Camera Mirror Lenses Part 1: Visual and Interferometric Testing

In this video I will discuss the visual and interferometric tests of camera mirror telephoto lenses. Contents: 0:00 intro 1:16 Vivitar f=800mm F:8 mirror lens 4:58 Sigma f=600mm F:8 mirror telephoto 7:34 Soligor f=500mm F:8 mirror lens 8:26 Explaining interferometry in auto-collimation 12:09 Actual interferometry measurement setup 14:58 About Strehl Ratio 17:15 Strehl ratio and aberrations of Vivitar 800mm mirror lens 18:18 Comparison with results of Sigma 600mm mirror lens 20:17 Extro EXTERNAL SOURCE LINKS: DFTfringe software download: https://github.com/githubdoe/DFTFring... Dale Eason DFTfringe group: https://groups.io/g/Interferometry/to... Other videos on DFTfringe software:    • DFTFringe quick start guide version 2 (mea...      • version6      / @daleeason9687      • Making a Mirror with a  Variable Surface S...   User experiences with the Vivitar 800mm mirror telephoto lens: https://www.bhphotovideo.com/c/produc... https://www.amazon.com/Vivitar-800mm-... Syntax-Brillian Bankrupcy and Sakar aquirement: https://seekingalpha.com/article/6660... https://www.cnet.com/tech/tech-indust... https://www.optyczne.pl/1093-nowo%C5%... https://www.sakar.com/ Original Vivitar 800mm Solid Catadioptric: https://www.photo.net/forums/topic/50... https://www.dpreview.com/news/3295932... Vivitar rebranding: https://mikeeckman.com/2016/12/vivita... Star field Foto (by Felix Mittermeier) https://www.pexels.com/photo/galaxy-s... Bokeh bird in garden photo (by kenetik): http://forum.mflenses.com/vivitar-ser... Tommy Cooper photo: https://panorama.nl/artikel/174764/ko... End music: "Floating" performed by the Early Birds (recorded in Eindhoven in 2000). Did I forget to mention you above and are you a copyright owner? let me know and I will set it straight by linking to your original content in these credits.