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EdgeHD 9.25 Zygo interferometric data

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#1 rlillard

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Posted 20 October 2020 - 12:10 PM

I have googled for this and not found anything.  Does know if this data is available somewhere ?



#2 Eddgie

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Posted 20 October 2020 - 02:24 PM

http://fidgor.ru/Obs...2/test_327.html

 

http://fidgor.ru/Obs...2/test_408.html

 

http://fidgor.ru/Obs...2/test_401.html

 

http://fidgor.ru/Obs...2/test_365.html

 

http://fidgor.ru/Obs...3/test_521.html

 

http://r2.astro-fore...estron-c-9dot25

 

http://r2.astro-fore...-9dot25-im-test

 

http://r2.astro-fore...rich-gebuerstet

 

http://r2.astro-fore...ttliches-geraet

 

In addition to these, there are a few C9.25s on this site, but they do not give wavefront. Still, you can compare the quality on them and you can see that the quality varies a great deal.  There is one that looks quite excellent in the Ronchi double pass and in the star test, but there are a couple that are rather low in quality.  No numbers though so you just have to compare to see I think.

 

http://teleskop-spez...-teleskope.html

 

Not sure what your goal is, but I have seen at least a dozen tests for C9.25s and my own conclusion is that the quality is quite variable with a bad one now and then, and an excellent one now and then, and a lot in between. 



#3 rlillard

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Posted 21 October 2020 - 12:14 PM

Thank you for the links.  Even this small sample is all over the place.

 

I believe these are not the EdgeHD models though.  I asked because I recently bought a previously owned EdgeHD and am curious as to what to expect.



#4 Eddgie

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Posted 21 October 2020 - 03:48 PM

I have seen several tests for the EdgeHD models (though not the C9.25) and they have been varied.   To the best of my knowledge the mirrors are the same mirrors and come off of the same assembly line, so I would not expect them to be any better in serial production.



#5 Astrojedi

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Posted 21 October 2020 - 11:59 PM

http://fidgor.ru/Obs...2/test_327.html

 

http://fidgor.ru/Obs...2/test_408.html

 

http://fidgor.ru/Obs...2/test_401.html

 

http://fidgor.ru/Obs...2/test_365.html

 

http://fidgor.ru/Obs...3/test_521.html

 

http://r2.astro-fore...estron-c-9dot25

 

http://r2.astro-fore...-9dot25-im-test

 

http://r2.astro-fore...rich-gebuerstet

 

http://r2.astro-fore...ttliches-geraet

 

In addition to these, there are a few C9.25s on this site, but they do not give wavefront. Still, you can compare the quality on them and you can see that the quality varies a great deal.  There is one that looks quite excellent in the Ronchi double pass and in the star test, but there are a couple that are rather low in quality.  No numbers though so you just have to compare to see I think.

 

http://teleskop-spez...-teleskope.html

 

Not sure what your goal is, but I have seen at least a dozen tests for C9.25s and my own conclusion is that the quality is quite variable with a bad one now and then, and an excellent one now and then, and a lot in between. 

 

This post is completely unrelated to the op's question.

 

These tests have been questioned on these forums many times and found not to be a credible sample set. I think you should posting these again and again.

 

These are old scopes with significant selection bias (i.e. the owner wants them tested as they feel it has an issue). The optical quality is significantly better and much more consistent these days especially for the EdgeHDs.


Edited by Astrojedi, 21 October 2020 - 11:59 PM.

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#6 rlillard

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Posted 22 October 2020 - 04:12 PM

Thanks to AstroJedi for the context.



#7 JMP

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Posted 24 October 2020 - 01:39 PM

There are two reports on C9.25 HD posted at Airylab free test reports. Quite good actually.

#8 rlillard

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Posted 26 October 2020 - 02:32 PM

Thank you.  Much better than standard SCTs but not as good as I hoped.  To be fair, I'm new enough at this to have unreasonable expectations.




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