PDA

View Full Version : AF focus adjustment?


Tordan58
23rd July 2017, 10:40 PM
Has anyone found a need to calibrate the AF? If I understand correctly this takes effect when the camera uses phase detect AF, for instance 4/3 lenses and also m4/3 lenses in situations when camera uses PDAF.

The manual (Menu A2 -> AF Focus Adj.) says "Focal location adjustment for phase-difference AF can be fine tuned within a range of 20 steps."

Does anyone know how much a "step" corresponds to, expressed in mm back- or front focusing? And in what direction to tune, plus or minus?

Thanks
Tord

Ross the fiddler
23rd July 2017, 10:58 PM
I thought I needed it for m4/3 lenses, but there is no label for the lens when saving the data, only focal length, so from that I concluded I was chasing a red herring. You can see a thread I started on that here (http://e-group.uk.net/forum/showthread.php?t=45384). I edited it with a link included. It's well worth reading if determining how the E-M1 Mk II differs from the E-M1 with AF or just how the AF is actually achieved.

*chr

DanC.Licks
24th July 2017, 05:54 AM
Cameras are like fiddles. The position of the sound post that works on one might not work on another. We just have to try and understand what the nature of the fiddle/camera is in order to get the most out of it, and that means a lot of playing around and trial and error, which is exactly what this and the linked thread are all about.

*chr