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Recommendations for a faster 75-100 mm refractor

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#1 Pintail

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Posted 20 February 2013 - 10:25 AM

If you had approximately $1500-$2000 to work with and were looking to upgrade to a faster refractor in the 75-100mm range (like something around f/6 or better), what would you suggest?

I also have an ES 127, so the ED80 replacement would be for wider field AP work. It would also be nice to transfer the Moonlite focuser/stepper motor/controller that currently sits on the ED80 over to the new scope, if possible.

Thanks in advance.

#2 Jon Isaacs

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Posted 20 February 2013 - 10:27 AM

If you had approximately $1500-$2000 to work with and were looking to upgrade to a faster refractor in the 75-100mm range (like something around f/6 or better), what would you suggest?

I also have an ES 127, so the ED80 replacement would be for wider field work. It would also be nice to transfer the Moonlite focuser/stepper motor/controller that currently sits on the ED80 over to the new scope, if possible.

Thanks in advance.


NP-101s are sometimes available used for around $2000... F/5.4 with the 4 element flat field design.

Jon

#3 johnnyha

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Posted 20 February 2013 - 12:14 PM

+1 - assuming you can stretch your search up to 101mm. :grin:

#4 Daud

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Posted 20 February 2013 - 01:53 PM

How trusted is the collimation on used one ?

#5 johnnyha

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Posted 20 February 2013 - 02:06 PM

They hold collimation well, the idea that they lose collimation is somewhat overblown. They can be user-collimated but it's difficult to be precise. TV will do it for something like $275 so that could be figured into the price if it is an issue.

#6 Scott Beith

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Posted 20 February 2013 - 07:05 PM

TMB 92SS f/5.5 with a 3" Feathertouch focuser.

link

#7 Starhawk

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Posted 21 February 2013 - 10:08 AM

I'd really like to have a chance to play with one of the 92mm TMB scopes. I'm really curious about color and field flatness with them. It would appear to be an ultimate mobile scope.

-Rich

#8 rflinn68

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Posted 21 February 2013 - 10:14 AM

TMB 92SS f/5.5 with a 3" Feathertouch focuser.

link


I've been looking at these for some time now. I noticed Astronomics took the TMB 92 Light off the website. Are they not making it anymore? :(

#9 Jon Isaacs

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Posted 21 February 2013 - 10:20 AM

I'd really like to have a chance to play with one of the 92mm TMB scopes. I'm really curious about color and field flatness with them. It would appear to be an ultimate mobile scope.

-Rich


Rich:

It shouldn't have any more field curvature than any other 480mm-500mm focal length doublet or triplet. Which is to say, it is probably noticeable but hopefully not bothersome.

Jon

#10 Thomas Karpf

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Posted 21 February 2013 - 10:21 AM

Perhaps the StellarVue SB-80S?

#11 Pintail

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Posted 21 February 2013 - 11:05 AM

I'd really like to have a chance to play with one of the 92mm TMB scopes. I'm really curious about color and field flatness with them. It would appear to be an ultimate mobile scope.

-Rich


Me too. That's pretty much what prompted my question, as the 92L looks to have gone the way of the dinosaur. The 92SS still looks interesting, but I was hoping to avoid the costs of switching platforms from the Moonlite to the FT.

Thanks everyone for the suggestions.

#12 bouffetout

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Posted 21 February 2013 - 12:32 PM

StellarVue SV80ST-25SV...80mm ,triplet apo ,480mm FL ,f/6
Made in U.S.A. And tested by Vic himself ( the boss )
Hand assemble one at the time ,with awesome customer service !
No need to change the focuser...The new 25SV are very good for astrophotography !
Maxx

#13 Starhawk

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Posted 21 February 2013 - 02:22 PM

Is there a flattener for the TMB92SS? And anyone know if the FT3" focuser has the ability to end in AP style 2.7" thread for compatibility?

If yes on these, now we're talking.

-Rich

#14 KevH

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Posted 21 February 2013 - 02:46 PM

StellarVue SV80ST-25SV...80mm ,triplet apo ,480mm FL ,f/6
Made in U.S.A. And tested by Vic himself ( the boss )
Maxx


Made in USA? Looks like a kunming united 80mm with the SV focuser to me. Perhaps I'm wrong though.

#15 Starhawk

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Posted 21 February 2013 - 07:44 PM

None of the SV scopes have been made in the USA. The SV site is carefully worded to leave an ambiguous impression. And a search of the US patent office shows not one patent for Vic or his company, I'm afraid.

Draw your own conclusions about what this means.

-Rich

#16 EdZ

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Posted 21 February 2013 - 07:49 PM

Best scope under 100mm I've ever used TMB SS 80mm

#17 bouffetout

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Posted 21 February 2013 - 08:19 PM

None of the SV scopes have been made in the USA. The SV site is carefully worded to leave an ambiguous impression. And a search of the US patent office shows not one patent for Vic or his company, I'm afraid.

Draw your own conclusions about what this means.


-Rich

All the pieces are made in china and who knows where else...
but they are all assembled in the U.S.A.
If the pieces are not to StellarVue standards ,they will be sent back. They assemble only The best pieces and matching optics !

#18 Starhawk

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Posted 21 February 2013 - 08:25 PM

Uh, huh.

I make stuff for a living. You can't inspect quality into it.

-Rich

#19 jrcrilly

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Posted 21 February 2013 - 08:26 PM

but they are all assembled in the U.S.A.


Most models are assembled in the U.S.A., but not all. There's no telling what percentage of total units produced falls into either category.

#20 bouffetout

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Posted 21 February 2013 - 10:30 PM

I will not argue any longer with a guy who owns zillions of telescope...You are right ,I'm wrong...who cares ???

#21 microstar

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Posted 22 February 2013 - 12:47 AM

This is quoted from Vic Maris on the Stellarvue Yahoo forum:

"...many people labor under the misconception that the source determines the quality. This is not the case as I have mentioned before. Your question gives me the opportunity to further illuminate.

We write a contract for lens polishing that includes our requirements which are extensive and detailed. We test each objective we receive to ensure they meet our standard. When they do not, they are returned before we pay for them. This method, which we have used for 14 years, means that the lenses we use are as good as if we made them here.

Many suppliers overseas offer commercial lenses that are made to their standard (often just about 1/4 wave) and these are not sufficient for a high end apo triplet. But that is not to say that a particular manufacturer cannot make a truly high end objective. If a company wants to produce a telescope that looks the same as a Stellarvue, it can be done at less than 1/2 the cost by simply using a commercial lens made to a lower standard. No one here would be happy with that telescope."

Pretty much echoes other posts on other threads, that Far East manufacturers can make high-quality lenses and scopes, but they can't necessarily do it any cheaper than North American manufacturers (I believe this sentiment was attributed also to Roland at Astro-Physics, but i could be confusing postings). I think it's fair to say that you pay for quality. You may hit the jackpot and get a really good mass-produced scope, or you may get a mediocre one. Stellarvue is saying they will ensure you get the former. Does it matter what the source is? How much was machined or manufactured here vs there? You're paying for quality and in today's globalized manufacturing system that quality could come from anywhere. I bought a SVR90T based upon Stellarvue's assurances and reputation, and Mr. Rohr's classification of this scope as a "super-apo" because of its color correction. The cynics may say I got duped - I don't know if you're right, but you would think if a company was selling Kunming United mass-produced scopes at a high markup it wouldn't be able to pull the wool over its customer's eyes for long. I prefer to take Vic at his word and trust Stellarvue to deliver a high-quality scope, which is what I think I got with my SVR90T.
...Keith

#22 Jon Isaacs

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Posted 22 February 2013 - 08:51 AM

If a company wants to produce a telescope that looks the same as a Stellarvue, it can be done at less than 1/2 the cost by simply using a commercial lens made to a lower standard....

Pretty much echoes other posts on other threads, that Far East manufacturers can make high-quality lenses and scopes, but they can't necessarily do it any cheaper than North American manufacturers (I believe this sentiment was attributed also to Roland at Astro-Physics, but i could be confusing postings).



I don't have good feelings about statements like this one...

The implication here is that the other manufacturers who use the same suppliers do not have the same standards as StellarVue. This is a backhanded slap at those other vendors without actually providing any real information. I find this a distasteful attempt to differentiate SV's product line from the competitors. Hawk your own wares, don't deride others...

Back when SV main products was the AT-1010, the SV page hyped the AT-1010 and derided other vendors scopes with their "color laden Chinese Optics." Of course there came a time when Hardin Optical who handled the GSO scopes in the US began marketing the same scope under their brand, GSO scopes are made in China/Taiwan. Hawk your own wares, don't deride others.

My interpretation of Roland's statement that you could have the highest quality made in China but it would cost you the same as it would cost in the US, he wasn't talking about Long Perng and Kunming... and he was talking about his standards...

As an interesting aside, the only company I can think of that ever came close to cutting StellarVues prices in half was Astro-Telescopes (not Astro-Tech.) Jim Barnett has documented Astro-Telescopes is closely related to StellarVue.

Jon Isaacs

#23 CounterWeight

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Posted 22 February 2013 - 11:59 AM

At the faster focal ratios for widefield I'd also look at field flatteners if you don't aready have something that will work. This add's importance to having a focuser that can handle the extended weight.






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