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new eyepiece for tsn 1 (1 Viewer)

jangodog

Retired
Hi. i got this 30x77 wide eyepiece on my Kowa tsn 1. It works fine but is it possible to get a zoom for my scope with more range?
 

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Hi.Yes, already got some advice from Joachim on the same topic but posted in the wrong section of
the forum:) So now i just have to look for that particular eyepiece online:)

Thank's to the both of you:)
 
Hi,

ok, if you are set on a zoom despite my pitch for the 30 wide, so be it ;-)

Also all credits for this hack need to go to BF user johnf3f who told me about this option (I think he uses the HDF on his TSN-4) and probably others on here.

The two Opticron zooms known to work are the HDF zoom (part number 40862) and the SDLv2 (part number 40936), both resulting in a 17-53x magnification on the Kowa. You can send a mail to [email protected] and they will either take your order or refer you to a local dealer (if any exists in Denmark).

Before you order anything, please check if you can actually reach the prism surface with a q-tip or toothpick when looking through the EP bayonet flange of your body. There are some rare later models of TSN-1/2/3/4 which have an optical window in front of the prism assembly in order to hermetically seal the body. Unfortunately this limits space and if present we need to do some measurements to make sure the Opticron EPs fit. If you have that window in your scope, please let me know...

You also need a rubber o-ring as a spacer as the female M41x0.75 thread on the opticron EPs is a bit longer than the male accessory thread on the Kowa bodies - I would recommend a cross section of 4-5mm and an inner diameter of 32mm or larger - I could only get a larger one in 5mm and cut out some pieces until it fit snugly.

Regards,

Joachim
 
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Kowa TSN-1

Hi , I also use the Opticron HDF zoom on my TS-613 .

It's a great combination and the lenses often come up for sale on a well known auction site .

I don't think you'll be disappointed.

Kind regards,

Graham
 
Note JRING's comments = good advice!

I use the Opticron SDL V2 on my Kowa TSN 4 (same mount) and it works pretty well too! A while back I let another birder try my SDL V2 on his Opticron scope and he preferred it to the HDF equivalent - however the HDF is cheaper.

My TSN 4 does not have the window between the mount and the prisim so there is nothing for the front of the eyepiece to contact. Also the thickness of the spacer ring is nearer 3-4mm in my case. I just progressively shaved down a Neoprene O ring until I got a nice fit - never works loose!

Note a few of the higher end Opticron fixed eyepieces fit as well - generally it is the ones with the external collars rather than the ones with threaded barrels.

Have fun!
 
The Zoom will give you more reach, but chromatic aberration would creep in the image pretty fast when you past that 30X point in a standard glass scope like the TSN 1..You will have a larger image zooming in ,of course,but the relatively clean image you get at 30X ,is going to suffer some unpleasant side effects.
If You are going to spend a couple of hundred euro in a zoom,or even more for the SDL V2(close to 300 eu), you need to consider if the expense is worth of the scope, because for just that much or close to that amount ,You could find a fluorite version of the scope, a much better upgrade in my opinon,than the eyepiece
 
The TE-9Z is the current 20-60x Kowa zoom for that mount. It's a fabulous eyepiece. Much better than the original zoom that went with the TSN-1. -2, -3, and -4. We just sold one to a TSN-2 user on Saturday.
 
The TE-9Z is the current 20-60x Kowa zoom for that mount. It's a fabulous eyepiece. Much better than the original zoom that went with the TSN-1. -2, -3, and -4. We just sold one to a TSN-2 user on Saturday.

And the Opticron SDLv2 is even better on TSN-1/2/3/4 with a rubber o-ring as a spacer, but both might be a bit of a waste on the plain glass bodies since they are sharp up to 40 or 45x at max and the zoom EPs are fairly narrow below their maximum magnifcation.

In my opinion the 30x wide is the best option on TSN-1/2 - very sharp and bright at that mag and super wide field.

Joachim
 
Note JRING's comments = good advice!

I use the Opticron SDL V2 on my Kowa TSN 4 (same mount) and it works pretty well too! A while back I let another birder try my SDL V2 on his Opticron scope and he preferred it to the HDF equivalent - however the HDF is cheaper.

My TSN 4 does not have the window between the mount and the prisim so there is nothing for the front of the eyepiece to contact. Also the thickness of the spacer ring is nearer 3-4mm in my case. I just progressively shaved down a Neoprene O ring until I got a nice fit - never works loose!

Note a few of the higher end Opticron fixed eyepieces fit as well - generally it is the ones with the external collars rather than the ones with threaded barrels.

Have fun!

Hi all,

I have had the Kowa TSN-3 with 30x WA lens for many many years, and have been very happy with it. But I felt that I needed a zoom option, so bought an Opticron SDLv2 eyepiece as discussed on this thread. I also considered the Kowa TE-9Z, but the eyepiece is narrower and I thought the Opticron option would allow me to do digiscoping (which is really difficult with the current 30xWA). It would also give me the option of buying a smaller [Opticron] scope body that I could use with the same eyepiece, for travel.

As advised here I bought a 4mm thickness O ring. The setup works fine initially but the eyepiece can move slightly, which makes the image really blurred. Do I just need a thicker O ring to pad out the space between the eyepiece and the scope?

Regards,
Mike
 
Hi Mike,

where do you put the O-Ring? It needs to go inside the lug on the eyepiece above the female thread. Just cut it open and shorten as needed to put in there. There's a small grove where it stays without falling out.

If that's what you did, 5mm it is. My zoom sits very tight - never turns a bit when zooming let alone wobble.

Joachim
 
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Hi all,

I have had the Kowa TSN-3 with 30x WA lens for many many years, and have been very happy with it. But I felt that I needed a zoom option, so bought an Opticron SDLv2 eyepiece as discussed on this thread. I also considered the Kowa TE-9Z, but the eyepiece is narrower and I thought the Opticron option would allow me to do digiscoping (which is really difficult with the current 30xWA). It would also give me the option of buying a smaller [Opticron] scope body that I could use with the same eyepiece, for travel.

As advised here I bought a 4mm thickness O ring. The setup works fine initially but the eyepiece can move slightly, which makes the image really blurred. Do I just need a thicker O ring to pad out the space between the eyepiece and the scope?


Regards,
Mike

The SDLv2 eyepiece is stiff to zoom though, the HDF is much easier.
 
Hi Mike,

where do you put the O-Ring? It needs to go inside the lug on the eyepiece above the female thread. Just cut it open and shorten as needed to put in there. There's a small grove where it stays without falling out.

If that's what you did, 5mm it is. My zoom sits very tight - never turns a bit when zooming let alone wobble.

Joachim

Hi Joachim,

Thanks for the quick response. I'm not sure what you mean by this, but the O-ring is 32mm inside diameter, and 4mm cross-section. I've attached two photos, one showing the eyepiece with the O-ring and the other without the O-ring. I thought the O-ring was just acting as a spacer - maybe I'm doing something wrong?

Mike
 

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Looking at others posts I think the required thickness of the "O" ring may vary from scope to scope. Mine is a thicker ring shaved down with a Skin Graft blade (they are great - wish I could get more!) and is 4.2 to 4.4 mm thick - not bad for freehand cutting!

Mine is solid and has been for several years. Yours may need a slightly thicker or thinner spacer. Something in here will fit:

http://www.ebay.co.uk/itm/419-Piece...039754&hash=item27de16581a:g:lgYAAOSwVL1WEAN5

Though you may need to reduce the diameter by cutting out a small section - I did.
 
Hi,

ok the position looks ok - my o-ring was too wide and needed cutting out a bit to fit. Then you probably should try a 5mm diameter example - like me.

Joachim
 
I'm pleased to report that with the 5mm O-ring the eyepiece sits firmly and doesn't wobble or move when you change the zoom.

Thanks all for your help!

Mike
 
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