[Leica] Sony A7 RII review with a difference

[alal at nyu.edu (Akhil Lal)]

David Kilpatrick, who reviews hardware for the BJP,  has posted an
interesting review of the A7 RII on his site. An excerpt:

"The E/FE lens-body system is built round a concept of achieving final
accuracy in alignment and focus without needing precision in every
component. The nominal 18mm mount to sensor register doesn?t have to be
perfect (and seems to vary by at least ?0.1mm). All Sony E and FE mount
lenses compensate for variations and use free-floating magnetic focus often
combined with floating OSS ? they don?t have fixed infinity stops. Just as
the bodies don?t have to be all that precise, the lenses themselves don?t
need to be. As long as both work with the sensor to AF perfectly, the
overall system is self-correcting.

You soon find out the limits of E-mount precision when buying adaptors for
older manual lenses or modern Canon EF lenses. I?m sure Zeiss makes due
allowance in the design of manual focus Loxia lenses, and Voigtlander has
specifically allowed the new E-mount range planned for 2016 (10mm, 12mm and
15mm) to focus past infinity because they are aware of the variable
register of the system. I have measured many adaptors and the only safe
decision for the engineer is to fall short of the target register. Some
very expensive adaptors turn out to be 0.3mm thicker than others for the
same mount (I?ve found this in Leica M, Canon FD and Canon EF adaptors).
The lenses being adapted often have a fixed infinity stop and are designed
to hit this precisely. Combine a 0.1mm ?plus thickness? Sony body with a
0.2mm plus adaptor, and your manual wide angle lens won?t focus on infinity.

So, one overall issue is that despite the high cost, the Sony FE/A7 series
range of bodies and lenses lacks the precision engineering of past systems
and it?s designed that way. When you find one side of your pictures always
seems soft with wide-angle, wide zoom or very fast lenses you have
encountered the limitations of Sony precision and quality control."


His view of the Sony A7 line is clearly different to that of other
mainstream reviewers and the full review  is worth reading.      See:
http://www.photoclubalpha.com/


Regards,
Akhil