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...  
   • version6  
   / @daleeason9687  
   • Making a Mirror with a  Variable Surf...  

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.