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GSO vs Edmund Optics mirror

ATM Beginner Dob
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#1 hydrox

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Posted 14 September 2021 - 03:46 PM

Hi all, I'm an ATM newbie and want to make my first telescope. I'm looking at GSO 12" f/5 on agenaastro and a 317.5mm f/6 Protected Aluminum on Edmond Optics www.edmundoptics.com/f/precision-parabolic-mirrors/11895 and the prices are very far apart.

 

Is the difference just because of labor cost? What spec should I pay attention to to tell if one is better than the other?

 

Also from the wavelength I assume Protected Aluminum is the appropriate coating for telescope making?

 

Thanks,



#2 Jim45157

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Posted 14 September 2021 - 04:23 PM

i would go with the edmund optics for sure those short mirrors from china that i had was not very well corrected  just my 2cents 



#3 MeridianStarGazer

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Posted 14 September 2021 - 04:31 PM

Aliexpress has very cheap secondaries, way less than agenaastro. But their parabolic primaries cost more.

Edmunds is definitely ultra premium. So is Thorab.

#4 ngc7319_20

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Posted 14 September 2021 - 04:31 PM

The Edmund mirror is probably made in the USA to higher standards, hence higher price.

 

Yes either Protected Aluminum or Enhanced Aluminum.

 

There are other mirror sources.  Maybe 6 years ago I had excellent experiences with Orion Optics in the UK.  Superb mirror delivered in 30 days with interferogram and enhanced coatings.  Price about $1600 USD + shipping + some import duties.

https://www.orionopt...0-f5-3-primary/

 

Also

https://opticwavelab...m/parabolic.php

 

Zambuto is probably the highest quality, but wait times are around a year...

https://zambutomirro...om/mirrors.html

 

The key question is probably delivery times...

 

A question might be "what are your interests?"  Do you want to see nebula at medium powers?  Or do you have a keen interest in observing the planets at very high powers?

Probably any of these mirrors would be OK at medium powers, but the premium mirrors will really shine at very high powers on planets.


Edited by ngc7319_20, 14 September 2021 - 04:39 PM.

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#5 hydrox

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Posted 14 September 2021 - 08:03 PM

Thanks all for the mirror source recommendation. Right now I mostly want planet viewing. I do see many of the vendors are sold out / back ordered :/ I guess patience is key during this time



#6 Bill Jensen

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Posted 14 September 2021 - 08:37 PM

You may be able to find a good used mirror, as part of a used dob. There are some good older mirrors as part of dobs listed  on CN classifieds right now, depending on whether they are close enough to your location. Discovery had a lot of Terry O mirrors in them and one is listed in the classifieds, , the Night Sky 12.5 inch dob listed has a Pegasus with a very good test report. Otherwise, you could probably get a decent deal on a used "commercial" dob and remove the mirror and any other components that would work for your ATM build. It may be cheaper, and available "now". 


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#7 Pinbout

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Posted 14 September 2021 - 08:44 PM

if your into planetary then I get this

 

https://www.cloudyni...-optics-mirror/


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#8 MeridianStarGazer

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Posted 15 September 2021 - 09:21 AM

Nova Optical systems may be our only source of mirrors right now.

#9 hydrox

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Posted 15 September 2021 - 03:28 PM

You may be able to find a good used mirror, as part of a used dob. There are some good older mirrors as part of dobs listed  on CN classifieds right now, depending on whether they are close enough to your location. Discovery had a lot of Terry O mirrors in them and one is listed in the classifieds, , the Night Sky 12.5 inch dob listed has a Pegasus with a very good test report. Otherwise, you could probably get a decent deal on a used "commercial" dob and remove the mirror and any other components that would work for your ATM build. It may be cheaper, and available "now". 

Thank you. That's a good idea. I never thought of that. Let me go through the classifieds. When I went through them my mind only focuses on mirror. D'oh.

 

if your into planetary then I get this

 

https://www.cloudyni...-optics-mirror/

Thanks Pinbout. It looks beautiful. Unfortunately I'm on the other coast

 

Nova Optical systems may be our only source of mirrors right now.

Are they still around? When I go to www.nova-optical.com, the website doesn't work.

 

Thinking about it some more. For a complete newbie like me, perhaps start with a cheap used mirror is better for learning and practice. Don't want to unintentionally damage a high quality one
 



#10 MeridianStarGazer

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Posted 15 September 2021 - 10:37 PM

...

Are they [nova optical systems] still around? When I go to www.nova-optical.com, the website doesn't work.

...


Steve's site was working very recently, but seems to be down now. A duckduckgo search does not return his site at all. He posts here all the time. Did he retire, or did his site get hacked?

You should PM Steve Dodds and ask.

Edited by MeridianStarGazer, 16 September 2021 - 12:34 PM.



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