MIcro Adjustment Question

[the_d]

I've had my 50mm 1.4 for nearly a year now and I've always been disappointed at it's lack of sharpness. Well, I take that back. After getting a 7D last week and adjusting for the lens, I'm getting pretty damned near tack-sharp at 1.4!


Currently, my only other lens is the 28-135 IS (I know, I need a wide-angle). I've read a few sites that suggest adjusting the lens in the widest setting, others say use your most common focal lengh (it's a zoom, I use the whole range). I was wondering what you guys would recommend, or have done with your zoom lenses.


Thanks.

[neuroanatomist]

Generally, perform the AF microadjustment at the longest end of the zoom range. You can then check performance at the wide end, and if a different adjustment is required, you decide if you want to compromise. The logic behind adjusting at the long end is the longer the focal length, the shallower the depth of field. Thus, a wide angle lens is more forgiving of misfocusing than a telephoto. For the same reason, you perform the microadjustment with the lens aperture wide open (shallower DoF, focus is more critical).


I use a LensAlign Pro for my focus testing and AF microadjustment. Even if you don't use the hardware, there are some helpful tutorials and advice about AF microadjustment on the site.

[Johnny Rasmussen]

How much did you adjust? +/- 5 ?