I'm going to guess that this is now the oldest factory coated lens in Leica Mount.
coated_sonnar_m9 by zeiss_sonnar, on Flickr
It is a 1936 Carl Zeiss Jena 5cm F1.5 Sonnar from a test batch of coated lenses.
czjsonnar_sn190_5 by zeiss_sonnar, on Flickr
Originally in Contax RF mount, converted to Leica mount using a 60 year old Jupiter-3 mount. (J-3 had bad glass). It is "convertible" now, unscrews from one and back into the other mount.
And the coating is near perfect- glad to report successful life-test for coated optics.
coated_sonnar_m9 by zeiss_sonnar, on Flickr
It is a 1936 Carl Zeiss Jena 5cm F1.5 Sonnar from a test batch of coated lenses.
czjsonnar_sn190_5 by zeiss_sonnar, on Flickr
Originally in Contax RF mount, converted to Leica mount using a 60 year old Jupiter-3 mount. (J-3 had bad glass). It is "convertible" now, unscrews from one and back into the other mount.
And the coating is near perfect- glad to report successful life-test for coated optics.