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TELEVUE 102 VS TELEVUE NP101

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#1 enniot1

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Posted 02 December 2012 - 05:20 PM

Hello
My name is Ennio (from Italy). I apologize if I do not write correctly. I need help to choose to buy second hand TV102 or NP101. I read many reviews about these wonderful refractors. I think the NP101 is generally better because it is shorter and correct TV102, but I'm not sure that it is better to see the planets and double stars (sharp and clear) because the TV102 has only two lenses and a longer focal length of the NP101.

Thanks.
 

#2 Mr Onions

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Posted 02 December 2012 - 05:24 PM

Your English is better than my Italian.
Come to think of it, it's better than my English too.

You will get lots of replies from owners of these two very fine refractors.
 

#3 snommisbor

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Posted 02 December 2012 - 06:10 PM

If you are visual only the 102 would be better. The 101 is really a scope that its primary function is astrophotography. But if AP is in your future the NP101 is a great scope to have and will work visually when you want to just view the stars. I had the TV101 and it was a great scope. But I was about 80-20 AP to Visual. But if I was visual only the 102 would be what I would get.
 

#4 la200o

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Posted 02 December 2012 - 06:57 PM

I have both and am entirely visual--no AP. Both are good scopes, but if I had to choose one, it would be the NP101. With the right eyepieces and barlows, you can reach high powers with the 101, but you cannot replicate the wide field views of the 101 with the 102. Sometimes you will read that the 102, being a doublet, is brighter than the 4-lens Petzval 101. This has not been my experience, nor do I find that there is an improvement in contrast with the 102. If you have a choice, go with the NP 101.

Bill
 

#5 stevew

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Posted 02 December 2012 - 07:30 PM

An NP101 with a 30mm Nagler will give you a 4.5 degree true flat field of view. If you have access to very dark skies the views can be incredible.
If you are more interested in the Moon, and Planets go for the less expensive TV102
Both have excellent high contrast optics.

Steve
 

#6 la200o

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Posted 02 December 2012 - 10:35 PM

Another advantage of the wide field of the NP101 is that if you use it on an undriven mount (as I do), you can keep your target in the FOV for a longer time without moving the telescope. I think Steve has the right idea; if expense is an issue, the 102 costs less. Otherwise, I see no advantage to the 102. As a doublet, it probably cools down a little faster, but I doubt if that matters much in Italy.

Bill
 

#7 Jon Isaacs

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Posted 03 December 2012 - 02:44 AM

Hello
My name is Ennio (from Italy). I apologize if I do not write correctly. I need help to choose to buy second hand TV102 or NP101. I read many reviews about these wonderful refractors. I think the NP101 is generally better because it is shorter and correct TV102, but I'm not sure that it is better to see the planets and double stars (sharp and clear) because the TV102 has only two lenses and a longer focal length of the NP101.

Thanks.


Ennio:

Hello and Welcome to Cloudy Nights. :waytogo:

I own an NP-101 and I use it for double stars, the planets as well as the low power widefield views that are essentially perfect.

The TV-102 is a basic doublet, if you are interested only in high magnification views, it would be less expensive and offer very similar views. But there are other, even less expensive alternatives one should consider as well as larger scopes that would resolve tighter doubles and provide better planetary views as well.

But for me, the NP-101 is the right scope because I spend a lot of time both under dark skies as well as observing from a light polluted backyard.

Jon
 

#8 Erik Bakker

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Posted 03 December 2012 - 02:46 AM

Hi Ennio,

Are you able to see both scopes and test them before you buy them? Together, side-by-side? That will help more to make a good decision than anything else.

The NP101 has superb color correction, wide-flat fields and some I have seen where very well corrected for spherical aberration. They are a bit sensitive for getting out of collimation if you travel a lot with them. But it is a very nice and compact scope. The TV102 has a bit more color, but is fine for visual use. Some have superb spherical correction. The tube is a bit longer than the NP101. The optics in both the NP101 and TV102 are really a sample-sample thing. Test before you buy, none are equal. Some are stunning, get one of those :jump:

My FS102 has a very similar focal length to the TV102 and I find it a very versatile scope. For the lowest power widefields I use 2 eyes with my Nikon 18x70 bino. With the FS102 I start mono at 37x with my 22mm Nagler T4. The best medium power views are with the Zeiss 16.7 and 12.8 WW eyepieces. For more power than that, I switch to binoviewing. For the planets, I only observe with 2 eyes.

There was also a shorter version of the TV102, the last were named TV102is. Shorter and very well suited for bino-viewing.

Short answer: buy the best sample of the NP101/TV102 you are looking at. It will make you a very happy astronomer :)
 

#9 enniot1

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Posted 03 December 2012 - 03:16 AM

Thank you all for the answers. Tele Vue and AP have been a reference for lovers of astronomy in Italy and I think all over the world (maybe not for younger generations), so owning one of these telescopes is already a great privilege for me. We know that today there are other telescopes like the TSA 102 that are at the top and as color correction and as sharpness (perhaps unbeatable) but I think that a telescope, as well as the optical quality has to try the feelings when we look inside. (I do not know how to explain it).
In Italy, unfortunately, the cost of telescopes is very high, for example, now TVnp101 costs € 4,500, while the TSA 102 (depending on the accessories) costs between 3,300 and 3,700 Euros.
I found a TV102 with reducer / flattener and accessories to € 2,000, while a TV np101 to € 2500, but before I spend the money I would be sure to choose well.
I like TeleVue because I think he has a special charm as well as a good mechanic.
Italy is a small area but very varied, so we are seeing some good areas and other areas where the seeing is average, 5-6. It 'amazing how seeing is different after a few miles away. From a friend of mine who lives on the far outskirts of Rome, for example, Mars was still and the seeing was 8-9. When I went immediately to my house, at a distance of a few kilometers, the seeing was average 5-6.

Thanks to all.
 

#10 enniot1

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Posted 03 December 2012 - 08:36 AM

For la200 and Jon Isaacs that have NP101.
I understand that some NP101, have different diffraction images. Rings in intra focal images are clear, but in the extra focal images rings can not be seen clearly.
May depend on the optical design or is spherical aberration?
 

#11 enniot1

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Posted 03 December 2012 - 08:38 AM

Hi Erik, maybe I can try the TV102 but not the NP101.

Thanks.
 

#12 la200o

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Posted 03 December 2012 - 12:19 PM

For la200 and Jon Isaacs that have NP101.
I understand that some NP101, have different diffraction images. Rings in intra focal images are clear, but in the extra focal images rings can not be seen clearly.
May depend on the optical design or is spherical aberration?


I haven't heard about this; I did read somewhere that one owner (who greatly liked his NP101) thought he detected some spherical abberration, but then attributed it to the telescope not being properly cooled down when he began to observe.

Every now and then you will read about collimation issues with the more complex NP101, but I don't think collimation is a common problem. Tele Vue has been making Petzvals for a long time and has the bugs, if any, pretty much worked out. Both 101 and 102 are fine scopes, though, and you won't be making a mistake with either.

Bill
 

#13 Scott Beith

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Posted 03 December 2012 - 12:51 PM

I have never owned either scope but years ago I was given the opportunity to run a Tak FS102 side by side with a TV NP101. Targets such as Jupiter (high mags) and the DC (low mags) were selected. After many back and forth observations the NP101 edged out the FS102 (but it was REALLY close). This was only with one sample of each scope and might not be indicative of results obtained from a larger pool of samples. I would be thrilled to own either the TV102 (which should be right in line with my SV102V LOMO) or the NP101 if I didn't already have the SV.

A high quality 4" apo is a heck of a nice scope. :)

Either way you will be happy.
 

#14 jrbarnett

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Posted 03 December 2012 - 01:01 PM

Ennio:

For visual use as you describe, I would go with the TV-102. The TV-102 is less sensitive to alignment and centering errors, cools more quickly, has greater depth of focus, costs less, holds its value better used, doesn't require Barlows to achieve highest useful magnification, has little field curvature visually at a slow f/8.6 and actually weighs a bit less. Likewise, the NP-101 is not a short scope. Because it's a Petzval, it is much longer than a 101mm f/5.4 doublet would be, and is only a little shorter than the TV-102.

Unless you are a nut for ultra wide true fields of view, I can't see much reason to invest in an NP-101 as a visual use instrument. If you do buy an NP-101, though, buy used. They depreciate enormously from new.

Regards,

Jim
 

#15 Jim Romanski

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Posted 03 December 2012 - 01:06 PM

I want to make sure that some of the previous posts are not lost in translation. Folks here on CN (Cloudynights) tend to abbreviate quite a lot.

When someone writes "80-20 AP to Visual" they are saying that 80% of the time they use the telescope for AP (Astrophotography) and 20% of the time to look through it visually.

They are NOT referring to AP (Astrophysics) Refractor Telescopes.

I have an NP101 and it's a wonderful versatile telescope. I can see wide fields and high power. I can also do widefield Astrophotography with it if I wish.

The TV102 is very well corrected for false color but not as good as the NP101. Other than that the main difference is that you won't get quite as wide a field of view with it.
 

#16 enniot1

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Posted 03 December 2012 - 04:57 PM

This is one of a star test NP101. As you can see the pictures intra / extra are very different.

Attached Files


 

#17 enniot1

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Posted 03 December 2012 - 05:12 PM

You're right Erik, perhaps the Televue are not all the same, because here in Italy I heard positive feedback but also negative. It's possible?
 

#18 John Rhodes

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Posted 03 December 2012 - 06:45 PM

This is one of a star test NP101. As you can see the pictures intra / extra are very different.

This picture is in no way indicative of an NP 101, or NP 101is
I have had several and currently have two (one of each) that I use at star parties and
I can get near if not identical diffraction patterns on each side of focus visually.
 

#19 la200o

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Posted 03 December 2012 - 07:13 PM

Maybe I'm repeating myself, but I own both and if I had to choose I'd take the NP101 in an instant and sell the 102. Don't really know why I keep the 102, except that I don't need the money, like having a backup scope, and am sentimentally attached to the old 102, which was my first good 4" refractor. The collimation problems have been IMO exaggerated and I find the NP101, despite its shallower depth of field, just fine even with the older one-speed focuser (and now of course it comes with a really good two-speed). Cool down will not be much of an issue. Although any mount that will handle the 102 will handle the 101 and vice versa, I find the shorter tube of the 101 a better match for the mount I use for them (a Half Hitch Mark III).

Jim Barnett is certainly right that it can be very advantageous to buy used, since depreciation is considerable, but with the notable exception of Astrophysics telescopes, this is pretty true of apo's in general. I haven't followed TEC prices much, but Tak FS and TSA 4" scopes depreciate significantly as well, though there are fewer of them out there and therefore harder to find used.

Here's how I see it: TV 102, cheaper than the 101, and that's about it as far as real advantages go. Will you notice a great difference visually with the NP101? Probably not, but you will lose the (to me) great advantage of the NP's wide, flat field (unbeatable for open clusters), the essentially perfect color correction of that scope (not that the 102 is at all bad), and the knowledge that you've got the best telescope that TV has produced so far.

But again, you can't really go wrong. I used and continue to use my 102 with great satisfaction.

Bill
 

#20 jrbarnett

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Posted 03 December 2012 - 08:18 PM

That's not all that unique or unusual for a Televue Petzval's star test.

See these NP-127 images showing similar softness on one side of focus.

http://tinyurl.com/czzsgo9

Disregard the folks blaming seeing. Seeing affects BOTH SIDES OF FOCUS. Only one side of this optic is really soft.

Peruse these, too:

http://aberrator.ast....net/scopetest/

See this example specifically:

http://aberrator.ast...actor100_4.html

There are mixed bag results for TV-102s, too, though. I've owned one and looked through a bunch of TV-102s, and all are not created equally. Rohr has a test for one with a zone. It's still a decent optic in the final analysis, but not as good as other TV-102s. It's worth noting, though, that I've seen more "middlin" Televue Petzvals than doublets. That's not to say that I haven't seen Televue Petszals with nice optics too. I have. Two out of six that I've had a chance to play with and star test a bit. It was my experiences with other people's NPs that lead me to opt for the doublet instead. :shrug:

Regards,

Jim
 

#21 la200o

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Posted 03 December 2012 - 09:20 PM

Though he may not be a fan, Jim seems to be outvoted by the many favorable reviews and enthusiastic users of the NP101.

Bill
 

#22 cloud_cover

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Posted 03 December 2012 - 11:46 PM

Hello!
I think the most important question is do you ever intend to stick a camera into the telescope? If yes, then the NP-101 is the best choice (actually the only choice unless you like to play with field flatteners, which adds cost to your whole setup anyway)
I personally use the NP-101 for both visual and AP. I find its contrast is excellent and looking at stars through it is almost sublime, compared with a previous 80ED doublet I had an a current 8" SCT (The SCT is undoubtedly brighter, but the NP-101 view is nicer)
I'd also like to point out that although the TV-101 has a longer focal length, this difference can be compensated for by using shorter focal length eyepieces. They both have (roughly) the same maximum useful magnification anyway)
How much is the difference in price, used? If its not significant, then I suggest going for the NP-101 instead.
 

#23 KWB

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Posted 04 December 2012 - 12:01 AM

Though he may not be a fan, Jim seems to be outvoted by the many favorable reviews and enthusiastic users of the NP101.

Bill

Everybody is entitled to their opinion,and no, we aren't running an election in this thread,nor do we need to make reference to anothers likes or dislikes. One persons eye for beauty can be anothers eyesore.

Stating your viewpoint once, on-topic and in a civil manner, in a thread is usually sufficient. :cool:
 

#24 la200o

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Posted 04 December 2012 - 07:58 AM

I fail to see how my comment is uncivil.

Regards,

Bill
 

#25 Lt 26

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Posted 04 December 2012 - 08:01 AM

1) the 102 cost less, a lot less new, a few Ethos less.

2) the 102 is shorter and lighter than a 101 with a Barlow.

3) you can drop kick a 102 across a field and the only damage would be to your foot.

Dereck
 






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