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Perennial subject, Hubble Optics.

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#1 lukenukem

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Posted 22 January 2013 - 04:35 PM

Hi all,

After an obscene amount of foul weather here in southern England, I decided to join the namesake forum.

I have currently been trying to get the latest low down on the activities of Hubble Optics. For the most part searches have brought me here time and again, but nothing I can gather, of recent. I have also noticed a pattern. Apparently superb mirrors versus dreadful ones and a lot of mediocre inbetween. People also appear to fall into camps. The 'ask-holes' ( hands up, that probably includes me ) who seek the justification to buy these inordinately cheap mirrors,those who just see the worry words "Chinese and E bay" and others who seek near impossible perfection.

Please forgive me if I have not noticed a more recent and relevant post on the subject. I don't want to come across as the lazy newcomer seeking other to do his research, but my own searching has taken me so far and I would enjoy the fresh perspective you clever bunch can give me.

thanks :)

#2 michalh

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Posted 22 January 2013 - 09:00 PM

Perennial indeed. the latest, longest recent thread is here, I believe. Forgive me as I don't know the forum shorthand:

http://www.cloudynig...5194593/page...

I'll see if I can find a better way to post a link.

#3 michalh

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Posted 22 January 2013 - 09:35 PM

I guess that link method works okay. There are 7 pages, so go to the end to get the most recent posts.

#4 Pinbout

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Posted 22 January 2013 - 09:38 PM

I figured it was cheap enough that I could still refigure it if it was bad enough. And i tested mine on an autocollimator and the edge is turned but the majority of the mirror is jail bar straight, meaning a really good figure.

#5 starman345

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Posted 23 January 2013 - 05:55 AM

I guess that link method works okay. There are 7 pages, so go to the end to get the most recent posts.

Take a look here for info on how to post a link. :)

#6 lukenukem

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Posted 24 January 2013 - 08:34 AM

Thanks for the link, and apologies for the oversight.

#7 starman345

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Posted 24 January 2013 - 10:14 AM

I just noticed you are new here, where are my manners? Welcome to Cloudy Nights :grin:

#8 ManojK

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Posted 15 February 2013 - 01:58 AM

Hi all, sorry to resurrect, but I have been thinking about acquiring either a 14" or 16" sandwich mirror from HO. Went through many threads here including the one started by starman345 (but it didn't answer my question) and I have noticed that all the reports of bad mirrors seem to be from a while ago. Has this company improved the QC on their mirrors now? Or is it still a gamble? Their website also claims a strehl of .95+ now instead of 0.997 or whatever before.

#9 PaulEK

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Posted 15 February 2013 - 01:26 PM

ManojK:

I'd like to know that myself, as I'm thinking about the 14 inch, too. I am one who bought one of these (a 10 inch) several years ago, and it turned out to be a dog: about 1/3 to 1/2 wave. Still, I had it re-figured to better than 1/10th and the total cost was far less than buying a premium mirror. My question has been about the issue of re-figuring a sandwich mirror. Is it doable? Has anyone had experience with this?

#10 starman345

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Posted 15 February 2013 - 01:42 PM

I haven't said much about my 14" Hubble Optics mirror yet because I'm working through getting my build smoothed out. I had to add some stiffness to my focuser board..collimation was all over the place, also, I"ve only had the scope outside three times so far. Each time has been better than the last as I make adjustments, and finally I"m getting those stars to focus to points, although not yet perfectly. I have some better collimation tools on order, I think that may help dialing in the scope. Also, I have coma everywhere except in the center of the view and I find that annoying but I guess that isn't the fault of the mirror but rather the focal ratio of f4.48. A Paracorr hopefully will fix that.
I plan to update my Hubble Optics build thread once I get all the kinks ironed out, I don't like to post an opinion of the mirror until I"ve done everything possible to allow it to perform its best.
Are you thinking of building a scope with an HO optic?
I just checked the Hubble Optics store on Ebay, they are still quoting the +.98 strehl numbers there.

#11 starman345

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Posted 15 February 2013 - 01:44 PM

You and I were posting at the same time Paul, I too would like to know if anyone has had their HO mirror re-figured.

#12 careysub

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Posted 15 February 2013 - 01:55 PM

...My question has been about the issue of re-figuring a sandwich mirror. Is it doable? Has anyone had experience with this?


It would be interesting to ask this question of the opticians know to do refiguring (Swayze, Zambuto, OWL, etc,. etc.) to see if they have done sandwich refiguring and what their views on the matter are.

#13 polaraligned

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Posted 15 February 2013 - 02:12 PM

Before you waste your time refiguring, you may want to check the anneal of the glass...You get what you pay for (for the most part) in this world.

#14 PaulEK

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Posted 15 February 2013 - 10:17 PM

Well, the last Hubble mirror I got (not a sandwich) was annealed properly enough to take re-figuring just fine. But I realize this is a risk.






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