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Vixen NA140SSf Neo Achromatic - Any Experience/Comments?

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#1 TMSP

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Posted 17 August 2014 - 12:57 PM

The ads and price look interesting. 5.5", 4 element, 2 speed focuser for $2K. Vixen quality? Is this too good to be true? Anyone with experience with this new scope?

 

Thanks for any comments



#2 terraclarke

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Posted 17 August 2014 - 01:11 PM

There have been a lot of posts on this particular telescope in the refractors forum. It is a current model and typically can be purchased brand new for this price. Also, it is not an apo even though its a Petzval design, so there is color, though it is comparable to a standard Franhofer achromat of the same diameter and twice the focal length. I suggest you check out the refractors forum.



#3 TMSP

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Posted 17 August 2014 - 04:03 PM

Thanks Terra. Yup, lot's there. Missed that forum with the new layout, but I stopped looking too soon! Regards,



#4 actionhac

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Posted 17 August 2014 - 06:55 PM

I owned a 120mm F6.7 version and thought it had too much false color. It may have had advantages for photography like a flat field with this  4-element in 2-groups Petzval design but for visual I could not live with all the color. Everyone has a different tolerance to CA. I still have pictures in my file. Mine was a older model with Great Polaris mounting.

Attached Files



#5 bremms

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Posted 17 August 2014 - 07:06 PM

It's a F12 -F13  with a focal reducer. The petzval lens doesn't seem to add any correction. It's longer than an F7 ED and has more color. Looked through one and was underwhelmed. My D&G 5" F12 was a better scope by a good bit. The OTA was lighter too.



#6 terraclarke

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Posted 17 August 2014 - 08:24 PM

I too had an NA120 (120mm x 800mm) and it had the worst color (CA) of any achromat that I have ever owned. Far worse than my ST120! And that is weird. The limb of the moon was a raging sea of purple. I sold it and got a Vixen 4" F9 Fluorite. A quantum leap in performance even though it was 20mm less aperture.



#7 actionhac

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Posted 17 August 2014 - 08:52 PM

When you  observe with classics you do not have much tolerance for CA, it seems to be a modern problem. There is no getting around the laws of physics.

I will say though I find D&G's 6 inch f12 perfectly fine. I don't know how Barry does it.


Edited by actionhac, 17 August 2014 - 09:21 PM.


#8 bremms

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Posted 17 August 2014 - 09:22 PM

I have tolerance for CA. One of my main scopes is a 6" F10 Achromat. The Vixen Neo achros are just not very good. Love the people with the ES ar152.." It has almost no CA" ARE YOU BLIND?



#9 terraclarke

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Posted 18 August 2014 - 07:18 AM

I love my 6" F5 refractor but I only use it for DSOs from dark sites. I've never tried to use it for what it wasn't intended for. You don't use a shotgun to bring down a deer when you have a 30.06, and you sure don't use the 30.06 on quail! For everything there is a purpose and there are very few things that accomplish many purposes and do them all well.



#10 actionhac

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Posted 18 August 2014 - 11:34 AM

Sometimes gobs of CA can be fun.

Kinda like BurgerKing tacos, they are so bad they are actually quite good. Especially when smothered in their extra hot sauce (don't get this stuff in your eyes like I did).

I owned a unknown  5"f5 with a  objective made out of glass and plastic cell. The moon itself showed very little false color, but it had this fantastic bright neon hot pink purple fringe wave about a mile high that appeared to be moving across the surface, like someone had just detonated a genesis device. Thats the best way I can describe it, it was really something.

 

Robert



#11 starman876

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Posted 19 August 2014 - 06:56 AM

all intersting comments about this scope. I wonder if they are all the same.  The one I had was very good and I did not see the horrible CA that everyone stated this scope shows.  The views of Jupiter and the moon very good.  I must admit though, the 120 version I have is sharper on the planets.  



#12 Jim Curry

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Posted 19 August 2014 - 10:48 AM

all intersting comments about this scope. I wonder if they are all the same.  The one I had was very good and I did not see the horrible CA that everyone stated this scope shows.  The views of Jupiter and the moon very good.  I must admit though, the 120 version I have is sharper on the planets.  

Me too.  No issues until high magnifications.  Dave Russell has one and proposes a Longpass filter to address this.  I've seen Jupiter well over 250x that looked like calligraphy (no filters) it was so well resolved.  I have the Japanese version, don't know if that's different than newer ones.

 

Jim



#13 starman876

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Posted 19 August 2014 - 01:18 PM

 

all intersting comments about this scope. I wonder if they are all the same.  The one I had was very good and I did not see the horrible CA that everyone stated this scope shows.  The views of Jupiter and the moon very good.  I must admit though, the 120 version I have is sharper on the planets.  

Me too.  No issues until high magnifications.  Dave Russell has one and proposes a Longpass filter to address this.  I've seen Jupiter well over 250x that looked like calligraphy (no filters) it was so well resolved.  I have the Japanese version, don't know if that's different than newer ones.

 

Jim

 

That is what I was wondering. Are people talking about the old version of the NA scopes or the newer version.   I had a 140 that was the newer version and I did not see any horible CA.  The 120 I still have is an older version and it has no CA at all.  Maybe ny eyes just are not sensitive to the blue region.  



#14 terraclarke

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Posted 19 August 2014 - 02:15 PM

Mine was the old version NA120. Made in Japan. Got it with a GPDX. Both had the mint greenish gold trim. It was a very cool looking scope. Just like Robert's in the picture. I will try and find an old photo of it. I purchased it in April of 2001.  But it had the worst CA of any scope I have ever owned and I am fairly tolerant of CA. I currently have an ST120 and an OmniXLT150R F5 refractor. And let me tell you, I like the 120 and the 150, they are keepers to me. But my NA120 was a dog! It had horrible CA! Way worse than the 120 and 150 F5s! Maybe it was a lemon? I was happy to get rid of it. 



#15 CHASLX200

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Posted 19 August 2014 - 05:29 PM

I had one years back. Not sure what size it was, i know it was over 4".  It did pretty good all around.

 

Chas



#16 Bomber Bob

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Posted 19 August 2014 - 05:43 PM

Hate to hear about the so-so performance from a Vixen product.  I seriously looked at them in the Orion catalog back when I was trying to decide about how large a refractor I could transport.  Sounds like I dodged a bullet.



#17 actionhac

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Posted 19 August 2014 - 06:04 PM

Mine was the early version 120mm like Terra's. My photo is in this thread back a few posts. I bought mine without even looking through it having complete faith in Vixen quality. I was sorry almost immediately, even during the daytime tree branches are fringed in purple. 

I have zero tolerance to CA. I will not tolerate any of that nonsense. I won't have purple smeared all over mother natures beauty. 

There are plenty of telescopes with CA under control, at least you  see very little of it visually. Its there even in the best classic f15 achromats, but it is not noticed with your eye, it is still there doing damage to the resolution and contrast.

Ed Ting reviewed the same one I owned:

http://www.scoperevi...m/page1j.html#7

 

Robert


Edited by actionhac, 19 August 2014 - 06:13 PM.

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#18 CHASLX200

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Posted 19 August 2014 - 06:45 PM

I think i had the 120mm version. I don't remember the color being that bad , but i i used it for deepsky more than i did the planets. I can stand a  little bit of color, but can't stand coma in a Newt.

 

Chas



#19 starman876

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Posted 20 August 2014 - 05:14 PM

So from all the above reports not all the NA series scopes were built to the same standards.   I wonder if the second set of elements were installed correctly.   The second set is also a achromat.  It is a very long focal length achromat.  It is like using a focal reducer which you can buy for any refractor.  You can actually remove it and have a longer focal length refractor.  I have not tried it, but I could on NA120 I still have. 



#20 Jim Curry

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Posted 20 August 2014 - 10:00 PM

When checking the alignment of my fleet last winter with my Cheshire, the V140NA was dead nuts accurate. Everything else required tiny tweaks, not this (thank goodness, there's no adjustment for the consumer).  I wonder if optics misalignment is the problem for folks.  I have trouble believing the variation in quality is due to glass.

 

Jim








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