[Leica] Leica lenses on Sony A7

[hjwulff at gmail.com (Henning Wulff)]

On 2013-11-09, at 8:56 AM, Paul Roark <roark.paul at gmail.com> wrote:

> Frank Dernie <Frank.Dernie at btinternet.com> wrote:
> 
>> ...
> 
> Two things seem evident to me here, please correct me if I have missed
>> something.
>> 1. The steep angle through the IR filter will always lead to colour shifts
>> in some lenses which will always need to be software corrected.
> 
> 
> Have you ever heard a good explanation for the fact that the color is
> asymmetrical?  That is, if it were just the longer path the light takes
> through the filter at a steep angle, why is one side of the frame different
> than the other?  I think there must be some interaction with the Bayer
> filter.
> 

That's exactljy what it is.
> 
> 
>> 2. These offset microlenses can only be optimum for one exit pupil
>> distance, ...
> 
> 
> I think I've read that the Sony a7R is optimized for more wide angle lenses
> than the plain a7.  The a7 is probably targeted at the zoom lenses and
> 50mm.  The a7r we usually see with the 35mm on it.
> 
Steve Huff seems to unequivocally state that the A7 is better with the wide 
Leica lenses than the A7r. I think the problem here is that the microlenses 
(and the photosites) are smaller, while the distance between the lenses and 
the wells is the same, so the relative scatter is greater.


> I think I also read that the M 240 microlenses are not as "wide angle" as
> the M9.  Some speculation was that Leica was looking for a body for the R
> optics.
> 
> ...
> 
>> I guess the light fall off and colour shift will always be there and will
>> be different for each lens design (and only loosely related to focal
>> length). The extent to which it can be software corrected will probably
>> continue to be developed.
> 
> 
> At least at the present state of technology, I assume this is the case
> also.  I'm hoping the post-processing software can do the job as well as
> the in-camera so that we'll be able to correct optics that are not from the
> body manufacturer.
> 
I'm sure that as more larger manufactures such as Sony and hopefully Nikon 
and eventually even Canon get into this mirrorless FF market, more computer 
processing software will show up along with better sensor design that will 
allow more linear response for both luminance and chroma across the sensor 
for various incident ancles.


> I assume Sony sees its expertise as electronics, not optics.  As such, they
> may actually facilitate an open and flexible software correction method so
> that they can more easily penetrate the existing "fiefdoms" of the long
> established camera manufacturers.  This might be the exact opposite of
> outfits like Canon that want to leverage off their installed base of
> optics.  I obviously want a totally open system that separates the camera
> (digital film) from the optics.  I suspect only Sony has the courage to
> think they can win the "digital film" race in such a market structure.
> 
> 
I think they are the only 'larger' manufacturer that has both the technical 
skill to do this plus no real established system that they feel they have to 
be loyal to. In fact, again and again one of their main failings has been 
that they have been enthusiastic in pursuing the next 'new thing' and 
abandoning promising older systems or ideas, good as they may have been.


> 
>> Some lenses will probably never be all that good on a digital sensor.
>> 
> 
> The worst will probably be my Zeiss 21mm Biogon.  I'll be seeing if, in
> B&W, it makes any difference.  Of the optics I have, the best compromise
> between retrofocus issues and quality is my 24mm Elmar-M f/3.8 ASPH.   When
> I get the Sony body that one will, for sure, be tested on it.  Some early
> beta tester said the Zeiss 18mm ZM looked OK in the minimal testing these
> pre-production guys could do.  I have one of those also, and it's a dog
> compared to the Leica 24.
> 
On my M's, the WATE and the 21/1.4 are the best. I don't have any 24/25's 
except for the Cosina f/4, and it's not in the running. With the profiling 
that LR5 can do for the WATE, almost all of the distortion is taken care of 
and otherwise it works very well.

Henning


> Paul
> www.PaulRoark.com
> 
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Henning Wulff
henningw at archiphoto.com