[Leica] Leica Lenses on Sony /A7s

[r.s.taylor at comcast.net (Richard Taylor)]

I recently tested the new full-frame Sony A7s with a 15mm Voightlander 
Heliar, 28mm Summicron ASPH, 35mm Summicron ASPH, and a 60?s era 50mm 
Summilux and thought you?d be interested in the results.   They are shown in 
the links below.  These are all full-size files and will show the results 
most clearly when viewed at 100%.  These were all taken at the closest 
focusing distance which is the worst case.  The corner smearing is less at 
typical working distances.  The camera has only a 12 MP sensor, but that is 
good enough for most of my uses, and the hi-ISO performance, said to be 
spectacular, was worth exploring. 

I shot these pictures in RAW and processed them in Lightroom 5.5.  The only 
adjustments I made were to equalize exposures in some instances and level 
those that came out at a small angle.  

I think the Leica lenses worked really well.  The smearing in the corners, 
even wide open, may not be serious in practice, unless you put your subject 
in the corners.  The lenses need to be stopped down to at least f5.6 to 
reduce the smearing and f8.0 get rid of it completely.  

The A7s is a *really* nice camera.  Only a little larger than an OM D EM-1, 
it produces good-looking, easy to process files and, as you will see when 
you look at these jpgs, the Hi-ISO performance is astonishing.  The EVF is 
excellent and it?s easy to see the whole frame even with eyeglasses.  With 
Sony autofocus lenses I think it would probably probably be a gem.  If I 
were buying one though, I?d probably go for the A7 because of the higher 
pixel count even though the hi-ISO noise performance is poorer.  

But? focusing was a bear.  Even at the lowest setting, focus peaking was 
sometimes unreliable even wide open.  Stopped down, it was almost impossible 
to use.  I assigned focus magnification to a custom button next to the 
shutter release and, with magnification, focus was almost always spot on 
wide open or slightly stopped down.  Being a disciple of Dr.Ted, though??Oh, 
look at that:  Wow! click"?that procedure is not for me.  A more deliberate 
shooter might find it just fine.  With wides like the 15, zone focus worked 
well. 
 
I am now of the firm opinion that Leica M lenses are only suitable for Leica 
rangefinder bodies.  No matter what fancy electronic focusing system is 
developed in the future there is no way around the fact that you must focus 
wide open to nail focus when viewing through the lens.  

The camera and adapter were rentals and that worked out well.  The 
Voightlander adapter I used has a cool feature.  After releasing a catch, 
it?s possible to screw the adapter outward about a quarter inch to allow 
close focusing with Leica lenses.  I tried it.  It works.  But, I didn?t 
look at any of the images close enough to say anything about the image 
quality close in.  

Here are the results.

15mm Voightlander Heliar:
http://gallery.leica-users.org/v/rtaylor/PICKS/a7s_leica_lenses/15+Voightlander+Heliar.jpg.html

28mm Summicron ASPH:
gallery.leica-users.org/v/rtaylor/PICKS/a7s_leica_lenses/28+Summicron+ASPH.jpg.html

35mm Summicron ASPH:
gallery.leica-users.org/v/rtaylor/PICKS/a7s_leica_lenses/35+Summicron+ASPH.jpg.html

60?s era 50mm Summilux:   
gallery.leica-users.org/v/rtaylor/PICKS/a7s_leica_lenses/50+Summilux+_60_s+era_.jpg.html

? and, two shots with the 15 and 28 at a local playground:
gallery.leica-users.org/v/rtaylor/PICKS/a7s_leica_lenses/Playground.jpg.html

Happy browsing.  Comments always welcome.  

Best, 

Dick