4968 replies to this topic

[Mudburner]

Would that others gave away scopes to individuals who are truly interested in astronomy, rather than sitting in a corner of a room with the scopes, holding a shotgun.

Well, he DID say he would bring his bobcat over and do some dirt work for me in trade... so there is that. 

[andylsun]

I bought this Kenko 60/300 for not much on eBay. It came with a screw on dew shield.

i suspected it to be a vixen but the finder foot and the curve on the back of the lens cell don’t match any vixen or Tasco 9VR lineage. The curves seem more Towa or Carton style.

I’ve not yet found any maker marks or country of origin marks but will undo the focuser and lens cell later in the week. No marks on inside of lens cap or inside of focus knobs.

I’m not sure how the seller determined it was a Kenko.

drawtube is LONG with a 36.4mm thread on the end.

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Edited by andylsun, 04 November 2024 - 08:28 PM.

[Kasmos]

I bought this Kenko 60/300 for not much on eBay. It came with a screw on dew shield.

i suspected it to be a vixen but the finder foot and the curve on the back of the lens cell don’t match any vixen or Tasco 9VR lineage. The curves seem more Towa or Carton style.

I’ve not yet found any maker marks or country of origin marks but will undo the focuser and lens cell later in the week. No marks on inside of lens cap or inside of focus knobs.

I’m not sure how the seller determined it was a Kenko.

drawtube is LONG with a 36.4mm thread on the end.

They may have bought it new or had a box or some paperwork and packaging. 

 

In any case you can tell by the focuser/finder mount and the knobs.

This one is slightly different but they can vary a little and were generally like this at one time.

The Pentax J60 has the same style of those parts and the same Alt-Az mount as some Kenkos

 

As for the maker, there's a good chance Kenko was the maker themselves.

Edited by Kasmos, 05 November 2024 - 03:50 AM.

[andylsun]

They may have bought it new or had a box or some paperwork and packaging. 

 

In any case you can tell by the focuser/finder mount and the knobs.

Kenko-Focuser.jpg

This one is slightly different but they can vary a little and were generally like this at one time.

The Pentax J60 has the same style of those parts and the same Alt-Az mount as some Kenkos

 

As for the maker, there's a good chance Kenko was the maker themselves.

Awesome thanks. Yeah the more I looked at it I was beginning to wonder if they did build it themselves.

 

found some old catalogues that they mention they do the optical work and manufacturing in house. 
 

cool!

 

Waiting for the 36.4mm to 1.25” adapter before I get first light.

[andylsun]

In my usual “buy something from eBay then find I already own one”, my Parks 8x50 finder has a 36.4mm to 1.25” adapter.

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[Esso2112]

Been a while since I bought anything classic, but this set of eyepieces popped up.  The Gailand 10.5mm ortho was what caught my eye.  I have been looking for the silver version to complete my set (I now have complete sets of both the silver and black versions).  The other two are brass, labeled 1 and 0.25.  Glass is very nice on both.  The diagonal looks ATM.  

 

I tried the diagonal (a prism) and the eyepieces out by looking at a covered bridge from my house and all three gave clear and very nice views.  The eyepiece labeled 1 was exceptionally clear and crisp with good eye relief.  The 0.25 eyepiece has very limited eye relief, but was still had a nice image.  
 

Any ideas on manufacturer of the two brass eyepieces?

 

Edited by Esso2112, 05 November 2024 - 09:36 PM.

[deSitter]

Been a while since I bought anything classic, but this set of eyepieces popped up.  The Gailand 10.5mm ortho was what caught my eye.  I have been looking for the silver version to complete my set (I now have complete sets of both the silver and black versions).  The other two are brass, labeled 1 and 0.25.  Glass is very nice on both.  The diagonal looks ATM.  

 

I tried the diagonal (a prism) and the eyepieces out by looking at a covered bridge from my house and all three gave clear and very nice views.  The eyepiece labeled 1 was exceptionally clear and crisp with good eye relief.  The 0.25 eyepiece has very limited eye relief, but was still had a nice image.  
 

Any ideas on manufacturer of the two brass eyepieces?

 

IMG_3830.jpeg

IMG_3831.jpeg

IMG_3835.jpeg

IMG_3836.jpeg

Those are inches, so 25mm and 6mm.

 

-drl

[Esso2112]

Those are inches, so 25mm and 6mm.

 

-drl

That’s what I figured.  They are well made, but have no markings anywhere indicating manufacturer.  

[RichA]

I bought this Kenko 60/300 for not much on eBay. It came with a screw on dew shield.

i suspected it to be a vixen but the finder foot and the curve on the back of the lens cell don’t match any vixen or Tasco 9VR lineage. The curves seem more Towa or Carton style.

I’ve not yet found any maker marks or country of origin marks but will undo the focuser and lens cell later in the week. No marks on inside of lens cap or inside of focus knobs.

I’m not sure how the seller determined it was a Kenko.

drawtube is LONG with a 36.4mm thread on the end.

Disconcerting unless focus with a diagonal is achieved with a diagonal and the focus tube far out.  If not, the aperture is likely being cut-off, owing to the focal ratio and the length of the focuser tube.

[andylsun]

Disconcerting unless focus with a diagonal is achieved with a diagonal and the focus tube far out.  If not, the aperture is likely being cut-off, owing to the focal ratio and the length of the focuser tube.

The diagonal was just attached to the adapter and not a representation of the focal plane location! Sorry for misleading.

 

Focus on an object 100ft away is with the draw tube nearly fully extended. With a 8mm EP there’s less than an inch of outward travel left.

 

imaging tree branches against a blue sky showed no fringing.

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Edited by andylsun, 06 November 2024 - 08:05 AM.

[andylsun]

First Light

 

I dropped in a SVBONY SV305 and left it tracking for 3 hours on M33. Focus was done manually. Approx 2 arc sec per pixel image scale.

 

clear astigmatism on the stars but the colours seem good. I’ll try loosening the lens cell ring and see if that helps.

 

i know the image has technical flaws but im actually pretty pleased with the results. Straight out of APP with no further processing.

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Edited by andylsun, 08 November 2024 - 07:54 AM.

[deSitter]

First Light

 

I dropped in a SVBONY SV305 and left it tracking for 3 hours on M33. Focus was done manually. Approx 2 arc sec per pixel image scale.

 

clear astigmatism on the stars but the colours seem good. I’ll try loosening the lens cell ring and see if that helps.

 

i know the image has technical flaws but im actually pretty pleased with the results. Straight out of APP with no further processing.

What a cool little scope! Does it have a cemented or air-spaced objective?

 

-drl

[andylsun]

What a cool little scope! Does it have a cemented or air-spaced objective?

-drl

Cemented I believe. Will have it apart today.

I expected CA city and I didn’t get that.

[deSitter]

Cemented I believe. Will have it apart today.

I expected CA city and I didn’t get that.

I just picked up a Pentax J60c with a 60/300mm cemented objective. Not only was this surprisingly sharp for a cemented objective (no astigmatism at all), there was much less color than I expected. F/D is only 2.5 but it seems to perform at least at F/D = 3 like my 90mm f/10. Possibly the color correction is not as with a traditional achromat. My 60/400mm side scope (Towa) has as much or more.

 

-drl

[andylsun]

I believe the J60c is Kenko manufactured, correct? So basically the same scope.

[Bomber Bob]

Bushnell, Kenko, & Pentax definitely shared hardware during the 1980s.  As usual, can't be certain about the optics; but given they used the same re-branded eyepieces...

[deSitter]

I believe the J60c is Kenko manufactured, correct? So basically the same scope.

Honestly no idea! I will hunt for marks now

 

The 5x24 finder that it came with is also just excellent.

 

-drl

[andylsun]

Honestly no idea! I will hunt for marks now

The 5x24 finder that it came with is also just excellent.

-drl

I’ve not found any marks on my Kenko. Found multiple threads on various forums saying that the Pentax J scopes were suspected to be Kenko in part. Obviously not sure how traceable that is in reality

[andylsun]

Lens ring was VERY tight but once it started to turn was free moving. All back together with the lens ring very lightly touching the lens.

 

depending on the weather I may get to retest tonight.

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[deSitter]

Lens ring was VERY tight but once it started to turn was free moving. All back together with the lens ring very lightly touching the lens.

 

depending on the weather I may get to retest tonight.

The lens cell on the J60c is machined, not cast aluminum. The fittings of the scope are very reminiscent of an SLR film camera. It has a helical focuser with not much travel, and accommodates accessories via extension tubes. Takes a Vixen 1.25" adapter.

 

-drl

[andylsun]

Imaging tonight. See if it’s better with the non-hulked lens ring.

 

also I couldn’t help myself….

 

 

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[andylsun]

Here’s the results after the lens cell ring loosen. I actually don’t think it made much difference at all.

 

will still play around with it a bit more, and try a bigger sensor. The SV305 is 5.6x3.2mm. Then it might end up on the shelf. Any measurements worth doing? Check the lens alignments with each other? It’s cemented so not a terrible amount of stuff I can do to it.

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Edited by andylsun, 10 November 2024 - 07:39 AM.

[CHASLX200]

Good shots dot.

[deSitter]

Here’s the results after the lens cell ring loosen. I actually don’t think it made much difference at all.

 

will still play around with it a bit more, and try a bigger sensor. The SV305 is 5.6x3.2mm. Then it might end up on the shelf. Any measurements worth doing? Check the lens alignments with each other? It’s cemented so not a terrible amount of stuff I can do to it.

Well, I'd say superfinder for your rebuilt Newtonian All that focus travel means you can use a RACI diagonal. Its future as a camera lens is dark

 

Try a strong green filter and B&W imaging?

 

-drl

Edited by deSitter, 10 November 2024 - 10:09 AM.

[andylsun]

Well, I'd say superfinder for your rebuilt Newtonian All that focus travel means you can use a RACI diagonal. Its future as a camera lens is dark

Try a strong green filter and B&W imaging?

-drl

I will try a mono camera and single colour filters for kicks but I think as both yellow and blue stars show it the astigmatism isn’t confined to one wavelength.