Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: mshea on January 07, 2018, 04:07:39 pm
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Hi All,
Just purchased the A7RIII and haven't even had a chance to play with it yet! But I'm wondering how my M lenses will stack up against the Sony GM series, particularly the GM 24-70. I'm also thinking about constant lens changing vis-a-vis the sensor dust issue.
This will be primarily for prints that are 15 X 25 and larger.
Zeiss Biogon M 25mm f/2.8
Zeiss Biogon M 35mm f/2
Zeiss Planar M 50mm f/2
Leica Elmarit M 90mm
I also own the Leica R Elmarit 19mm, V.2
I'll make do with my Canon 70-200 f/4 and 70-200 f/2.8, V 2 for now.
Any thoughts?
Merrill
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Biogon's don't work well with Sony FF cameras (smearing in the corners) unless the camera is modified to remove the thicker IR/glass that Sony use in front of the sensor, and replace it with something close to the Leica. See Kolari for mods.. The 50 and 90m lenses with more distance to the exit pupil from the sensor should be OK.
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The Leica M glass was made for film, not digital sensors. The digital sensors have a glass cover over them. That, in effect, becomes part of the optical formula. Lenses need to be designed for the specific thickness and characteristics of the cover glass. On my Sony a7rii I can detect the corner issues even with my 75 mm. The 90 mm Macro-Elmar M is the first one I have to not show any corner image degradation. KolariVision makes an Ultra Thin cover glass that helps with many of the M lenes, but even then the Sony cannot match the Leica M9 corner performance with wide angle lenses. There appears to be more to it than just coverglass thickness. I'd guess it's also a function of the sensor micro-lens design.
It's sad, but our M glass less than medium telephoto is just not very compatible with the Sony. Note that although the KolariVision UltraThin coverglass helps tremendously with the 50 mm ZM, it wrecks the image of the new Zeiss Loxia 21mm, which is designed for the thick coverglass. (The Loxia 21 mm is so good, that lens is what caused me to give up on the M wides and coverglass replacement approach.)
Paul
www.PaulRoark.com
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Sorry, I'd forgotten to mention that I'd read about the Kolari modification that I'd need to do. Well, it seems the logical route to go is selling all my M glass. Sigh...
Thanks for the input!
Merrill
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I'd hang onto the 19mm and (if it's the most recent version) the 90mm Elmarit. My little Tele-Elmarit, 1970s design, works great on an A7rii and the newer one is a step up optically from it at f/2.8.
-Dave-