Motivated by these threads https://www.ultravio...technical-data/ and https://www.ultravio...-uv-at-the-zoo/ , I decided to run my mirror lenses through a quick test - and I have more of them than I remembered   I own the following lenses, all in M42-mount: MC 3M-5CA 500mm, f/8 MC 3M-6A 500mm, f/6.3 Soligor 500mm, f/8, /11, /16 (via a aperture weel, but I restricted myself to f/8 [Edit]this one is T-mount with EF-adapter[/Edit]) MC MTO 11CA 1000mm f/10 I took some shots in UV, VIS and IR,