Panasonic DFD

Raist3d wrote:

brentbrent wrote:

Raist3d wrote:

In GF 9, even when using micro Four Thirds lenses other than ours, we can improve AF performance by utilizing a part of DFD technology.

Interesting. I missed whenever you previously posted this. Thanks for posting it again.

The real bottom line is that DFD or not, I still find Panasonic focuses better (GM5, GX850, GX85) than my OMD EM5 MKII, PenF. OMD EM5 MKII does better than the PenF.

But not only the AF is better, the options are also better. The workflow for pinpoint AF is amazing. That said, the PenF is pretty good with focus peaking in MF.

This raises some interesting issues which might be best illustrated by how Canon EF lenses are handled via Metabones adapters.

Taking the very sharp Canon EF 135mm f2.0 as an example.  For some reason it was one of the hardest EF lenses to give good quick accurate AF when electronically adapted.  It is regarded as one of Canon's sharpest lenses and that may have been part of the problem.

In any case using MF this lens is incredibly sharp.  Once Metabones sorted out how to link the Olympus pdaf routine to the lens it has become equally sharp on the E-M1.  But the "in focus" cdaf image from the GX7 is not quite as sharp as MF or pdaf on the E-M1.  Which is disappointing.

My reasoning runs along the lines that the EF lenses were designed around the use of pdaf focusing methods whereas all M4/3 mount lenses must be designed to first work with cdaf.  I have no technical knowledge of whether a lens understands the difference in its firmware or not but there was little doubt that in the case of the E-M1 the AF performance of Metabones adapters jumped when pdaf was hooked in to replace the Olympus cdaf routine. And so one might guess that there are cdaf and pdaf focus methods and these are probably camera body based and interface with how the lens firmware combines with them.

Therefore does the Panasonic cdaf (DFD-lite) struggle with the relatively old design but very sharp EF 135/2.0 lens?  Later lenses such as the Canon EF 100mm f2.8L Macro have no focus accuracy issues when used on the GX7.

All this comes with the caveat that the 135mm f2.0 has always been a sort of last fontier lens when adapting to other mount systems with AF support.  Now that it does AF easily maybe it simply only needs a little trimming in the accuracy department.