44 replies to this topic

[LukaszLu]

I search the internet but to no avail. Maybe someone recognizes this construction?

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[Richard O'Neill]

I don't recognize it. Perhaps it's an early version from Unitron for a microscope?

[ngc7319_20]

I've seen it before on a scope.  Will try to recall...

[Garyth64]

Jason Rotary Power, I think.

[LukaszLu]

Jason Rotary Power, I think.

In this case, the optical axes of the eyepieces lie in the same plane as the axis of the telescope ...

[PawPaw]

Unitron offered one that was designed for their 700 series scopes in the 60's.  Not as common as their unihex.  

 

See Dave Trott's video:

 

https://www.youtube....h?v=PER__3A0Ne0

 

Don

[Terra Nova]

Unitron offered one that was designed for their 700 series scopes in the 60's.  Not as common as their unihex.  

 

See Dave Trott's video:

 

https://www.youtube....h?v=PER__3A0Ne0

 

Don

Yes, and I think they only work for straight-thru viewing. No mirror or prism inside.

[Kasmos]

Like Dave shows in the video, it was a stand alone model, not an accessory. What's curious is how closely the other brands were made and like them my Mayflower vari-power (Circle T) had the exact same tripod and mount. My guess is that all of them that had the 3 rotating EPs were the earliest versions of the var-power scopes, and were replaced by the ones that you pulled the draw tube to change powers.

[izar187]

With the built in image erector in the video, does that imply that the original concept market was perhaps terrestrial spotting scopes? Military concept cross-over?

[LukaszLu]

Unitron offered one that was designed for their 700 series scopes in the 60's.  Not as common as their unihex.  

 

See Dave Trott's video:

 

https://www.youtube....h?v=PER__3A0Ne0

 

Don

Yes! I think that's it! Thank you for all suggestions and help!!

[LukaszLu]

Well, it seems this is not an Unitron. Maybe the Hy-Score (Goto) Vari-Power? I've decided to buy it and will make some more photos when it arrives...

[Marty0750]

Eyepieces have that Unitron design look. The unit however is not Unitron

 

Unitron eyepieces from my collection

https://www.cloudyni...2#entry10756239

[dave brock]

I have one that looks like Unitron but no maker's mark. No image erector.

 

[LukaszLu]

I have one that looks like Unitron but no maker's mark. No image erector.

 

new pics 11.jpg

Hi, it looks like the "Rotary Eyepiece Selector" from Unitron/Polarex NS 133N-11 - it can be seen on Dave Trott's video mentioned by Don: https://youtu.be/PER__3A0Ne0?t=228

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[PawPaw]

To be technically correct......Nihon Seiko manufactured a rotary eyepiece unit similar to the pic in your first post that was offered by Unitron, Polarex, and other resellers/importers.

 

"I have one that looks like Unitron but no maker's mark. No image erector."

Dave that looks like Nihon Seiko to me, especially the slots in the eyepiece tubes.

 

Don

[LukaszLu]

When identifying, it is helpful to know what is removable and what is not. In some cases, eyepieces are removable, but the whole unit remains permanently attached to the focuser, in other cases the whole unit and the eyepieces are removable, and in others - everything is permanently attached.
It seems that in my case eyepieces are removable, while the whole unit is not.

[starman876]

Yes, only seen a few times.  I think one was for sale not to far from here.  Unitron all the way.

[LukaszLu]

OK, the eagle has landed... What do you think? Does anyone know this species?

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[starman876]

Nihon Seiko production on the eyepieces holder.   The T on the focuser looks like Towa.  

Edited by starman876, 22 January 2021 - 08:36 AM.

[LukaszLu]

Hi, the problem is that the eyepiece holder seems to be integral part of the scope. It's unremovable, as well as the eyepieces (they can be unscrewed). So NS eyepiece holder in a Towa's scope? Is it possible? Please note, that eyepieces magnifications differ from early Unitron/Polarex 133N and are the same as Hy-Score Vari-Power. Maybe this is a lead?

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[LukaszLu]

A few more pics - maybe someone will recognize something characteristic?

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[LukaszLu]

Although I do not have too much time because I spend most of it cleaning and regreasing the Kenko TA-910 refractor that has recently reached me, I also try to work on this unusual, intriguing specimen.

 

I cleaned the lens, tube and focuser. The lens seems to be in great, almost perfect condition (no fungus - what a relief!!!). It's probably glued as I can't see spacers or traces of dust etc. on the inner surfaces. I have never seen such an old lens that is not air spaced... Honestly, I've been looking at this lens for a long time, trying to make sure the second lens is even there. However, the focus is where it should be, so I rejected the hypothesis about the lack of a lens, despite rather poor images I got during the first tests.

 

A few words about design: The focal length is about 50 cm, and the focus is still inside the tube. Why? It turns out that the eyepiece revolver has not only image erector, but probably Barlow lens as well. It reaches the focal point inside the tube and allows to get relatively high magnification while keeping the scope dimensions compact, which in the case of such a marketing concept aimed at creating a universal and portable spotting scope seems to be the basic condition. Especially since the eyepiece holder significantly enlarges the dimensions...

 

All of this leads to a pile of problems that worsen image quality. The first is low aperture ratio (~F 8,3), which is a challenge even in the case of modern achros. Supplementary lenses probably don't improve this problem - quite the contrary. Their condition and correct setting must be checked. So next to the what is this? question, another key question arises: HOW TO DISASSEMBLE THIS REVOLVER...?

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Edited by LukaszLu, 27 January 2021 - 10:17 AM.

[Kasmos]

My opinion, Towa thru and thru and it's very likely the exact same scope shown in the Hy-Score ad. I believe it's been mentioned several times that unlike the others, which are Goto, the Hy-Score vari-power is a Towa.

 

Your experience so far is a good example of why I tell beginners to generally stay away from the vari-power scopes for sale out there.

 

BTW, it could be a cemented double, but many of the 50 & 60mm Towas have a ring spacer between the crown and flint. 

[LukaszLu]

Thank you for these valuable comments. I decided to buy this scope not because of its optical quality or material value, but rather as a witness to history. I thought it represents a short period in the development of optics market, when the spotting scope formula was searched - that's why it deserves attention. For a short time, this type of telescope flashed through the offers of several manufacturers, and then was replaced by much more compact zoom designs.

 

I think it is simply a historically interesting object and this is where I see its value, but I don't expect any special image quality. If I could get the quality of the later 70's zoom spotting scopes, it would be a very good result. I've got one - the 60 mm B.O.B. Optik zoom from 70's - a good reference for comparison.

[LukaszLu]

Another interesting feature of this model is the focuser. The rack is cut directly on the sleeve inserted into the tube. This quite risky solution requires stabilizing the position of the sleeve so that it does not rotate around its axis. This was solved by placing an incision on the other side of the sleeve for the screw leading the sleeve along the axis. In my copy, the screw has filed off a long time ago, and the sleeve turns sideways.

 

Of course, the question arises: what for...? If someone thought that the idea was to enable the use of the revolver also in other telescopes, by placing it in a focuser - that would be unfortunately wrong. The diameter of the sleeve is slightly larger than 0.96 '' to preclude unauthorized use of the revolver in other models. What a pity...

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