (to me) the white seeds on the left are more in focus.

The 2nd image, I focused on the lower left of where the snow and bark meet.

[ScruffyJohn]

no comments? hmmm, if I'm being too picky, let me know, I can accept that, like anything mechanical/electronic, one learns to use it within it's limits.... in this case, I would try to focus on the right of the subject a bit ... which then "should" be in focus... need to try that experiment...

[Jim G]

Try searching on here for a focus test - there are a couple of tests out there that can give some indication as to whether a lens may be front- or back-focusing...

[ScruffyJohn]

thanks for the suggestion.. both shots were on a tripod, cable release with IS=off, mirror lock up was not set.
the top image is at 105mm f8
2nd image is at 47mm f8
I focused on the back part of the hole in the ruler (at the 6" mark)
so assuming this isn't worth returning, how would one compensate for this while shooting?

[mike64]

Open your aperature up to f/4, that will reduce the DOF and make it easier to determine if the lens is focusing correctly