[Leica] More Nerdy stuff.... Sony A7 with Leica lenses.

[Aram Langhans]

Any thoughts as to the color shift maybe due to IR like the M8?  Maybe the 
new cover plate is not as efficient at filtering IR as the original.  Have 
one of the IR cut-off filters from M8 days to check?

Aram

-----Original Message----- 
From: Frank Filippone
Sent: Monday, May 25, 2020 1:18 PM
To: Leica-Users-Group
Subject: [Leica] More Nerdy stuff.... Sony A7 with Leica lenses.

If you own or have contemplated the purchase of a Sony A7 series body to
use with your Leica M lenses, you have heard that Leica WA lenses show
smeared corners due to the closeness of the lens to the sensor.. the
image ray's angle causes problems.

A company, KolariVision, has a modification to the A7 series that
replaces the standard cover plate ( the one that fell OFF my M9) with a
very thin glass cover plate ( I think it is 0.2mm thick. the Leica OEM
plate is approx 2mm thick).  This improves the image quality in the
corners of the frame.... So the question is, if I read all the
literature, is any or all of it true?  Is it just marketing BS?

I went testing ( yes, again).

One of the most awful lenses for this problem used on the Sony A7 bodies
that Leica has made is the 28 Summicron ASPH.  V1.

One of the best lenses on the Sony bodies is the WATE... 16/18/21mm F4
Wide Angle TriElmar  I tried both.  I also tested a 21mm SEM, because I
was asked to.

The cameras were setup identically. The only thing that changed in this
test was the body.( Tripod, same shutter speed, same apertures, same
lens.... )

::::SPOILER ALERT::::::

The Kolari modified body FAR exceeded the IQ of the unmodified body in
the corners...

A7rii vs A7rii Kolari

With 21mm SEM and 28mm Summicron ( notoriously bad on Sony bodies)

At ISO50

At Fwide open, F4 and F8

Distance from camera to center of image was about 15 feet. Tripod of course.

The camera body was place at an angle, allowing for easy access to the
corners ( the horizon line was set corner to corner) ......  Essentially
stressing the lens corner quality as much as possible.....

Focusing was done by x10 focus enlargement in MF mode in the center of
the image......  I did not focus in the corners.... I use a ground glass
kind of focusing, no high tech stuff.  When it LOOKS sharp it IS sharp.

Focus was not done at each F stop... it was done wide open only. Care
was taken to not move the focus ring when changing aperture.

In the center of the frame, there was little to no difference in the
images.  The cameras produced very similar images.... see comment below
about the color shift.....

There was NO condition where the Kolari modified body did not beat, by a
large amount, the corner sharpness of unmodified A7rii.  NONE.  21 SEM,
WATE, 28 Summicron V1.... All the same result.

I also added on the M240/28mm Summicron as a test vehicle against the
Sony body.... The Kolari body BESTED the Leica body.  Not by as much as
the Kolari bested the unmodified body, but it was pretty obvious.

There is no question in my mind, that the Kolari Modified thin glass
cover plate was a BIG improvement to the lenses tested, and I am willing
to bet, it is a big improvement to ALL WA lenses......

Further note:  There is a color difference between the Kolari body and
the Leica or Sony unmodified bodies.  The color shift is expressed as a
purple tint in the Kolari modified body. Especially in the gray areas....

I should have shot a white card and color corrected on that..... maybe
another day.....

I am pretty anal when I do these tests.  I am careful, I look at the
images 1:1 in comparison mode in LR.  The results are correct.

If you want to up your Leica IQ game in the corners.... send a Sony A7
family body and $400 to Kolarivision, and get it done.  It is cheaper
than buying a M-60MP body will be.....

I did not test native lenses on the modified body.  Maybe another day......

Paul Roark ( who found this out for himself several years ago and got me
thinking down this path) ... want to add anything?


PS: If you type in only Kolari to your Google search, I think you get a
porn site.... You will figure that out pretty easily.  It needs to be
www.KolariVision.com

-- 
Frank Filippone BMWRed735i at gmail.com