19 februarie 2017

Canon EF 85mm f/1.2L II USM - AF Fine Tune optimal aperture

Focus shift can be a very problematic and annoying issue on fast aperture prime lenses due to Spherical Aberration.

If your camera has the ability to fine tune autofocus (AF Microadjustment), set your lens to its optimal aperture that you will be primarily using, then fine tune the autofocus. 

In this video the "optimized aperture" is f/1.4. Using maximum aperture (f/1.2) results in slightly back focus after this type of calibration.

I used:
- DataColor Spyder LensCal
- Canon EF 85mm f/1.2L II USM Lens
- Canon 5D Mark III

2 comentarii:

Roby spunea...

I use this lens with Canon 6d. Shot at f/1.4, center focusing point AF only, but most of pictures are out of focus. I'm aware that this lens is difficult to focus, but the results are extremely disappointing.

How do you manage to focus 85mm 1.2 II properly?

Pandects dpVUE spunea...

At f1.4 the DOF is crazy thin. You will need to either move focus point on the eyes and shoot without recomposing or fine tune with MF.