[Leica] Sony A7 RII review with a difference

[John McMaster]

Thanks, ties in with sample variation in the lenses :-(

john

-----Original Message-----
From: LUG [mailto:lug-bounces+john=mcmaster.fr at leica-users.org] On Behalf Of Akhil Lal
Sent: Monday, 2 November 2015 8:11 p.m.
To: Leica Users Group
Subject: [Leica] Sony A7 RII review with a difference

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