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Televue 85 vs. Televue NP101

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#51 Jon Isaacs

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Posted 02 January 2013 - 08:38 PM

But I have to say that I considered mag 12 galaxies (the unlabeled ones in Atlas Coeli 1950.0) to be about my absolute limit with the 8-inch. Maybe I gave up too easily on fainter ones simply because no atlas I owned showed them.



I am not saying I can see every 11th or 12th magnitude nebula or galaxy but there are some I can see... But I start with ones I know already in a larger scope.

At 64, I am afraid my eyes are not what they once were, that's one reason I hunt these things down, it gives me a little reassurance that there is still some gas left in the tank..

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#52 cloud_cover

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Posted 03 January 2013 - 10:41 AM

I would dearly love to see Jupiter's moons resolve to disks, for example, and realize that a 3 or 4 inch scope is not likely to get me there. Still, those wide views..,

I use the NP-101 with an Ethos SX 3.7mm. Adding Jon's 2x GSO barlow lens (without the extension) gives about 220x. I see Jupiter's moons clearly as nice round discs, not points :)
Personally, I think unless portability is an issue, go with the NP-101. It does fabulously wide views (I don't think there's any scope out there than can match it for widest-sharpest-field ) If cash is an issue, then truly other scopes would be better than the TV-85.

#53 Jon Isaacs

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Posted 03 January 2013 - 11:21 AM

I would dearly love to see Jupiter's moons resolve to disks, for example, and realize that a 3 or 4 inch scope is not likely to get me there. Still, those wide views..,

I use the NP-101 with an Ethos SX 3.7mm. Adding Jon's 2x GSO barlow lens (without the extension) gives about 220x. I see Jupiter's moons clearly as nice round discs, not points :)


The difficulty is that stars do not resolve to points but rather round disks and this can be clearly seen in a 4 inch scope at 220x. The Raleigh Criteria for a 4 inch scope is 1.36 arc-seconds, about the size of Jupiter's largest moon. The additional difficulty is that the size of the disk depends on the brightness of the object. Consider an unequal double star like Castor, both the primary and the secondary are points sources but the secondary is about 1.4 magnitudes dimmer and when magnified, the Airy disk appears smaller.

In a 4 inch scope, a point source like a star resolves to a disk about the size of Jupiter's largest moon, a moon is seen as something larger than this, but it is dependent on the brightness. Thus, seeing disks of varying size is not sufficient to "resolve" the moons of Jupiter.

Jon
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#54 BillP

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Posted 03 January 2013 - 04:41 PM

Bill, is the 92SS of similar build and visual quality?
Thanks,
Chuck


Would put its build quality a notch lower than the TV as TVs are built like tanks. But the build is still excellent on the TMB. Optically I would say they are all very good. TV85 is a doublet and some folks report they can coax a very little color out of now and then. NP101 essentially color-free. TMB had a little color as it is a super-fast triplet. NP would be a more complicated re-collimation given it's dual doublet design, other two perhaps a bit simpler if needed (TMB is meant for user collimation, TVs are built for it to be done at factory).

NP is really in a class of its own and should IMO be considered as such due to its optical design - Petzval. It produces a flat field whereas doublets and triplets do not. You might gets some field curvature visible at the eyepiece for low power ultrawides with the TMB, not with the NP. If optical performance were the ONLY deciding factor then would go with the NP as it has the unique flat field, very fast focal ratio. But since portability and simplicity are prominent goals for you, and aperture as well to some degree, the others come into the mix. For me, if just a choice between the 85 and the 92, I would go with the 92 because smaller and wider field and more aperture...simply more versatile than the 85. Plus the TMB92 (not the L version) has Starlight focuser which puts most focusers to shame, and still $350 less than the 85. If you go with the L version then $850 less than the 85. So could get the 92L with a battery of fine eyepieces and have more TFOV and more aperture than just the 85. To me, the choice is between the 92SS and the NP101. If I was going to make the refractor I buy my only largest refractor, then would probably opt for the NP101 if could afford. If I anticipated getting a 120mm or 130mm APO in the future, then that would steer me directly to the 92 as would never need an 80mm for travel since the 92 is so very small and a 101 is IMO just too big to keep with a 120 or 130 APO also. It is s always more about other things than purely optics.

#55 Erik Bakker

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Posted 03 January 2013 - 05:06 PM

It is s always more about other things than purely optics.


Very true Bill :bow:

#56 John Rhodes

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Posted 03 January 2013 - 11:25 PM

NP would be a more complicated re-collimation given it's dual doublet design,

Tele Vue scopes only need tilting of the front cell to collimate... like most scopes, the rear elements cannot move in their cell.


if just a choice between the 85 and the 92, I would go with the 92 because smaller and wider field and more aperture...simply more versatile than the 85. Plus the TMB92 (not the L version) has Starlight focuser which puts most focusers to shame, and still $350 less than the 85.


All Tele Vue scopes come with custom Starlight Feathertouch 10:1 Rack & Pinion focus assemblies... except the TV 60 "is"

#57 Mark9473

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Posted 04 January 2013 - 06:46 AM

In a 4 inch scope, a point source like a star resolves to a disk about the size of Jupiter's largest moon, a moon is seen as something larger than this, but it is dependent on the brightness. Thus, seeing disks of varying size is not sufficient to "resolve" the moons of Jupiter.


Well as long as I'm seeing dimmer Callisto as a larger dot than the brighter Io and Europa, you're not convincing me that I'm not seeing the size differences between the jovian moons. Did this in a 90mm achromat many years ago, and more recently in my 107mm apo. But it helps to be close to opposition, when the moons are just a bit larger.

#58 Balok

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Posted 12 February 2015 - 07:49 AM

I have considered these 2 as well.

 

For my wide field purposes, the NP 101 get's the call. Increased aperture, hard case and optimal field of view range for my eye piece line up.

 

The 70 mm Pronto with Nagler's  gives beautiful, fantastic & stunning views, yet as other note, there  can be " what if I went bigger  and what am I missing now' element.

 

But either way it's the views of a lifetime and they will be shockingly good IMHO.

 

Good luck



#59 choran

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Posted 12 February 2015 - 02:02 PM

Blast from the past!  I started this thread three or four years ago when I was trying to decide on an 85 or an NP101

Ended up with--both!  LOL  And love 'em both.  If portability is an issue, I'd go with the 85.  If pure performance is the criteria, then the NP101 gets the nod.  Both are great, and as many have pointed out, the build quality is very very good.  Both scopes are a pleasure to use, very smooth, and very solid.  I probably use the 85 a bit more, as I just leave it set up on a tripod so I can pick it up and carry out the door when I want to observe for a short time.  NP101 is not difficult to set up, but I use it on a heavier mount and it is not set up ready to go. 


Edited by choran, 12 February 2015 - 02:04 PM.

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#60 Markab

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Posted 15 February 2015 - 07:44 AM

That's great!  I've owned three TV-85s and one TV-102. Each had its own attributes...obviously the 102 could pull in a bit more and seemed to have a bit less chromatic aberration (f/8.6 v. f/7), but the TV-85 was very portable and fun to use. I also felt that the tube construction was a bit thicker/more robust on the 85's.  I ended up using my 85's more because of the "fun" aspect and great wide field views.


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#61 la200o

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Posted 15 February 2015 - 09:34 AM

Maybe I need a TV-85 . . . 


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#62 NHRob

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Posted 15 February 2015 - 10:29 AM

YES YOU DO !



#63 ypsiladdie

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Posted 15 February 2015 - 02:10 PM

What a great resolution to this thread.  I had an 80mm refractor first, then the 102mm.  Did the larger scope throw down better images? Yep.  So much better that the 80 was obsolete?  Nope.  And the 80 packs in half the space of the 102; a true advantage on vacation.


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#64 Balok

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Posted 15 February 2015 - 02:12 PM

Thank you for your update Choran ...  it helps me decide on an NP 101 especially since I have a 70 mm Pronto...  a TV Gibraltar is in place, Naglers ready to go.

 

Other  4 "  wide field APOs were considered but  many require a different mount head /plate or tripod... thus all roads led back to the NP... probably pull the trigger in late May - early June.

 

Thanks again

 

Balok


Edited by Balok, 15 February 2015 - 02:15 PM.

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#65 kenpo154

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Posted 15 February 2015 - 07:33 PM

I own a TeleVue 85 ,and just love the grab and go. I have only looked through a TV101 a couple of times at the stellafane convention in Springfield Vt.  The little 85 did pretty good when compared to the view thru the 101. The brighter nebulas views were surprisingly very similar. I use the Telepod on a 3211 Manfrotto tripod for grab and go , a Vixen GP mount with SkySensor go to.

 

David



#66 kenpo154

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Posted 15 February 2015 - 07:35 PM

TeleVue 85

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#67 Mary

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Posted 15 February 2015 - 08:59 PM

I am fortunate to own a family of Televue.   An NP101, a TV 85(husband's scope), a Pronto and a Ranger.  All of them are fabulous scopes!  My Pronto is the one that sees the most use as a quick grab and go on a Telepod tripod and mount.

 

Mary


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#68 alnitak22

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Posted 16 February 2015 - 08:34 AM

 

Beautiful set-up!



#69 alnitak22

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Posted 16 February 2015 - 08:42 AM

I own a TeleVue 85 ,and just love the grab and go. I have only looked through a TV101 a couple of times at the stellafane convention in Springfield Vt.  The little 85 did pretty good when compared to the view thru the 101. The brighter nebulas views were surprisingly very similar. I use the Telepod on a 3211 Manfrotto tripod for grab and go , a Vixen GP mount with SkySensor go to.

 

David

 

Yes, I agree. I've had my TV85 side by side with 4" apos from Tak, TV, and Vixen over the years. The bigger scopes definitely had an advantage, but the margin was smaller than I would have thought. In fact, the margin between my 70mm Ranger and my 85 is larger than the margin between the 85 and 102s. But in a side by side with an NP127...well, that was the large difference I was expecting.



#70 Balok

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Posted 16 February 2015 - 01:31 PM

To my mind, the TV 85 is a benchmark of  outstanding telescope performance.

 

Whoever the owner, wherever their location and  whatever their conditions , I'm not sure I've read a bad review - ever and the net has a great many.

 

That is impressive. 


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#71 Jon Isaacs

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Posted 16 February 2015 - 02:21 PM

My own story/thinking:

 

My first really decent refractor was a Pronto and I had a lot of fun with it. It introduced me to birdwatching and digiscoping, I took thousands of photos of birds with it.. (see photo below)  When the ED-80 came along and scopes with excellent color correction came along, I started down that path.. The Pronto is a great little scope but the chromatic aberration messed up enough photos of birds that I wanted something better corrected for color.  

 

The ED-80 was excellent optically but way big to replace the Pronto.. The ED-80 was replaced by a William Optics 80mm F/7 Megrez II FD and that has been a favorite scope, every once in a while I ponder the TV-85 but the William Optics is excellent optically and mechanically and I cannot justify the cost for the small increase in aperture.. 

 

The search for the perfect small refractor led me to the Astro-Tech 102ED and I knew I was close, it was the right size and a very competent scope but I enjoyed it so much, I wanted something more perfect.. Tom Trusock's review of the NP-101 convinced me that was what I wanted so about 5 years ago I picked up my NP-101 and it's been a perfect scope for me, out under the dark skies, it a perfect companion for a large scope and in the backyard, it's handy-dandy and an excellent performer at high magnifications..

 

But the hole left by the Pronto's leaving was never filled. I couldn't justify both the Pronto and the ED-80 so I sold the Pronto, Attilla Danko of Cleardarksky.com bought it.  I bought a William Optics 66SD but the lack of the 2 inch focuser and there wasn't just enough aperture..  So, I actually gave that one away to someone who had serious health issues... 

 

But recently I bought a Astro-Tech AT-72 ED and that seems to have filled Pronto's role, it's just so small and handy and has quite good optics, I splitting Eta Orionis with it, 1.7 arc-seconds, the Dawes limit is 1.61arc-seconds.. A TeleVue 76 could replace it and maybe the William Optics 80mm FD but it would cost some real money and I have history with these scopes.. 

 

Jon

3866678-says phoebe 1.jpg

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#72 Mary

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Posted 16 February 2015 - 05:08 PM

Beautiful photo Jon!  My Pronto and Ranger both do double duty as astro scopes and birding scopes.  I love small scopes too much to ever be without one and a Pronto was my first refractor.   I am on my second Pronto, a few years ago I got aperture fever and also wanted better color correction, I sold my Pronto and instantly regretted it.  The one I have now also has a Feather-touch micro-focuser on it and it is even better than my first one. 

 

The NP101 was my dream scope and I was very, very lucky to buy a near new one in mint condition years ago.  It is everything I ever wanted and only took a brief hiatus in action when my two dogs were young pups and I didn't want to risk them knocking it down.  I love Televue scopes, their optics, their mechanics, the way they look, everything.  And then, there are those wonderful eyepieces.....

 

Mary


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#73 JoeBftsplk

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Posted 26 February 2015 - 11:35 PM

OP: You say you want to get something your children will appreciate and use when you pass it on. Are they interested in astronomy? If so, the NP101 would be a great choice.

But, if they're not, they may still be interested in terrestrial viewing, birding, wildlife viewing, travelling and seeing the sights up close (closer anyway), or maybe to look for bullet holes in a target 100 yd. away. If this is more likely, the TV85 will be the winner. Much easier to transport and set up. Less likelihood of unintentional damage and generally easier to live with. If they are not astronomers, the kids will be more likely to hang onto a TV85 and use it for whatever furthers their interests.

I have a TV76 and an NP101. The TV76 is the easy versatility winner.
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