See previous coverage on the Kolarivision modifications to Sony mirrorless to deliver far superior performance with Leica M lenses. This coverage has been, and will be in Guide to Leica because lens performance is always covered in the native guide. But as before, I’ll likely show some examples elsewhere
Coming soon is a Kolarivision-modified Sony A7R II in which the sensor cover glass has been replaced by glass the same thickness as the Leica M (sensor cover glass still has negative effects even on a a Leica M240, but far less than the thick glass as shipped with Sony mirrorless).
My intent is to compare an unmodified Sony A7R II to a modified modified version, using various wide angle lenses as well as the Leica 50mm f/2 APO-Summicron-M ASPH (which is impaired until at least f/5.6 on a stock Sony, even though it is a 50mm lens). However, a trip to Germany very soon for a special event may delay it by a week or so.
Note well the absurdity being bandied about on internet that the new sensor in the Sony A7R II can somehow undo astigmatism caused by the thick sensor cover glass. Such claims are an exercise in optical ignorance—never mind optical facts. However, the new Sony A7R II sensor is far superior for color shading.
For an example of just how severe the quality losses can be, see the MTF series and through-focus MTF for the world-class Zeiss ZM 35mm f/1.4 Distagon (courtesy of Zeiss)—its world-class performance rendered mediocre by thick sensor cover glass. A jewel into paste glass, just because of the sensor cover glass (until stopped down to f/8 or more).
- Sony A7R: Sensor Glass Thickness, Ray Angle and Image Degradation: Kolarivision Modification
- Sony Kolarivision A7R.MOD: Performance with Leica M lenses
- Ray Angle, Vignetting, Color Shading on a Digital Sensor
- Astigmatism and Lateral Color: Why Performance is Lens + Sensor (aka why do my expensive lenses suck on mirrorless)