Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Reflectors

Pages: 1 | 2 | 3 | 4 | 5 | (show all)
GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Starman1]
      #5610967 - 01/07/13 09:43 PM

Quote:

OMI




I was disappointed in my 18 inch F4.2 mirror. Stellar points and planetary detail never provided the sharp, crisp views that I had hoped for. I have looked through Zambutto mirrors and all of them provided the views I had hoped for in my OMI mirror. If I were buying a new telescope, as said before, I would go with either Zambutto or Lockwood. I have read hundreds of posts on Cloudy Nights and not one person ever posted that they were disappointed with these mirrors. Of course, there are other good mirror makers out there also. Bottom line--I recommend getting the best telescope optics you can afford. They will last a lifetime. You will then know that the object you are viewing is the best it can be (if the optics are collimated, cooled, yada yada yada.)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Deep13
Carpal Tunnel
*****

Reged: 01/25/05

Loc: NE Ohio
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: GeneT]
      #5611305 - 01/08/13 02:02 AM

I only know Zambuto and Orion UK by reputation, both being very good. I have two Discovery scopes and a third one with a Discovery mirror: 8" f/6 (2000), 6" f/5 (2002), and 12.5" f/5 (2005). The first two and I believe the third are all Terry O. mirrors and are very good. Properly cooled with good seeing the 8" and 12.5" give razor sharp planetary images. The 6" is very good too, it's just not a planet scope.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Zamboni
scholastic sledgehammer
*****

Reged: 01/03/05

Loc: Colorado Springs
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: SeattleScott]
      #5612003 - 01/08/13 02:00 PM

Quote:

Comparing Orion UK, Discovery and Zambuto is like comparing BMW, Benz and Bugatti. BMW and Benz are excellent cars that most people will be very happy with, but they simply are not at the same performance (or price) level as a Bugatti. The remaining question is whether Orion UK or Discovery is better. I don't have a Discovery to compare to, and I have to admit my initial reaction is one of hesitation based on both having good reputations. What I do know is that you will get an Orion UK a heck of a lot faster than a Discovery (assuming you are buying a new, custom order). Mine took no more than six weeks including shipping from Europe.




This is a superb analogy. I have a 6 f/8 Discovery mirror (from when Orion's old "DSE" mid-90s dobs were manufactured by Discovery) and comparing it to more current Synta / GSO mirrors is like comparing a Porsche to a Honda.

Nonetheless, a Zambuto is on a whole 'nother level entirely. A Zambuto mirror is the reflector equivalent of an AstroPhysics Fluorite lens. Nigh unmeasurable abberations and the ability to gulp down magnification in a way that seems to defy the laws of physics. On a night of good seeing, the view of Jupiter through an 8" f/9 dob with a Zambuto mirror nearly made me soil myself.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Calypte
Pooh-Bah


Reged: 03/20/07

Loc: Anza, California
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Zamboni]
      #5612058 - 01/08/13 02:23 PM

WRT Discovery: They were pushing out a lot of scopes at one time, and individual mirrors weren't fussed over as (I assume) Zambuto does with one mirror for one customer. Terry O. is a personal friend of mine and near-neighbor (walking distance), so anything I say must be judged in that light. We've often chatted about the mirrors he did for discovery, in light of frequent comments in this forum. He still thinks most of them were pretty good, but he's learned a lot about testing since those days, as has (probably) Carl Zambuto, so I'm not surprised that Carl's mirrors might be better than average production Discovery mirrors. I assembled and tested three Discovery 8-inch f/7s for annual drawings that were held at the Starry Nights Festival (Yucca Valley, CA), and during my few minutes' of testing on Saturn through the clouds, I found them to be very sharp. But I never did a side-by-side with my own Cave 8-inch f/6, let alone a Zambuto.

Post Extras: Print Post   Remind Me!   Notify Moderator  
bilgebay
Post Laureate
*****

Reged: 11/06/08

Loc: TĂĽrkiye - Istanbul and Marmar...
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Calypte]
      #5612128 - 01/08/13 03:04 PM

I have two Zambuto mirrors on order, an 8" and a 12". At least 6 more months to go....

Post Extras: Print Post   Remind Me!   Notify Moderator  
Zamboni
scholastic sledgehammer
*****

Reged: 01/03/05

Loc: Colorado Springs
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: bilgebay]
      #5612157 - 01/08/13 03:21 PM

If anything is worth a long waiting list, it's a Zambuto.

Post Extras: Print Post   Remind Me!   Notify Moderator  
pstarr
Carpal Tunnel
*****

Reged: 09/17/04

Loc: NE Ohio
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Zamboni]
      #5612315 - 01/08/13 04:59 PM

Quote:

If anything is worth a long waiting list, it's a Zambuto.




I lucked into mine. Call it immediate gratification. He had two done at the time I was looking for one in 2005. This was before he sold to the public. Here is a short version of his letter to me after inquiring about a mirror.

Paul,

"This is your lucky day. For one day, and one day only, we will make
available to you a 10" F/6 Zambuto mirror!"

Okay, so it sounded like a commercial (sorry). Without the hype and
hyperbole, its funny you should ask right about now. I have two 10"
F/6 mirrors available for immediate sale. They arrived at the coater
yesterday, and I expect to have them back here week after next. At
that time they will be available for immediate shipment. This is the
first time they have been announced. So contact me privately. I'll try
to hold one for you.


Recently we have had a few spare days here and there to do smaller
mirrors "on the side". Such are the 10"ers currently for sale. We will
continue this as able. We do keep a list of interested parties for 10"
and 12.5" longer focus mirrors.


So Paul, send me a correspondence if you want a mirror.

Carl


Post Extras: Print Post   Remind Me!   Notify Moderator  
george golitzin
Carpal Tunnel
*****

Reged: 02/24/06

Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Calypte]
      #5612475 - 01/08/13 06:35 PM

Quote:

WRT Discovery: They were pushing out a lot of scopes at one time, and individual mirrors weren't fussed over as (I assume) Zambuto does with one mirror for one customer. Terry O. is a personal friend of mine and near-neighbor (walking distance), so anything I say must be judged in that light. We've often chatted about the mirrors he did for discovery, in light of frequent comments in this forum. He still thinks most of them were pretty good, but he's learned a lot about testing since those days, as has (probably) Carl Zambuto, so I'm not surprised that Carl's mirrors might be better than average production Discovery mirrors...




Interesting...I've found some of Terry's mirrors to be really good--an 8-inch f/5 I had was a real gem, providing excellent detail on Mars at 350-400X. A 10 f/5.6 I had out of an old Orion DSE was a dog--badly overcorrected. The 12.5 f/5 I have now looks to be awesome: very smooth surface, with a beautifully balanced diffraction pattern breaking out at equal distances on either side of focus. However, I have to replace an astigmatic secondary before I'll know quite how good it is. From my signature, you'll see I have two Zambutos, both of which are marvelous. I would not sell either, except to finance a larger Zambuto. But I see no reason, at this point, to replace the 12.5 Discovery mirror--it promises to be a killer optic. I guess Terry wasn't always as consistent.

Gene's comment about OMI suggests they have some QC problems too. There was also some negative stuff about OMI at Wolfgang Rohr's site. But my OMI (18 f/4.2) provides pinpoint jewel-like stars and fabulous planetary detail--so again, no need to "upgrade" it.

So the bottom line is what, exactly? When you buy a Zambuto, you know you're going to get something that's as good as possible: if there's any problem in the image, it's the seeing or collimation or thermals or a fault of the structure. Certainly, if you want a reference mirror, he's the way to go.

But once you learn what a good mirror looks like, then you can determine if someone else's work is up to snuff--and I suspect, in the case of this 12.5 I picked up, that that is indeed the case.

geo.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Calypte
Pooh-Bah


Reged: 03/20/07

Loc: Anza, California
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: george golitzin]
      #5612602 - 01/08/13 07:49 PM

Quote:

I guess Terry wasn't always as consistent.



I have no opinion about that. But, again, keep in mind that the Discovery scopes were a production line item. I do know something about Terry's current shop environment, since he is usually polishing/figuring something when I go over there. Most of his work is for contracts -- industry, universities, government, a few for hi-end imaging telescope makers, plus many 6s through 12.5s made as catalogue items for a famous optical supply house. For the general public, he usually won't touch anything smaller than 17.5, since the materials and coating for a small mirror may cost more than a completed new mirror from China, and few people are willing to pay the difference. His shop is spotless and highly organized. He is fanatical about cleanliness. You could eat off the floor. All tasks are widely separated. Testing is done with an interferometer. Some mirror blanks have to be hogged out (depends upon the customer and what they've sent him), and that's done in a separate building using a diamond grinder. He has no carborundum in the shop. I recently saw a picture somewhere of another optician's shop -- don't ask whose, because I really don't remember, but it wasn't anyone discussed in this thread -- and what I saw in the picture looked like a grit-soaked hellhole.


Post Extras: Print Post   Remind Me!   Notify Moderator  
ausastronomerModerator
Carpal Tunnel
*****

Reged: 06/30/03

Loc: Kiama NSW (Australia)
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: GeneT]
      #5612638 - 01/08/13 08:16 PM






I was disappointed in my 18 inch F4.2 OMI mirror.




Hi Gene,

I perceive a big problem with the OMI mirrors to be that they are all 2" thick. This IMO severely impedes their ability to cool and thermally stabilise. Unfortunately OMI only offer mirrors in 2" thickness at the present time.

My 18"/F4.5 OMI mirror (2" thick) is a decent mirror and delivers excellent star points and planetary images, when it cools properly. The problem is that it really struggles to cool under typical Australian temperature conditions. I actually have temperature sensors fitted to the mirror and an external temperature sensor, so I always know what the differential temperature of the mirror is. They very rarely get to within 3 degrees C of each other.

My 14" Zambuto mirror on the other hand is only 1.3" thick and cools beautifully, consequently it delivers to its maximum performance potential a lot more often. I have the same sensors on the 14" scope and it very quickly gets to within 1 deg C to 2 deg C of ambient quite quickly. That's not to say the OMI mirror is the equal of the Zambuto mirror optically, it isn't, but its still a very good mirror restricted only by its thermal properties, not its optical quality.

Cheers


Post Extras: Print Post   Remind Me!   Notify Moderator  
ausastronomerModerator
Carpal Tunnel
*****

Reged: 06/30/03

Loc: Kiama NSW (Australia)
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Bob N]
      #5612644 - 01/08/13 08:25 PM

Quote:

I have owned mirrors from almost all well known mirror makers over the past 30 years -- and Lockwood and Zambuto are the only ones I'll ever buy from again.




I would agree 100% with that comment based on my own experience and the misfortunes of several of my observing friends. You could add Mark Suchtings name to the names of Zambuto and Lockwood, but he is not taking orders at the moment and in any case the current $AUS exchange rate and shipping costs make it cost ineffective to buy a mirror from Australia and ship overseas.

Cheers,


Post Extras: Print Post   Remind Me!   Notify Moderator  
dave brock
professor emeritus


Reged: 06/06/08

Loc: Hamilton, New Zealand
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Calypte]
      #5612862 - 01/08/13 10:53 PM




Quote:

I recently saw a picture somewhere of another optician's shop -- don't ask whose, because I really don't remember, but it wasn't anyone discussed in this thread -- and what I saw in the picture looked like a grit-soaked hellhole.




Quite likely mine (although I'm not a professional). If so, looks can be deceiving.

Dave


Post Extras: Print Post   Remind Me!   Notify Moderator  
Deep13
Carpal Tunnel
*****

Reged: 01/25/05

Loc: NE Ohio
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Zamboni]
      #5612907 - 01/08/13 11:16 PM

Quote:

... and comparing it to more current Synta / GSO mirrors is like comparing a Porsche to a Honda.




Kind of unfair to Honda which are reliably consistent.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Calypte
Pooh-Bah


Reged: 03/20/07

Loc: Anza, California
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: dave brock]
      #5612918 - 01/08/13 11:25 PM

Quote:




Quote:

I recently saw a picture somewhere of another optician's shop -- don't ask whose, because I really don't remember, but it wasn't anyone discussed in this thread -- and what I saw in the picture looked like a grit-soaked hellhole.




Quite likely mine (although I'm not a professional). If so, looks can be deceiving.

Dave



No. It was someone in the U.S., a name I recognized, but I'm not going to offer a guess, which is what it would be at this point.


Post Extras: Print Post   Remind Me!   Notify Moderator  
VĂ­ctor MartĂ­nez
sage


Reged: 02/05/07

Loc: Cádiz - Spain
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Calypte]
      #5613179 - 01/09/13 06:14 AM

I bought my mirror directly to Terry in 2010 and he told me that it was the best of two 16" mirrors that he had maked in his new business and that was really outstanding. I do not know if a few years ago when he maked mirrors in series for Discovery or another company, his quality control would be as comprehensive, but probably today if a mirror is ordered directly to Terry, I dare say that his quality will be exceptional. Mine, when seeing permits and well acclimatised, yields to a level that I think is almost insurmountable.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Deep13]
      #5613911 - 01/09/13 03:15 PM

Quote:

Quote:

... and comparing it to more current Synta / GSO mirrors is like comparing a Porsche to a Honda.




Kind of unfair to Honda which are reliably consistent.




Yeah, i was gonna say this comparo missed the mark pretty badly; if given such a choice, i'd take the Porsche...

Then i'd sell it, buy the Honda, and pocket the diff as a windfall!

But as we say with optics & telescopes, YMMV.


Post Extras: Print Post   Remind Me!   Notify Moderator  
jpb30
scholastic sledgehammer


Reged: 06/18/10

Loc: Uzès ( France)
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: Mike B]
      #5627357 - 01/17/13 02:13 AM

Hello
use for 1 month a mirroir 17 "5 F/D 4 Zerodur Ostahowsky optic, and since I make of the astronomy ( 35 years) it is certainly the best optics through which I observed!!!
In visual in December I was able to observe details of all the satellites jupiter in 900X, it was extraordinary!!! No light diffusion, What proves a roughness of the optical surface very low;Fabulous!!!

Terry possesses a workshop and a excellent interferometric banns test
some picture of mi new scope : http://jp-brahic.chez-alice.fr/t450.htm

jp


Edited by jpb30 (01/17/13 02:17 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
jonstarrysky
professor emeritus


Reged: 01/03/09

Loc: England, U.K.
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: denis0007dl]
      #5627605 - 01/17/13 08:32 AM

There is no simple answer to the question of Zambuto, Discovery or Orion UK. I recently upgraded my 10" f4.7 Orion USA mirror for a custom made ZOC pyrex mirror. I guess I had become wrapped-up in the amazing auora that surrounds CZ and accounts of his mirrors. I really wanted a bit of this action, whatever the explanation. The guy is idolized and has possibly unparalled respect from the astro community. My experience is he is great person to deal with and my ZOC mirror performs very well on the stars. Images are razor sharp. No suprises a ronchi eyepioece gives me deadly stright fringes with the ZOC miror. HOWEVER, I soon realised that my original mass-produced Orion USA mirror was in fact very good its self. I cannot tell the difference with the ZOC on feint stars or nebulae. Believe me I dont want this to be true after the money I spent, but it does seem to be true for me. I suppose that an experienced observer under perfect skies, on a scope with a perfect secondary mirror, will notice that the ZOC mirror is superior, who knows.... So I dont think you can generalise and say brand X is "better" than brand Y, unless if there is proper evidence to support that contention.
Orion UK come from a different fold. They are experienced opticians, hand-making the optics in europe, and have the full phase-shifting zygo interferomety kit, which I gather costs a fortune. They also make optics for professional physics labs and national projects. I have a small amount of direct experience of them. It is likely that they can produce some very good mirrors, I have seen some images taken with equitorally mounted scopes using their mirrors that are astonishing in quality. How Orion UK mirrors compare with ZOC mirrors is unknown, until somebody conducts systematic testing on a large sample of mirrors from both sources.
As somepoint I may consiser selling my 10" f4.7 ZOC or Orion USA mirror. I think the former will fetch rather more money than the latter.

Edited by jonstarrysky (01/17/13 09:01 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
dpwoos
Pooh-Bah
*****

Reged: 10/18/06

Loc: United States
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: jonstarrysky]
      #5627696 - 01/17/13 09:33 AM

It is true that the primary mirror is only one part of the system (which includes the observer), and so upgrading only that one component may or may not make a big difference. It is also true that there is a (decent?) chance of a mass produced mirror being quite good.

I think it is easy to lose sight of the fact that (almost?) all of the info one finds here is based on anecdotal evidence, and that this it is being offered and (possibly) accepted based on very limited understanding of the particulars. I also think that many folks who hang out here want the "best" of this and that, without knowledge of what they have and what they will be getting. It is not possible to "upgrade" anything without this knowledge, unless upgrading simply means spending more and/or getting name recognition. Even if one accepts that "you get what you pay for" (and I don't think that it is always true), that doesn't mean that you get what you need or want.

Edited by dpwoos (01/17/13 09:35 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Thomas Karpf
Carpal Tunnel


Reged: 02/09/09

Loc: Newington, CT
Re: Which mirror better-Zambuto, Discovery or Orion UK new [Re: jonstarrysky]
      #5627713 - 01/17/13 09:49 AM

Quote:

I cannot tell the difference with the ZOC on feint stars or nebulae. Believe me I dont want this to be true after the money I spent, but it does seem to be true for me. I suppose that an experienced observer under perfect skies, on a scope with a perfect secondary mirror, will notice that the ZOC mirror is superior, who knows.... So I dont think you can generalise and say brand X is "better" than brand Y, unless if there is proper evidence to support that contention.




What would you define as 'proper evidence'?

While you certainly can get good mirrors from other vendors (and mirrors from China are definitely getting better), I have NEVER seen ANYONE ANYWHERE say 'Brand X is better than Zambuto', although certainly several other mirror makers are considered AS GOOD AS Zambuto. In addition, there are ZERO bad reports about a mirror from Zambuto (other than two from WAY back where Carl Zambuto refigured mirrors that were not properly annealed).

For me, that's 'proper evidence'.

If you're unhappy with your Zambuto mirror, I'm sure you will have NO problems selling it or trading it for anybody else's mirror.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | (show all)


Extra information
3 registered and 19 anonymous users are browsing this forum.

Moderator:  ausastronomer, Phillip Creed, JayinUT, okieav8r 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 6314

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics