49 replies to this topic

[mikeDnight]

I presently own a TeleVue SDF refractor.

I have the opportunity to upgrade to a TeleVue 101.

 

I am very satisfied with the views through the SDF.

Is it worth the upgrade to the TV101 or wait for a NP101 (which would be more expensive) ?

What is it about the NP101 IS that leads you to believe it's an upgrade? Personally I prefered my SDF over my NP101 IS. Each to their own however, but I'm not sure I'd consider it an "upgrade", as the SDF is already a gorgeous RFT. The NP101 has little to offer beyond what you already have. It's a very nice rich field scope but it lacks definition and doesn't take magnification well. It's also fearsomly expensive for what it is, and there are far better kids on the block than TeleVue as far as refractors go. If you want better performance on the Moon & planets, better definition and high power potential, then I'd suggest the Tak FC100DZ or any of its siblings. 

[Spikey131]

What is it about the NP101 IS that leads you to believe it's an upgrade? Personally I prefered my SDF over my NP101 IS. Each to their own however, but I'm not sure I'd consider it an "upgrade", as the SDF is already a gorgeous RFT. The NP101 has little to offer beyond what you already have. It's a very nice rich field scope but it lacks definition and doesn't take magnification well. It's also fearsomly expensive for what it is, and there are far better kids on the block than TeleVue as far as refractors go. If you want better performance on the Moon & planets, better definition and high power potential, then I'd suggest the Tak FC100DZ or any of its siblings. 

I am sorry that your NP101 “doesn’t take magnification well”.  Mine does, and for solar system observing, I am generally limited by seeing, not magnification.  And for double stars, I have been able to push the magnification to 540x without image breakdown.

[Jon Isaacs]

What is it about the NP101 IS that leads you to believe it's an upgrade? Personally I prefered my SDF over my NP101 IS. Each to their own however, but I'm not sure I'd consider it an "upgrade", as the SDF is already a gorgeous RFT. The NP101 has little to offer beyond what you already have. It's a very nice rich field scope but it lacks definition and doesn't take magnification well. It's also fearsomly expensive for what it is, and there are far better kids on the block than TeleVue as far as refractors go. If you want better performance on the Moon & planets, better definition and high power potential, then I'd suggest the Tak FC100DZ or any of its siblings. 

 

What Company 7 says:

 

"The first TeleVue 4" Apo that we rate as the equal of the worlds best in optics and mechanics!"

 

I use my NP-101 at 300x on the planets and double stars. 

 

Mr. Yoshida and his group ranked the NP-101 near the top of 4 inch refractors as a planetary scope, the same score as the TSA102... Notice where the Genesis SDF is ranked... 

 

(69 points）Zeiss APQ100/1000
(68 points）William Optics10cmF8
(67 points) TV NP101
(67 points）Takahashi TSA-102
(66 points）Zeiss APQ100/640
(66 points）TAKAHASH FSQ-106ED
(66 points）NIKON 10cmED
(66 points）William Optics FLT110
(65 points) Vixen FL102
(65 points）Takahashi FSQ-106
(64 points) TV TV101
(63 points) TV TV102
(63 points）Takahashi FS-102
(63 points）PENTAX 105SD
(62 points）UO　WHITEY DOB 15cmF8
(61 points) TV SDF

 

Jon

[GGK]

Just an update:

 

With Trump’s tariffs and Canada’s 25% tariff retaliation, $CDN to $US at nearly 45%, shipping, basic import GST purchasing any astronomy items from the USA is extremely prohibitive. Have to look for Canadian opportunities.

 

More CN input would be appreciated concerning the following 2 options (again only visual) from my existing TV SDF for basically the same price:

Both are available for in person pickup within reasonable driving distances, so no issues with possible mis-collimation due to shipping.

 

1. TeleVue TV101 OTA (single rate focuser) with case/TV 2” Everbrite star diagonal + Gibraltar mount 

or 

2. TeleVue NP101 (single rate focuser) with case only

I am leaning to option 1 for the following reasons:

I don’t need the 2” Everbrite star diagonal or the Gibraltar mount.

Both can be sold to reduce the cost of purchase of TV101.

 

Do a shootout between the TV 101 and my current TV SDF.

(My current SDF easily does 200X without breaking a sweat).

The TV101 should be the better scope optically.

 

Any thoughts or input would be appreciated.

 

Thx,

Gary 
 

I'd by the NP101 simply because it's 4" shorter than the TV102, and I like convenience.

 

But, why do you want a Petzval refractor at all?  You're talking about high power in the posts above, and you already have a Tak FS102.

 

I use Petzval refractors for wide field / rich field observing, and I want to see as much low power detail and faint stars as possible and I want to be able to detect faint DSOs even at the edge of the wide field.  Increasing contrast by removing CA and field curvature makes more things visible at low power - especially in a quality scope that minimizes light scatter. That's why I use a Petzval APO.  I purchased the "is" version of the NP101 for visual even though it's mainly an imaging scope just to be sure I have the largest fully illuminated field possible at the widest views. 

 

I've never looked through the SDF, but what I read says that there is a noticeable difference between the SDF and the NP regarding chromatic aberration, and that the TV102 is somewhere between.  So, what is your opinion of "good enough"?  If your main use is high power with only a casual and occasional wide-field use, then I believe you've already answered your own question with your compliments about your SDF.

 

Have fun either way, because both would be fun to compare to your other scopes.

 

Gary

Edited by GGK, 20 March 2025 - 09:07 PM.

[gabeeg]

I have gone through this thought process more than once as an owner of a Genesis SDF myself (my primary scope).  I started with an original Genesis (non-SDF) and upgraded to a used mint SDF after a few years, once the NP101 came out I planned on jumping to a 101 as I figured some would start showing up on the used market...but I didn't, I just did not feel the need to.  Reports indicated that in terms of sharpness, usability features there was not much reason and I was satisfied with the SDF.   The next plan was to jump to a NP101 after a few years, but instead I installed a Feathertouch dual speed focus adapter on the my SDF and I was satisfied.   The one thing that seems I am missing vs. the NP is photographic performance and less chromatic aberration ...but I am visual only and I am seldom spending much of any time viewing Vega, Sirius, etc. so I am never affected by spurious color (I do view planets...but if there is spurious color I do not much notice it).   I am sure if I had my SDF next to a NP101 and compared the two side by side I might see some contrast improvement...maybe I could eek out a barely noticeable detail or two on Mars or Jupiter on nights of great seeing....but I probably will never have this side by side experience and I'm not sure it is worth the cost (for some it might be!) as a purely visual person.   Not sure if this helps at all and I guess what I am getting at is IMO if you have the urge to make a jump and actually want to see a noticeable difference, get more aperture (or if you are into high mag., a longer focal length scope).   ...now if you were planning on getting into astrophotography, my opinion would be different...the NP101 would probably be a substantial jump.

[Mike W]

I'd by the NP101 simply because it's 4" shorter than the TV102, and I like convenience.

 

But, why do you want a Petzval refractor at all?  You're talking about high power in the posts above, and you already have a Tak FS102.

 

I use Petzval refractors for wide field / rich field observing, and I want to see as much low power detail and faint stars as possible and I want to be able to detect faint DSOs even at the edge of the wide field.  Increasing contrast by removing CA and field curvature makes more things visible at low power - especially in a quality scope that minimizes light scatter. That's why I use a Petzval APO.  I purchased the "is" version of the NP101 for visual even though it's mainly an imaging scope just to be sure I have the largest fully illuminated field possible at the widest views. 

 

I've never looked through the SDF, but what I read says that there is a noticeable difference between the SDF and the NP regarding chromatic aberration, and that the TV102 is somewhere between.  So, what is your opinion of "good enough"?  If your main use is high power with only a casual and occasional wide-field use, then I believe you've already answered your own question with your compliments about your SDF.

 

Have fun either way, because both would be fun to compare to your other scopes.

 

Gary

NEVER saw ANY C/A in my TV102. My Genesis-yes, my Ranger-yes, my SDF -maybe, don't remember so it can't be much.

[vkhastro1]

   I am sure if I had my SDF next to a NP101 and compared the two side by side I might see some contrast improvement...maybe I could eek out a barely noticeable detail or two on Mars or Jupiter on nights of great seeing....but I probably will never have this side by side experience and I'm not sure it is worth the cost (for some it might be!) as a purely visual person.   Not sure if this helps at all and I guess what I am getting at is IMO if you have the urge to make a jump and actually want to see a noticeable difference, get more aperture (or if you are into high mag., a longer focal length scope).   ...now if you were planning on getting into astrophotography, my opinion would be different...the NP101 would probably be a substantial jump.

Great point with respect to visual.

I have no  inclination to get back into astro-photography - been there/done it.

100 % visual !!

[dawnpatrol]

As a Genesis SDF owner/user who is exclusively visual with the Genesis SDF, I've never felt a need to move to a TV-101. I've never compared the scopes next to one another, but when I look through the SDF, I never feel that creeping sense of doubt that I've had with other scopes. I use premium eyepieces with the SDF and I spend more time with it at lower power than high magnification and it simply never disappoints. If you have the itch to trade up to a TV-101, by all means, scratch it. I'm sure you won't be disappointed, but IMHO, any improvements will be very slight if at all. The Genesis SDF is just really, really good for visual. 

[Jon Isaacs]

 

The one thing that seems I am missing vs. the NP is photographic performance and less chromatic aberration ...but I am visual only and I am seldom spending much of any time viewing Vega, Sirius, etc. so I am never affected by spurious color (I do view planets...but if there is spurious color I do not much notice it).   I am sure if I had my SDF next to a NP101 and compared the two side by side I might see some contrast improvement...maybe I could eek out a barely noticeable detail or two on Mars or Jupiter on nights of great seeing....

 

l'm 100% visual.   For planetary, it is not the chromatic aberration you see that matters, it's chromatic defocus you don't see that affects the contrast and sharpness.  I have casually looked through a few SDFs, never made side by side comparison with my NP-101. 

 

If you had your SDF next to an NP-101, I think you just might be surprised at what you see.  

 

Jon

[RichA]

What Company 7 says:

 

"The first TeleVue 4" Apo that we rate as the equal of the worlds best in optics and mechanics!"

 

I use my NP-101 at 300x on the planets and double stars. 

 

Mr. Yoshida and his group ranked the NP-101 near the top of 4 inch refractors as a planetary scope, the same score as the TSA102... Notice where the Genesis SDF is ranked... 

 

(69 points）Zeiss APQ100/1000
(68 points）William Optics10cmF8
(67 points) TV NP101
(67 points）Takahashi TSA-102
(66 points）Zeiss APQ100/640
(66 points）TAKAHASH FSQ-106ED
(66 points）NIKON 10cmED
(66 points）William Optics FLT110
(65 points) Vixen FL102
(65 points）Takahashi FSQ-106
(64 points) TV TV101
(63 points) TV TV102
(63 points）Takahashi FS-102
(63 points）PENTAX 105SD
(62 points）UO　WHITEY DOB 15cmF8
(61 points) TV SDF

 

Jon

I'd say the ratings between the 101, SDF and Tak FS102 are accurate, based on what I saw, however, it is arbitrary.

[RichA]

NEVER saw ANY C/A in my TV102. My Genesis-yes, my Ranger-yes, my SDF -maybe, don't remember so it can't be much.

 

Agree.  I had one and a SW120 at the same time, the 102 was the better scope.

[mikeDnight]

What Company 7 says:

 

"The first TeleVue 4" Apo that we rate as the equal of the worlds best in optics and mechanics!"

 

I use my NP-101 at 300x on the planets and double stars. 

 

Mr. Yoshida and his group ranked the NP-101 near the top of 4 inch refractors as a planetary scope, the same score as the TSA102... Notice where the Genesis SDF is ranked... 

 

(69 points）Zeiss APQ100/1000
(68 points）William Optics10cmF8
(67 points) TV NP101
(67 points）Takahashi TSA-102
(66 points）Zeiss APQ100/640
(66 points）TAKAHASH FSQ-106ED
(66 points）NIKON 10cmED
(66 points）William Optics FLT110
(65 points) Vixen FL102
(65 points）Takahashi FSQ-106
(64 points) TV TV101
(63 points) TV TV102
(63 points）Takahashi FS-102
(63 points）PENTAX 105SD
(62 points）UO　WHITEY DOB 15cmF8
(61 points) TV SDF

 

Jon

 I apologise for being controversial but I believe the above to be a case of The Kings New Clothes. Even Televue acknowledge their 102 is a better planetary scope than their NP101, so I've no idea where company 7 magic their opinion from. I bought a brand new NP101IS back in 2008 and observed with on practically every clear night, often alongside other apo and ED refractors.  Saturn was high and the difference between my 101 and my friends Vixen 102 EDSS F6.5 was mindblowing. The 101 never matched the ED doublet as a planetary scope. The difference between the two in terms of definition was vast, with the Vixen ED slaughtering the NP101 everytime. It was embarrassing,  as 101 coudn't even compete on the level with the Vixen ED when observing the Moon. The NP101 was awesome as an RFT but its ability ended there; as a planetary scope it was definitely the poor cousin.

 

 Mr Yoshida and his group must have suffered a mass seizure or something during their ranking of those refractors, as no NP101 could ever match a TSA 102 or FS102 as a planetary scope unless the seeing was compromised somehow. The sad thing is that people believe such nonsense, when in reality it's pure Alice In Wonderland! 

Edited by mikeDnight, 21 March 2025 - 05:57 PM.

[GGK]

Mind blowing, vast, slaughtering, embarrassing - it sounds like that NP101 was out of collimation.

[Jon Isaacs]

 

Mr Yoshida and his group must have suffered a mass seizure or something during their ranking of those refractors, as no NP101 could ever match a TSA 102 or FS102 as a planetary scope unless the seeing was compromised somehow. The sad thing is that people believe such nonsense, when in reality it's pure Alice In Wonderland!

 

And you expect me to believe who?

 

Jon

[PKDfan]

I apologise for being controversial but I believe the above to be a case of The Kings New Clothes. Even Televue acknowledge their 102 is a better planetary scope than their NP101, so I've no idea where company 7 magic their opinion from. I bought a brand new NP101IS back in 2008 and observed with on practically every clear night, often alongside other apo and ED refractors. Saturn was high and the difference between my 101 and my friends Vixen 102 EDSS F6.5 was mindblowing. The 101 never matched the ED doublet as a planetary scope. The difference between the two in terms of definition was vast, with the Vixen ED slaughtering the NP101 everytime. It was embarrassing, as 101 coudn't even compete on the level with the Vixen ED when observing the Moon. The NP101 was awesome as an RFT but its ability ended there; as a planetary scope it was definitely the poor cousin.

Mr Yoshida and his group must have suffered a mass seizure or something during their ranking of those refractors, as no NP101 could ever match a TSA 102 or FS102 as a planetary scope unless the seeing was compromised somehow. The sad thing is that people believe such nonsense, when in reality it's pure Alice In Wonderland!

Lol EXACTLY Mike !!!

Its makes ZERO sense but since you waded in Mr. Yoshida is indeed Blind lol.


CSS
Lance

[25585]

 I apologise for being controversial but I believe the above to be a case of The Kings New Clothes. Even Televue acknowledge their 102 is a better planetary scope than their NP101, so I've no idea where company 7 magic their opinion from. I bought a brand new NP101IS back in 2008 and observed with on practically every clear night, often alongside other apo and ED refractors.  Saturn was high and the difference between my 101 and my friends Vixen 102 EDSS F6.5 was mindblowing. The 101 never matched the ED doublet as a planetary scope. The difference between the two in terms of definition was vast, with the Vixen ED slaughtering the NP101 everytime. It was embarrassing,  as 101 coudn't even compete on the level with the Vixen ED when observing the Moon. The NP101 was awesome as an RFT but its ability ended there; as a planetary scope it was definitely the poor cousin.

 

 Mr Yoshida and his group must have suffered a mass seizure or something during their ranking of those refractors, as no NP101 could ever match a TSA 102 or FS102 as a planetary scope unless the seeing was compromised somehow. The sad thing is that people believe such nonsense, when in reality it's pure Alice In Wonderland! 

The FSQ-106 and Vixen FL-102 I imagine would be up top too. That list is outdated anyway, snd is only one individual's ratings, its not gospel.

 

A more contemporary list:

 

FC100DZ, DL, DF

APM LZOS 115

Vixen SD100

FSQ-106 (latest)

TV NP101

CFF 102 F10

Altair Planeta F11

SW 100 ED

APM LZOS 100 F8

Vixen AX103

[Chen Sir]

but I've heard the TV101 is color-free. 

Is TV101 really color-free?

 

I have been observing Jupiter with my NP101 since last year, and I can perceive some blue and yellow hue on the rim of the globe at the opposite direction, using eyepieces such as TV NZ 3-6, Pentax XO2.5 and ZAO 4mm.

 

Does anyone have the same experience?

Edited by Chen Sir, 21 March 2025 - 09:34 PM.

[RichA]

Mind blowing, vast, slaughtering, embarrassing - it sounds like that NP101 was out of collimation.

Which may not be uncommon for those pseudo-Petzval type scopes.  I've seen a few tested that had collimation issues.  It's a pretty tall order, keeping the centre element perfectly parallel with the objective and the focuser.

[RichA]

Is TV101 really color-free?

 

I have been observing Jupiter with my NP101 since last year, and I can perceive some blue and yellow hue on the rim of the globe at the opposite direction, using eyepieces such as TV NZ 3-6, Pentax XO2.5 and ZAO 4mm.

 

Does anyone have the same experience?

Can be one of two things:  Atmospheric dispersion because the object is less than 45 degrees above the horizon, or, slighht lateral displacement of one element relative to the other.

[Chen Sir]

 slighht lateral displacement of one element relative to the other.

Can't understand. Dose that mean there is something wrong with my lenses?

[Jon Isaacs]

The FSQ-106 and Vixen FL-102 I imagine would be up top too. That list is outdated anyway, snd is only one individual's ratings, its not gospel.

 

A more contemporary list:

 

FC100DZ, DL, DF

APM LZOS 115

Vixen SD100

FSQ-106 (latest)

TV NP101

CFF 102 F10

Altair Planeta F11

SW 100 ED

APM LZOS 100 F8

Vixen AX103

 

Actually, it was a group of indivisuals who were dedicated planetary observers in Japan.  

 

The point here though is that the SDF was not highly rated whereas the NP-101 was.

 

Jon

[mikeDnight]

Mind blowing, vast, slaughtering, embarrassing - it sounds like that NP101 was out of collimation.

 No, it was perfectly collimated! It just ran out of steam when magnification was demanded of it. I sent it back to the vendor, but it was returned to me with the assurance that there was nothing wrong and it was in perfect condition. Both scopes, the 101 and the Vixen 102 EDSS used Nagler eyepieces and TV diagonals, so were on an equal footing eyepiece wise. The only difference was that I needed to use a powermate to keep up with the Vixens magnification which shouldn't have had any detrimental effect on the final image. I'll be honest, it really disappointed me as I really wanted the NP101 to be The Perfect 4" scope. It was Saturn's rings that was the real clincher for me. In the 101 Cassini's division and the differences between A & B rings were easy to see, but in the Vixen the Enke minima in the A ring was observable with ease, Cassini's division showed a softer outer edge against the A ring and sharp inner edge agajnst the B ring. The B ring in the Vixen was a mass of fine divisions barely perceived but still obvious, while the 101 showed a blank ring. The Crepe ring was obvious in the Vixen but not seen in the 101. There was such a difference visually that it was obvious to all who used the scopes. It's sad and has left me with a bad taste in my mouth 're the TVNP101, not to mention the extreme high price I paid for my disappointment. 

[GGK]

 No, it was perfectly collimated! It just ran out of steam when magnification was demanded of it. I sent it back to the vendor, but it was returned to me with the assurance that there was nothing wrong and it was in perfect condition. Both scopes, the 101 and the Vixen 102 EDSS used Nagler eyepieces and TV diagonals, so were on an equal footing eyepiece wise. The only difference was that I needed to use a powermate to keep up with the Vixens magnification which shouldn't have had any detrimental effect on the final image. I'll be honest, it really disappointed me as I really wanted the NP101 to be The Perfect 4" scope. It was Saturn's rings that was the real clincher for me. In the 101 Cassini's division and the differences between A & B rings were easy to see, but in the Vixen the Enke minima in the A ring was observable with ease, Cassini's division showed a softer outer edge against the A ring and sharp inner edge agajnst the B ring. The B ring in the Vixen was a mass of fine divisions barely perceived but still obvious, while the 101 showed a blank ring. The Crepe ring was obvious in the Vixen but not seen in the 101. There was such a difference visually that it was obvious to all who used the scopes. It's sad and has left me with a bad taste in my mouth 're the TVNP101, not to mention the extreme high price I paid for my disappointment. 

Thanks for the details.  Fair enough, then.  Your original descriptive words made it sound to me like you could see detail in Mars in one scope and basically couldn't find mars in the other, so it lacked any credibility and made me guess that you had no idea what you were doing. That's why I made my first reply.

 

Gary

[sw196060]

Different opinions based on different experiences. 
Not sure who to believe.  Likely all valid. Could be unit-to-unit variation. 

[Wildetelescope]

 I apologise for being controversial but I believe the above to be a case of The Kings New Clothes. Even Televue acknowledge their 102 is a better planetary scope than their NP101, so I've no idea where company 7 magic their opinion from. I bought a brand new NP101IS back in 2008 and observed with on practically every clear night, often alongside other apo and ED refractors.  Saturn was high and the difference between my 101 and my friends Vixen 102 EDSS F6.5 was mindblowing. The 101 never matched the ED doublet as a planetary scope. The difference between the two in terms of definition was vast, with the Vixen ED slaughtering the NP101 everytime. It was embarrassing,  as 101 coudn't even compete on the level with the Vixen ED when observing the Moon. The NP101 was awesome as an RFT but its ability ended there; as a planetary scope it was definitely the poor cousin.

 

 Mr Yoshida and his group must have suffered a mass seizure or something during their ranking of those refractors, as no NP101 could ever match a TSA 102 or FS102 as a planetary scope unless the seeing was compromised somehow. The sad thing is that people believe such nonsense, when in reality it's pure Alice In Wonderland! 

Hi Mike!  Lol.  Marty at Company 7 is one of the most picky and fastidious people I have ever met when it comes to optics, to the point of it turning off potential customers and greatly irritating manufacturers that he returns scopes that do not meet his standards.  Everything written on his website is based on his own experience with the gear.   I have a TV102 which I have talked about and it is truly an excellent planetary scope, for a 4 inch scope.  My version is certainly competitive with my TMB and Sky90 optics for sure.  However I have look through different versions of the 101 design and I know many folks that have them.  My own experience and those of the folks i know is that it is also an excellent planetary scope with the right eyepieces and extenders.  I do NOT doubt your experience, but I would guess there was SOMETHING off with your sample.  It happens.  In my experience a well collimated TV Petzval with quality extenders like the powermates should give you pretty much all of what you should get from a 4 inch refractor.   As far as the relative comparisons between scopes and Mr. Yoshita’s list,  my first question would be what is the real difference between a 63 and a 67 rating(think I got those right) at the eyepiece?   The relative comparisons are often helpful, but context helps with understanding the significance of the ranking. 

 

JMD