Archived posting to the Leica Users Group, 2016/12/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I have updated my PDF on the astro-photography sensor cover conversion for B&W. See http://www.paulroark.com/BW-Info/KolariVision-Astro-BW.pdf . The update covers my initial views/tests of a thicker (standard thickness) extended red sensitivity cover glass that I had Kolarivision put on my Sony a7rii. This allows the Sony/Zeiss lenses made for that platform to work as expected. To summarize, Kolarivision now has 2 thicknesses of this astro-photography cover glass. One is thinner than usual, but still not as thin as the Leica cover glass. Nonetheless, the thinner cover glass is better for the M lenses than the standard thickness glass. The Sony/Zeiss normal and wide angle lenses did not work well with the thin astro glass. The new Zony lenses assume a specific sensor glass thickness and build that into the overall optical design of the lens, presumably because it allows more compact lenses than simply adopting a retrofocus design. The new astro cover glass which they put together for me matches the Sony cover glass optical thickness, which is very good for Zony lenses, but not as good for M glass as the thinner version. In any case, for dedicated B&W, I personally think the extended red cover glass (think old Tech Pan) is a better approach than a monochrome sensor, at least for me and my landscape types of photography (no so for street work). For me the ability to do multi-color filtering in Photoshop is very important. The color, which needs the white balance at about 2900 is somewhat reminiscent of old Agfachrome. FWIW, Paul www.PaulRoark.com