Huygens Optics | Making a monolithic telescope Part 3: Figuring & Testing @HuygensOptics | Uploaded June 2022 | Updated October 2024, 1 hour ago.
Use the following links if you want to skip to the next chapter of the video:
00:00 General intro
01:54 Required level of precision
07:12 Measuring surface shapes with interferometry
10:46 Fringe evaluation with DFTfringe
12:12 Optical Pitch polishing
17:19 Making molds using 3D printing
18:18 Results with variable surface tools
21:06 Primary mirror
22:20 Point Diffraction Interferometry (PDI)
26:48 Visual performance
29:58 NO MORE NAPS (featuring Dr. Fullersheit)

Links mentioned in the video:
Website with the best and most detailed information on telescope optics:
telescope-optics.net/. This is the direct link to the page about the different criteria and how they relate to aberrations: telescope-optics.net/effects1.htm

The 3D-printer used was manufactured by 3Bfab. More information on their products can be found on their website: 3bfab.com (not sponsored content - they did neither ask nor pay me to show their product)

DFTfringe software is programmed by Dale Eason. This is the link to his YouTube channel: youtube.com/channel/UCPj57WFSSLpVqPir7Im-kiw
The software can be downloaded from:
github.com/githubdoe/DFTFringe/releases
This is the link to the interferometry group on DFTfringe that Dale runs:
groups.io/g/Interferometry

The Point Diffraction Interferometer can be purchased for about 50 Euros from Michael Koch at astro-electronic.de
(not sponsored content)

Other videos in this series:
Part 0: Tiny telescope concept video (featuring Rik): youtu.be/HxwhCmO90UQ
Part 1: Optical Design and Aspherics; youtu.be/awOvnubFE8M
Part 2: Machining Glass; youtu.be/A0bysBIj0FA

Special thanks to Dr. Liam Fullersheit for his guest appearance. (;-).