klim
member
Reged: 08/24/08
Loc: Matamoras, PA
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A Tale of two Telescopes........
#5434747 - 09/22/12 04:44 PM
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A few months ago there was a thread running about an exchange program that Carl Zambuto was offering for 10" GSO mirrors. He would take in the GSO mirror and for a reduced fee return it with a Zambuto finish. People who took up the offer were very pleased with the results.
I kept wondering though, were people actually making accurate comparisons? After all, these we not side by side comparisons, but rather a comparison of the new Zambuto finish vs. the "memory" of the prior performance of the original mirror.
As it turns out, I have a 10" Orion XT telescope and a 10" Portaball with a Zambuto mirror. I always felt that the Orion had a good mirror and that it held it's own against the Portaball. Of course, that was a couple of years ago while observing Saturn. A few nights ago I decided to do side by side as I was thinking about selling the PB. I could use the money for some home upgrades and just improve the motions on the Orion XT. But first, let me make sure.
Well, this time of the year there are no planets to observe so I started with splitting the double double in Lyra. Both scopes were able to it rather easily, Not much to complain about from the Orion. Next, I tried the ring Nebula M57, Here I noticed that a couple of stars next to the ring were much easier to see withe the PB. Hmmmm........ Then I tried M31 the Andromeda Galaxy. I have 2 24 Panoptics that I use with my Binoviewer so the magnificaton was very similar. Here was an obvious diffrence. After looking through the Orion first and then the PB, it was like switching to HD tv. The contrast was obvious. Many times people use the phrase "telescope A blew away telescope B". Well, this time I think it warranted it. The legendary Zambuto contrast was front and center. After that I started looking at open clusters and again the fainter stars were there in the Pb but not the Orion.
Both scopes were well collimated using Howie Glatter's tools and equilibriated for over 2 hours after sunset. Both were using a 24 Panoptic. Sure, maybe a better seconday was in the PB but I think it was the Zambuto magic that made the differece.
Guess which telescope I'm selling now?
Mark
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Mr. Marbles
professor emeritus
Reged: 04/23/05
Loc: Saratoga Springs, NY
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Re: A Tale of two Telescopes........
[Re: klim]
#5435215 - 09/22/12 10:53 PM
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I thought you were going the other way for a moment.
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SACK
member
Reged: 08/11/11
Loc: Texas, Yahooo!
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Re: A Tale of two Telescopes........
[Re: Mr. Marbles]
#5435244 - 09/22/12 11:12 PM
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I am with Mr. Marbles, my presumptious twist ended with a twist!
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ThreeD
scholastic sledgehammer
Reged: 12/23/08
Loc: Sacramento suburbs
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Re: A Tale of two Telescopes........
[Re: klim]
#5435342 - 09/23/12 12:51 AM
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Quote:
A few nights ago I decided to do side by side as I was thinking about selling the PB. I could use the money for some home upgrades and just improve the motions on the Orion XT.
...
Guess which telescope I'm selling now?
That Orion won't fund nearly as much in the way of home upgrades as the Portaball would...
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Mr. Marbles
professor emeritus
Reged: 04/23/05
Loc: Saratoga Springs, NY
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Re: A Tale of two Telescopes........
[Re: ThreeD]
#5436163 - 09/23/12 01:49 PM
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It's funny you described it as HD. A novice who looked through my 8" Zambuto asked if my "telescope had HD or something?" I don't know to what extent it had to do with the 35mm Panoptic I had in the focuser. He was used to only 1 1/4" eyepieces.
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klim
member
Reged: 08/24/08
Loc: Matamoras, PA
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Re: A Tale of two Telescopes........
[Re: Mr. Marbles]
#5436514 - 09/23/12 04:49 PM
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Yes, the PB would fund more renovation but I would never be happy with the Orion knowing what the PB would do. Don't get me wrong. For the $250 or so that someone spends on it when I put it up, they'll be getting their money's worth.
As far as the HD view, I think that's pretty accurate. Like more lines of resolution enabling more faces in the crowd of sporting events to be seen or seeing the indivdual blades of grass on the field. Almost like a film being taken off the lens.
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apolloadama
member
Reged: 05/17/12
Loc: Sacramento, CA
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Re: A Tale of two Telescopes........
[Re: klim]
#5436531 - 09/23/12 04:57 PM
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It was the best of mirrors.
It was the worst (or just not the best) of mirrors.
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BDS316
Carpal Tunnel
Reged: 09/16/09
Loc: Sol 3
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Re: A Tale of two Telescopes........
[Re: klim]
#5436683 - 09/23/12 06:19 PM
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You may have trouble with the Orion's resale value because the word is now out that Orion does not support used scopes.
Just out of curiosity did you ever swap the mirrors and see what the results would be?
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Mr. Marbles
professor emeritus
Reged: 04/23/05
Loc: Saratoga Springs, NY
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Re: A Tale of two Telescopes........
[Re: BDS316]
#5436810 - 09/23/12 07:24 PM
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I was thinking that could make a difference, but are Portaballs better flocked than the Orions?
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helpwanted
Post Laureate
Reged: 07/04/07
Loc: Phoenix, AZ
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Re: A Tale of two Telescopes........
[Re: Mr. Marbles]
#5436886 - 09/23/12 08:07 PM
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How clean are the mirrors?
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klim
member
Reged: 08/24/08
Loc: Matamoras, PA
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Re: A Tale of two Telescopes........
[Re: helpwanted]
#5437142 - 09/23/12 10:52 PM
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Both mirrors were cleaned just prior to the comparison.
I couldn't swap the mirrors as the zambuto is attached to the mirror mount with some type of silicone adhesive.
The resale value will be priced accordingly. Probably about $250. Includes updated Orion 2 spead focuser 8x50 finder and telrad. I would have killed for this kind of scope for that price as a 15 year old.
No flocking in either scope, just the PB shroud and orion tube. The secondary was deeper in the orion than in the PB.
I will compare star tests, as well as my untrained eye can do, later this week.
Mark
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Jason D
Postmaster
Reged: 10/21/06
Loc: California
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Re: A Tale of two Telescopes........
[Re: klim]
#5437267 - 09/24/12 12:45 AM
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Quote:
As far as the HD view, I think that's pretty accurate. Like more lines of resolution enabling more faces in the crowd of sporting events to be seen or seeing the indivdual blades of grass on the field. Almost like a film being taken off the lens.
Assuming both scopes were collimated and cooled down equally, your description most likely an indication you ended up with a lemon sub-standard mass produced mirror. Though there are bad sub-standard mass produced mirror out there, these tend to be the exception and not the norm.
I had the pleasure to observe through a Zambuto mirror in my XT10 scope. I also spent years of observation with the stock mirror before switching to my Ed Stevens premium mirror. All mirrors were used in the same scope. Based on my experience, my stock mirror has provided me with enjoyable views. I did see an improvement with the premium mirrors in terms of contrast and being able to go to higher magnification but I can never describe the difference as going from regular TV to HD.
My review of Zambuto
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/4780247/page/0/view/collapsed/sb/5/o/all/fpart/1/vc/1
Jason
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Jason D
Postmaster
Reged: 10/21/06
Loc: California
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Re: A Tale of two Telescopes........
[Re: klim]
#5437274 - 09/24/12 12:52 AM
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I will compare star tests, as well as my untrained eye can do, later this week.
I can tell you upfront that your Zambuto will score perfectly with the star test. The star test of my Zambuto loaner mirror was an absolute perfection. The star test of my stock mirror was far from being perfect with clear spherical aberration but that does not mean it was a bad mirror. You have to be careful on how to interpret star test result.
Jason
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GeneT
Ely Kid
Reged: 11/07/08
Loc: South Texas
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Re: A Tale of two Telescopes........
[Re: klim]
#5438491 - 09/24/12 05:24 PM
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I would be interested in the same side by side comparison on either Saturn or Jupiter. Should you make one, please post. My money is on the Zambuto mirror.
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klim
member
Reged: 08/24/08
Loc: Matamoras, PA
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Re: A Tale of two Telescopes........
[Re: GeneT]
#5438875 - 09/24/12 10:15 PM
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I plan on getting up at 5am to check out Jupiter tomorrow morning. I'll let you know.
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Jason D
Postmaster
Reged: 10/21/06
Loc: California
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Re: A Tale of two Telescopes........
[Re: klim]
#5439130 - 09/25/12 03:38 AM
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After looking through the Orion first and then the PB, it was like switching to HD tv
I recall mentioning HD tv in an old post related to this subject. I found the post. It is 4 years old -- almost to the day.
Here is what I said:
Quote:
…based on my upgrade experience, I have more respect for mass produced optics and more appreciation for premium optics.
The difference between the two is NOT the same difference between a regular TV and HDTV -- it is more subtle.
http://www.cloudynights.com/ubbthreads/showthreaded.php/Cat/0/Number/2653956/page/0/view/collapsed/sb/5/o/all/vc/1
Jason
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klim
member
Reged: 08/24/08
Loc: Matamoras, PA
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Re: A Tale of two Telescopes........
[Re: klim]
#5439228 - 09/25/12 07:07 AM
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Heavy fog this morning. Will try again soon.
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klim
member
Reged: 08/24/08
Loc: Matamoras, PA
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Re: A Tale of two Telescopes........
[Re: Jason D]
#5439233 - 09/25/12 07:21 AM
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Prior to HD tv I was very happy with my tube Sony TV. Once I got my HD tv I was able to see a larger picture (more magnification without distortion) and more contrast than my Sony was capable of. The same is true for both mirrors - hence my analogy. Others may use a different analogy and that's ok too.
I still have my Sony, still like it but prefer to watch sporting events on the HDTV, especially tennis matches so I can see the ball getting hit close to the lines and hockey pucks sliding across the ice. When I want to see low contrast faint objects, I'll be going for the PB.
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Jeff Porter
super member
Reged: 09/03/10
Loc: Utah
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Re: A Tale of two Telescopes........
[Re: klim]
#5440876 - 09/25/12 11:48 PM
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Just as a side note myself and another local experienced observer did do a side by side comparison. I had the same mirror that Jason D tested in my XT10i, and we used my friends Orion 10 and XX14i for comparison.
We set up all three of the scopes and set off for a night of observing. Short story of it is that there was a noticeable improvement in the contrast in the image of the Zambuto over the stock Orion and by the end of the night we were actually comparing the 10" Zambuto mirror to the 14" Orion. In this comparison aperture won, but the difference was not as great as we expected.
The result of my experience...I am a believer! The increase in contrast from a reduction in light scatter is real!
Right now I am waiting for my new 17.5" Starstructure TL with Zambuto mirror. I also have an Orion 12" that I will be polishing and refiguring with the help of a local ATMer who has made a number of high quality mirrors.
-Jeff P
Edited by Jeff Porter (09/25/12 11:51 PM)
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