30 replies to this topic

[quilty]

on the fair I found this one:

Unique twin frac Vixen "Neoachromat" 120 f/6.7 on a selfmade mount tripod two 82° 30 mm eyepieces and wooden case for 1.300€

Isn't this a must buy? What pow wow can do the fracs before loosing contrast?

[mazdak]

Vixen NA120 uses Petzval design which reduces CA and Field Curvature. Better than simple achromatic refractor but shows chromatic aberration. Definitely a winner buy

[Martinbruce]

Here is a listing of one for sale: https://www.cameraco...fractor-op.html

 

The tag implies a 102 but if you go to the site you will see that it is a 120. They are very nice and for both wow. Cheers

[quilty]

Petzval, isn't that 4 elements?


The machining is great




Though it displays double stars like % :-)

Edited by quilty, 10 May 2025 - 12:36 PM.

[quilty]

I found more about Petzval scopes.

It seems they are 4 elements and specially for ap due to a large flat field while on axis they might be inferior to good triplets or even doublets at CA.

4 elements cooling down, isn't that an issue, too.

Thus from my armchair theorism sitting point of view, these NA 120 S are not the first choice for visual, am I right with that?

Edited by quilty, 12 May 2025 - 02:50 AM.

[CHASLX200]

Mine was good.

[Scott99]

What the heck?   A top-bottom mounted binoscope?  Never seen that before - it's one of a kind!  points for creativity there. 

[quilty]

That's not unusual. Avoids double prisms. Necessary when the tube diameter is larger than the eye distance, which is quite normal at 4" and larger

[quilty]

Mine was good.

Nevertheless you let go

[CHASLX200]

Nevertheless you let go

I let all stuff go for the next

[quilty]

Mentally, I've got it already.
Think I'll go for it. The rig is so well built that the frac choice might have been as thoughtful.

I don't know if the Vixen NA 120s have some Petzval element at the tube end or somewhere in the middle.

Tough I'm drowning in scopes. I got two eyes only, busy with this one then. What about the other scopes?

That's a nasty downside of this hobby, me want me want..

Edited by quilty, 12 May 2025 - 08:37 AM.

[Terra Nova]

With them offset like that, how do both eyepieces reach focus at the same point? Does one have a relay lens? BTW, I had the NA120 and also the 120S. Both were F6.67 Petzvals but the 120S was made in more limited numbers mainly for Japanese consumers and it was by far the better of the two. It had a triplet Petzval unit.

[quilty]

This one is labelled NA120S. Which one of both is it?



The lightpath in both is the same, just the diagonal prism position in the lightpath differs. The bottom tube is set back extra to compensate its longer lightpath past prism

Stephan

PS Today I made an astronomic chair already. This one seeks it. Until now I got away splendid without such stuff with my short cats.

Edited by quilty, 12 May 2025 - 03:54 PM.

[Terra Nova]

Just 120S. Here:

 

https://www.cloudyni...ents/?p=9793764

Edited by Terra Nova, 12 May 2025 - 05:25 PM.

[quilty]

So uncertain still what kind of fracs I'm about to purchase. If it was a double TSA 120 the price was ten times as much

[Kitfox]

So uncertain still what kind of fracs I'm about to purchase. If it was a double TSA 120 the price was ten times as much

 

Not to worry, if you hate it, I'm sure it could find a home in Kitfox Acres Observatory.  As a Vixen (female fox after all!), she will be happy here.  Alas, I am sure the line has already formed HOPING you despise it!!!  Which I think is highly unlikely!  

[quilty]

Vixen is a female fox? Always sth new to learn in here

My AC (astronomic chair) which I made yesterday

Edited by quilty, 13 May 2025 - 12:13 PM.

[Kitfox]

Are you picking it up at the fair?  When?  I am very interested in more photos and hearing how it performs!

[quilty]

Saw it there couldn't decide but think I'm purchasing it. About 200 miles away now. Want to see through it before.
The package is really great, hope the bitches will properly do. When positive worth the travel anyway

Well, one thing I already know. eye distance cannot properly be altered. (It's possible but you wouldn't do that just for a peep). Quite a downside, plus is only one prism in the lightpath, quite a lot of glass in there already
Seems to fit for me.

Doublebitch in a single trap

Edited by quilty, 14 May 2025 - 12:56 AM.

[quilty]

allow me to share my looking forward to. Coming in June, hope so.



I'm not sure if it isn't better at moment this way. Feltwise they're mine already but they don't stand in the way and neither push me to staying out of doors all night long :-)
And I didn't pay anything yet.

Like at ****. The most powerful device at this is our brain

Edited by quilty, 16 May 2025 - 02:39 AM.

[Kitfox]

Looks like you may be able to slide one of the scopes forward or back, which would effectively increase the ipd (though the eyepieces would be at an angle), but decreasing it wouldn’t be so simple. 
 

Come to think of it, most people find a binoviewer to be more comfortable angled a bit…

Edited by Kitfox, 16 May 2025 - 03:06 PM.

[Astrojensen]

I saw it, too, at the ATT and was quite surprised by how good the color correction was (it was set up so you could look at some branches on nearby trees). There was very little blue fringing. 

 

 

Clear skies!

Thomas, Denmark

[scout]

The package is really great, hope the bitches will properly do. When positive worth the travel anyway
Doublebitch in a single trap

I think your English auto-translator is malfunctioning.

[quilty]

I saw it, too, at the ATT and was quite surprised by how good the color correction was (it was set up so you could look at some branches on nearby trees). There was very little blue fringing. 
 
 
Clear skies!
Thomas, Denmark

Why didn't you tell? We could have met. I think it was about 30 mm eyepieces so at like 25x pow wow.
I wouldn't expect any CA at such pow. I'd like to know at what pow it really starts loosing contrast.

And true, it seems there are no advantages of two separated scopes vs. splitted binoviewers except less glass in the light path

to scout: I never use the poor auto translator. Vixen is a **** isn't she? (Ok, I checked the dictionary right after Kitfoxes tip)

Thomas, did you see the complete forked forked Meade 8 ACF for 450, too? Was hard to me to let it go. Would have been my best value/money purchase ever.

Stephan

PS: That silly autocorrector takes a doublebitch but no single ****That must be the reason for the brandname Vixen :-)

PS2: I found this Janusdog Attention! Product Placement. But it rather stands for a binoviewer than for a binoscope. Or more rather a binacustic (great anyway) sensation

Edited by quilty, 17 May 2025 - 02:58 AM.

[quilty]

Looks like you may be able to slide one of the scopes forward or back, which would effectively increase the ipd (though the eyepieces would be at an angle), but decreasing it wouldn’t be so simple. 
 
Come to think of it, most people find a binoviewer to be more comfortable angled a bit…

Are you talking me out of it? Would you say it's looking great and special by the look at it but less so by the look through it?

Well, I think as you do, it's possible to increase eye distance but I'd adjust once for me and not for the public.
As displayed it did to me with the eyepieces equipped with. And I do have quite a narrow ed.
Cmon, feel free. Still I'm open to any cons, not too late yet.