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Televue "imaging system"


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I always wondered why televue renamed NP101 and 127 to NP101is and 127is. Why did they want to include the term "imaging system" in the name of the long lived NP scopes at all costs? Why call "imaging system" a refractor like NP that has always had a visual vocation? Wasn't it better to leave the original name without referring to the imaging "world"? Is the NP is only a photographic telescope and not so suitable for observation?

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I found this on Roger Vine’s Scopeviews site which explains it:

NP101 or NP101is?

The ‘is’ stands for ‘Imaging System’. The two NP101s I have owned have been the standard visual versions. These differ from the NP101is in two key areas

1)     The NP101is has a larger focuser with features suited to CCD work: a larger draw-tube, a built-in micro-focuser and a visual back with four set-screws for perfect centring and a plate that allows small adjustments of tilt so you can get your camera perfectly aligned to the optical axis.

2)     Perhaps more significantly, the imaging system version has a larger Petzval lens to minimise vignetting (loss of brightness at the field edge), which is otherwise a problem with Petzvals.

If you want to image with a full-frame chip, then you will need the i.s. version. For visual use, or smaller sensors, the standard version will likely be just fine.

http://www.scopeviews.co.uk/TVNP101.htm

 

There’s no reason you couldn’t use an ‘is’ for visual, but it is not necessary/won’t improve the visual views.

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One time there was the NP and the NPis. One could choose. Then, suddenly, the NP disappeared and only the IS version remained. Wasn't it better to leave the original name? I think that amateur astronomy is now only dominated by imagers. And this choice seems prove it.

 
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I had a chance to speak to Al Nagler recently. I have the NP101is and asked the questions about not keeping two scopes. His answer was that it came down to economics. The majority of people buying a 101 and 127 were imagers. They wanted the additional features. Visual users have the option to buy the IS versions but not the old version. 

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On 04/01/2022 at 22:18, Dr Strange said:

I had a chance to speak to Al Nagler recently. I have the NP101is and asked the questions about not keeping two scopes. His answer was that it came down to economics. The majority of people buying a 101 and 127 were imagers. They wanted the additional features. Visual users have the option to buy the IS versions but not the old version. 

Thank you for sharing.

Well, I always thought this was the real reason. despite what televue claims, for the visual observer it is not the same thing (and the same pleasure) to use a refractor optimized for photography. it is a compromise, and for the price with which it is sold in my opinion it is not acceptable. it seemed to me a "downside" decision and a sort of "betrayal" of the basis of the televue philosophy which has always been dedicated to the visual experience. For this reason I went to Takahashi instead Televue. It's quite a shame.

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Actually, probably most that buy the scope are imagers, and maintaining a separate SKU for those who did not want the IS version probably has a higher cost for Tele Vue, so they sell the IS versions, which are of course suitable for visual (and then some!), but which won't vignette due to the larger focuser, thus suitable for imagers.

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On 05/01/2022 at 00:03, 883 said:

Thank you for sharing.

Well, I always thought this was the real reason. despite what televue claims, for the visual observer it is not the same thing (and the same pleasure) to use a refractor optimized for photography. it is a compromise, and for the price with which it is sold in my opinion it is not acceptable. it seemed to me a "downside" decision and a sort of "betrayal" of the basis of the televue philosophy which has always been dedicated to the visual experience. For this reason I went to Takahashi instead Televue. It's quite a shame.

Cheers.

As an aside, I am not sure why your response came through at 24 point font and highlighted. I was able to reduce it but not eliminate the white highlight. I am afraid my Stargazerslounge Kung Fu has failed me... ;)

I would disagree regarding visual vs. imaging using the AP optimized scopes (key caveat) in the case of Tele Vue and Skywatcher. I regularly use my NP101is for visual and have used a Skywatcher Esprit 100 as well. My TV is able to capture the entire Veil complex in a 31 Nagler. Something impossible in other scopes. My NP worked out of the box. Stuck a 2" diagonal up its bum, put several different EP's in it including the aforementioned 31 Nagler, and off to the races I went. It works very very well for wide field sweeping visual work and visual work on large DSO. It even did well pushing power on planets.

I pushed all the way up to 180x using a 3-6 TV click zoom at 3mm. It was the highest I could go without a Barlow. Saturn was crystal clear with excellent color. I think I could have pushed the scope all the way up to 360x if I had a decent Barlow with me. Seeing was above average but not excellent. I was patiently waiting for those moments of clear quiet stable air and was rewarded for it. 

I will also say that Takahashi imaging scopes are quite over priced (especially with the almost fetishized bits and bobs needed to get one  where it is able to image properly) to use as a visual scope and also not a great visual scope. I did not use the FSQ106 but did try it with the FSQ85. I simply gave up. The amount of fiddling I would have to do including purchasing of special attachments and a diagonal and the limitations on eyepieces was completely ridiculous. 

For the record I am a big Tak fan. I have the FC-60Q and 76Q (courtesy of a Frankenscope design from the gentleman at Alpha Lyre who did it), a TSA-120 and Mewlon 210. I have had in the past a TOA-130, TOA-150, and Mewlon 250 in addition to the aforementioned FSQ85. I am very sensitive to CA. CA drives me to distraction. And want the best color correction I can have. Thus doublets, even well corrected ones, for the most part are not an option for me and I can see the difference in color correction. I compared a Astro Physics 155 EDFS to my TOA 150 and the TOA 150 had a minimal but noticeably better color correction to it.  So Tak is my platform of choice for most things. I explain to She Who Must Be Obeyed that while astronomy is expensive it is far less expensive than other hobbies and it keeps me out of the Pubs. 

I also have a huge bugaboo about oil spaced scopes. I have personally seen 5 TEC 140's have problems that required them to be sent back and redone. In the grand scheme of things if I settle on a refractor I tend to stick with it and will keep it for many years. I do not want to worry about seals going south or oil leaks/settling. Especially when the person(s) who are most qualified to restore the scope to its original state may be retired or, God forbid, passed on.

I gave up the 130, 150, and 250 because of some medical issues I suffered. But SWMBO has subsequently agreed to my setting up something permanent in the back yard. Oh how I *WISH* she had done so before I sold my kit! I am now considering what to get. 

 

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23 hours ago, Dr Strange said:

Cheers.

As an aside, I am not sure why your response came through at 24 point font and highlighted. I was able to reduce it but not eliminate the white highlight. I am afraid my Stargazerslounge Kung Fu has failed me... ;)

I would disagree regarding visual vs. imaging using the AP optimized scopes (key caveat) in the case of Tele Vue and Skywatcher. I regularly use my NP101is for visual and have used a Skywatcher Esprit 100 as well. My TV is able to capture the entire Veil complex in a 31 Nagler. Something impossible in other scopes. My NP worked out of the box. Stuck a 2" diagonal up its bum, put several different EP's in it including the aforementioned 31 Nagler, and off to the races I went. It works very very well for wide field sweeping visual work and visual work on large DSO. It even did well pushing power on planets.

I pushed all the way up to 180x using a 3-6 TV click zoom at 3mm. It was the highest I could go without a Barlow. Saturn was crystal clear with excellent color. I think I could have pushed the scope all the way up to 360x if I had a decent Barlow with me. Seeing was above average but not excellent. I was patiently waiting for those moments of clear quiet stable air and was rewarded for it. 

I will also say that Takahashi imaging scopes are quite over priced (especially with the almost fetishized bits and bobs needed to get one  where it is able to image properly) to use as a visual scope and also not a great visual scope. I did not use the FSQ106 but did try it with the FSQ85. I simply gave up. The amount of fiddling I would have to do including purchasing of special attachments and a diagonal and the limitations on eyepieces was completely ridiculous. 

For the record I am a big Tak fan. I have the FC-60Q and 76Q (courtesy of a Frankenscope design from the gentleman at Alpha Lyre who did it), a TSA-120 and Mewlon 210. I have had in the past a TOA-130, TOA-150, and Mewlon 250 in addition to the aforementioned FSQ85. I am very sensitive to CA. CA drives me to distraction. And want the best color correction I can have. Thus doublets, even well corrected ones, for the most part are not an option for me and I can see the difference in color correction. I compared a Astro Physics 155 EDFS to my TOA 150 and the TOA 150 had a minimal but noticeably better color correction to it.  So Tak is my platform of choice for most things. I explain to She Who Must Be Obeyed that while astronomy is expensive it is far less expensive than other hobbies and it keeps me out of the Pubs. 

I also have a huge bugaboo about oil spaced scopes. I have personally seen 5 TEC 140's have problems that required them to be sent back and redone. In the grand scheme of things if I settle on a refractor I tend to stick with it and will keep it for many years. I do not want to worry about seals going south or oil leaks/settling. Especially when the person(s) who are most qualified to restore the scope to its original state may be retired or, God forbid, passed on.

I gave up the 130, 150, and 250 because of some medical issues I suffered. But SWMBO has subsequently agreed to my setting up something permanent in the back yard. Oh how I *WISH* she had done so before I sold my kit! I am now considering what to get. 

 

Thank you for sharing your experience.

I have no doubt that TV telescopes are very good but I'm a visual purist and so I prefer to use a visual optimized telescope like many wonderful Takahashi (and yes, I disagree about Tak doublets, FC 100 DL, for example,  is much better than many other  famous telescopes from other very famous producers.... IMO of course). 

It's just a shame, in my vision, that amatorial astronomy is now totally dominated by imagers, and so producers are all going to that direction. It's painful for me seeing so many companies changing approach and philosophy. Just my opinion.

 

 

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I bought a TV NP101 IS about 13 or 14 years ago. Televue claimed that "It Is What You Want It To Be!" Unfortunately it wasn't what I wanted it to be, which was a lunar and planetary scope in an easy to handle package. I know many would argue the NP101IS gives great views of the Moon and planets, but they are just ok from my perspective. It was an expensive scope that couldn't deliver the same crispness of planetary image delivered by a much cheaper Vixen ED, so I sold it. It was however a stunning visual RFT, the best I've ever used. I think its lack of planetary punch is in part down to its short F ratio, plus four elements combined with the multi element Nagler eyepieces and powermate needed to reach an acceptable magnification. All the above takes the edge off the definition that's so vital for planets. Having said all that, the sketch of Mars in my avatar was drawn through my NP101 IS.

I did like the 101 for its visual rich field capabilities, in fact I loved it, but I needed a top class planetary scope, so in that sense I feel Televue grossly exaggerated their claims regarding the scope. Their philosophy really is the "Space Walk" experience, and in that regard their scopes really stand out and shine. I recently bought a vintage Genesis SDF for a fraction of the price of a new NP101IS. Although it isn't truly Apochromatic, it is everything I loved about the NP101 IS,  its star images are textbook perfect with no hint of spherical abberation, and better than the IS I owned. So buying an older TV scope second-hand may be the better option. I know the optics for the earlier TV refractors were made in Japan but I'm not certain that is still the case. Perhaps others may enlighten me?

 

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I haven’t used a 101, so speaking somewhat theoretically, but agree with Mike. I wouldn’t expect an F/5.4 scope to really shine as a lunar and planetary instrument. Even if colour correction was top notch, a fluorite doublet at F/8 or F/9 would always be preferable. And the NP101 is £4K. For that money, a Tak TSA-120 comes into play. I love Televue’s build quality, but struggle to see a visual market for its larger refractors

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On 12/01/2022 at 13:48, 883 said:

Thank you for sharing your experience.

I have no doubt that TV telescopes are very good but I'm a visual purist and so I prefer to use a visual optimized telescope like many wonderful Takahashi (and yes, I disagree about Tak doublets, FC 100 DL, for example,  is much better than many other  famous telescopes from other very famous producers.... IMO of course). 

It's just a shame, in my vision, that amatorial astronomy is now totally dominated by imagers, and so producers are all going to that direction. It's painful for me seeing so many companies changing approach and philosophy. Just my opinion.

 

 

As a visual purist I think you would be very satisfied with the quality of the NP101is as a strictly visual scope. It is made for imagers but the fact that it is designed for imagers but retains its ability to do visual very very well is a big plus. But for visual I would only use it for wide field work and I do. In addition it has a high cost for a 101mm telescope. For not much more the TSA-120 is a better option overall.  If I want something with more oomph then it is the TSA-120. The color correction on it is very slightly below the TOA series but at significantly less weight and cost. 

I haven't used a FC 100 series yet but am told that it is very well corrected. I am very pleased with my FS-60Q/76Q in terms of color correction and CA. Even at its native f/5.9 355mm focal length. CA is there at its native configuration without the Q module but it is tolerable to me. In addition it is a fantastic grab & go as well as airline portable scope. I have mine kitted out for both outreach (I am a NASA/JPL Solar System Ambassador) and for air travel. Before I had to lug a trolly with all my kit in it and it was a royal pain. Now everything fits on my back. I can have two scopes working at the same time and be on two different objects or have one setup for EAA for everyone in line to use their smartphones to look at things then come up to the eyepiece to view it live. I also have a solar Ha and white light setup for daytime outreach. I will do spontaneous sidewalk outreach and more formal ones at schools, libraries, etc. Before the pandemic I was doing at least one outreach event a month and sometimes 2-3. I only recently started back up again.

I have two AZ-GTi, a complete Solar Ha and white light kit, a EAA kit, and the 60 and 76 in a camera backpack that goes in overhead bins or under the seat no problem. It plus my roll on suitcase mean no checked luggage and I am within even the strictest airline luggage requirements. 

If someone is looking for a excellent doublet and wants a Takahashi I strongly recommend the FS-60Q. 

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1 hour ago, Dr Strange said:

As a visual purist I think you would be very satisfied with the quality of the NP101is as a strictly visual scope. It is made for imagers but the fact that it is designed for imagers but retains its ability to do visual very very well is a big plus. But for visual I would only use it for wide field work and I do. In addition it has a high cost for a 101mm telescope. For not much more the TSA-120 is a better option overall.  If I want something with more oomph then it is the TSA-120. The color correction on it is very slightly below the TOA series but at significantly less weight and cost. 

I haven't used a FC 100 series yet but am told that it is very well corrected. I am very pleased with my FS-60Q/76Q in terms of color correction and CA. Even at its native f/5.9 355mm focal length. CA is there at its native configuration without the Q module but it is tolerable to me. In addition it is a fantastic grab & go as well as airline portable scope. I have mine kitted out for both outreach (I am a NASA/JPL Solar System Ambassador) and for air travel. Before I had to lug a trolly with all my kit in it and it was a royal pain. Now everything fits on my back. I can have two scopes working at the same time and be on two different objects or have one setup for EAA for everyone in line to use their smartphones to look at things then come up to the eyepiece to view it live. I also have a solar Ha and white light setup for daytime outreach. I will do spontaneous sidewalk outreach and more formal ones at schools, libraries, etc. Before the pandemic I was doing at least one outreach event a month and sometimes 2-3. I only recently started back up again.

I have two AZ-GTi, a complete Solar Ha and white light kit, a EAA kit, and the 60 and 76 in a camera backpack that goes in overhead bins or under the seat no problem. It plus my roll on suitcase mean no checked luggage and I am within even the strictest airline luggage requirements. 

If someone is looking for a excellent doublet and wants a Takahashi I strongly recommend the FS-60Q. 

Hi Doctor Strange,

thank you again for sharing your experience.

I just can say that if you have the chance, try the Tak FC100DL, truly amazing. It is a bit long, yes, but it is quite light and, most importantly, viewing through this scope is a real experience...  Native fluorite f/9 optic, wonderful!

Surely the TV is a good telescope but an hybrid instrument it's just not for me, for this reason I went to Takahashi. And I'm absolutely enthusiast with it. 

Hope that TV can return to offer truly visual telescopes in the range of 100+ mm. Maybe with some optical innovation, who knows... I could get one!

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I do like the clean look of Televue scopes, and may be if I'd bought a TV 102 instead of a NP101IS,  I'd still be using it. From memory though, the 102 wasn't cheap, especially for an ED, and I felt there were other beautiful doublets on the second-hand market for less  that could possibly run it ragged. 

I think today if I wanted an RFT visual quad that could perform on the Moon and planets, and could afford it, I might possibly go for a FSQ106. Then again I'd most likely forfeit the 5° field and go for an off the shelf Starfield 102, Vixen 103 ED, or Tak FC and save a small fortune.

Edited by mikeDnight
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I’m sure the TV102 is a very nice scope, but used prices seem very high compared with other, likely better alternatives such as the Vixen 103S. I seem to have ended up with three lovely four inch scopes covering all based, TV Genesis f5 for those 5 degree flat fields, the FC100DC f7.4 as a great all rounder and the Vixen FL102S f8.8 for higher power. Obviously having one scope that did it all would be great, but then what would my excuse be for owning these? 🤪🤣

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I remember some time ago (I think early 2000s) an interview with Al Nagler. When asked what he preferred for pure visual observation between the TV102 and the TV 101 he answered the TV102 (less glass, better view). I was surprised about that statement (so 4 elements are too much ?) but I think that it is true. Also, in a recent interview in Binomania web site, he also said that TV will never offer again such type of scope (visual doublets like the 102) just because there is no market for that type of instrument. Sad news.

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3 minutes ago, 883 said:

.... TV will never offer again such type of scope (visual doublets like the 102) just because there is no market for that type of instrument....

I think a number of other brands have disproved that.

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10 minutes ago, 883 said:

I remember some time ago (I think early 2000s) an interview with Al Nagler. When asked what he preferred for pure visual observation between the TV102 and the TV 101 he answered the TV102 (less glass, better view). I was surprised about that statement (so 4 elements are too much ?) but I think that it is true. Also, in a recent interview in Binomania web site, he also said that TV will never offer again such type of scope (visual doublets like the 102) just because there is no market for that type of instrument. Sad news.

I think it depends what you are after. The beauty of TV Petzvals is their wide, flat fields, that’s what they do differently. Most other Petzvals are more dedicated imaging scopes I think. My old Genesis does one thing brilliantly, 5 degree flat field views which are difficult to reproduce with anything else. The TV102 has a lot to compete with, Vixens, Taks etc.

I do wish Televue would be as innovative with their scopes are they are with their eyepieces. It would be great to bring out something cutting edge and leading in terms of optical quality, I feel they are just a smidge behind Tak/AP/TEC etc which is at odds with their eyepiece positioning in the market.

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You only have to see the flood of visual doublets hitting the market now to show how out of touch that statement is about there being no market for them.

Dare I raise the subject of TV undercits. 😁

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Don't get me started on TV undercuts. I hate them! 

What Al probably means is that TV profits won't be as high as he'd like them to be on a visual refractor, though I do think there would be a significant following who would buy Televue if they were available. They like to charge high prices for everything, though you may not have noticed.

Just going back to the NP101IS, by reading user experiences on CN, there appears to be a consensus that as the power increases the image softens. Perhaps it's because warm air trapped between the widely spaced front and rear doublets can't escape, or may be the lenses are just not up to the job. My NP101IS suffered from that problem and so does my vintage SDF, but on wide fields they are glorious.

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41 minutes ago, johninderby said:

You only have to see the flood of visual doublets hitting the market now to show how out of touch that statement is about there being no market for them.

Dare I raise the subject of TV undercits. 😁

Also in my opinion the answer of Al Nagler was incredible. But that was exactly what he said.

Again, I think that TV is now focusing only on eyepieces and imagers. For visual purists there is only Takahashi IMO. AP and TEC are too expensive and with too long waiting lists, TAK FC series is instead affordable.

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5 minutes ago, mikeDnight said:

I do think there would be a significant following who would buy Televue if they were available.

Yes, I would be one of them. But only in case of some "fresh projects", something new. TV prices are, at least here in Europe, terribly high. But if they were a little more innovative and, let me say, "courageous", I should be there...

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15 minutes ago, 883 said:

For visual purists there is only Takahashi IMO. AP and TEC are too expensive and with too long waiting lists, TAK FC series is instead affordable.

I think Vixen still offer some pretty top end Japanese ED's as their high end scopes,  but I do think that Takahashi set the standard that others try to emulate. Some more successfully than others. 

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