Lens Calibration Help

[dericcainphoto]

I have a 7D and I use a 24-70 2.8L and 70-200 2.8L IS II. Both of the lens seem to focus fine when zoomed in, but when zoomed out, they both miss focus. I do not see how micro adjustment would help this. Has anyone had any luck with any calibration services? I have missed too many shots to not do something about this. Thanks in advance for your help.

 

[Loswr]

Sounds like sending the lenses to Canon Service is the best option. I agree that AFMA won't help in that case (on the 7D, at any rate - this sort of issue is why the 1D X and 5DIII store two AFMA values for zoom lenses).

 

[dericcainphoto]

I pre-ordered a 5D Mark III, so does that mean that I can AFMA on both sides of the zoom when I get it? That would be pretty cool, if so.

 

[Loswr]

I pre-ordered a 5D Mark III, so does that mean that I can AFMA on both sides of the zoom when I get it? That would be pretty cool, if so.

Yes, you can. I have no idea how exactly it uses the two numbers. For example, if you enter -5 at the wide end and +7 at the long end, will it run a gradient of adjustments across the zoom range (progressing from -5 to +7 in small steps as you zoom)? Will it abruptly switch from -5 to +7 adjustment at the midpoint of the zoom range (or some other arbitrary point)? Time will tell...