Thank you Ed! I always find your ATM videos to be very informative. I was pleased to see your comments concerning the Bath IF at the end as that is more likely within the realm of your 'typical' ATM. Would have also like to have seen a shot of the Draper Machine doing its thing and the difference in the motion after 'fixing' the lap. Again, thanks for sharing. :)
i found it's REALY HARD to find the final "ok" for a focal ratio between my favorites eyepieces aviable or Not and the "best"exit pupils . Almost an obsession, and after many weeks of reflection i think i have found f/D ~7.62~~~😅 .this is my first pyrex 201mm~. realy nice vidéo.
I had this question and I found the answer using logic. Follow my steps and say if I am fooling you(and in that case, myself): - Astigmatism comes from asymmetrical abrasion of the mirror. - Abrasion might come from uneven distribution of abrasives or uneven loading or uneven tool total path length for different sectors of the mirror surface - When you spin the table and the mirror on it distribution of abrasives and tool path lengths distribute evenly - But if the mirror is on the bottom it is being pressed to the support surface which might have some asymmetrical curvature - In that case the mirror is bending and thus the loading distribution becomes uneven - If you spin(or change positions frequently) the mirror relatively to the table, you evenize loading of different mirror segments
Thank you Ed! I always find your ATM videos to be very informative. I was pleased to see your comments concerning the Bath IF at the end as that is more likely within the realm of your 'typical' ATM. Would have also like to have seen a shot of the Draper Machine doing its thing and the difference in the motion after 'fixing' the lap. Again, thanks for sharing. :)
Darn impressive video----Great mirror!
i found it's REALY HARD to find the final "ok" for a focal ratio between my favorites eyepieces aviable or Not and the "best"exit pupils . Almost an obsession, and after many weeks of reflection i think i have found f/D ~7.62~~~😅 .this is my first pyrex 201mm~. realy nice vidéo.
The BEST and final method is evaluating with te star test this mirror.
Here's a shot without the field lens: opticaleds.com/optical-testing-and-mirror-refiguring-2/
nice
Where is ZYGO interferometer??? I'm see Ronchi grating and Bath interferometer.
tnx "grind parabola mirror"
What are the specs for your field lens? Even in optical handbooks, that is rarely defined.
I have a couple of field lenses, they're COTS Newport lenses. Usually +500 mm.
What book did you mention at 4:00 please?
Texereau
Does anyone know where the interferometer yahoo group moved to??
im just curious how rotating the mirror makes any difference when it is spinning in circles anyway.
I had this question and I found the answer using logic. Follow my steps and say if I am fooling you(and in that case, myself):
- Astigmatism comes from asymmetrical abrasion of the mirror.
- Abrasion might come from uneven distribution of abrasives or uneven loading or uneven tool total path length for different sectors of the mirror surface
- When you spin the table and the mirror on it distribution of abrasives and tool path lengths distribute evenly
- But if the mirror is on the bottom it is being pressed to the support surface which might have some asymmetrical curvature
- In that case the mirror is bending and thus the loading distribution becomes uneven
- If you spin(or change positions frequently) the mirror relatively to the table, you evenize loading of different mirror segments
Ed, What type of Zygo interferometer did you use?
I use a Zygo GH
🇹🇷🇹🇷🇹🇷🇹🇷💯💯💯💯👍👍👍👍
What is an "innerferometer"?
1959Berre It is used with the oudderferometer.
If you have to ask, you should buy your telescope instead of making one.