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The Kowa Eyepiece Compatabiliy Thread (1 Viewer)

Hi All,

I have a Kowa TSN-4 that I had intended on fitting with the Opticron HDF 40831 as others here have done. I picked the scope up recently for a song but the old 20-60 zoom is not great.

The biggest issue I'm facing is Brexit related! While the 40831 is readily available in UK it is not in Ireland. Ordering online is an option but the import charges to Ireland add nearly 30% to the cost and because of the paperwork involved, shipping costs have also increased significantly.

A "local" (other end of the country!) camera shop has the 40809 available but I'm not sure if this is compatible. From the photo on the Opticron site, it seems to lack a female thread to allow it to screw onto the Kowa scope. Has anyone here any experience with this eyepiece on a Kowa TSN 1-4?
 
Hi All,

I have a Kowa TSN-4 that I had intended on fitting with the Opticron HDF 40831 as others here have done. I picked the scope up recently for a song but the old 20-60 zoom is not great.

The biggest issue I'm facing is Brexit related! While the 40831 is readily available in UK it is not in Ireland. Ordering online is an option but the import charges to Ireland add nearly 30% to the cost and because of the paperwork involved, shipping costs have also increased significantly.

A "local" (other end of the country!) camera shop has the 40809 available but I'm not sure if this is compatible. From the photo on the Opticron site, it seems to lack a female thread to allow it to screw onto the Kowa scope. Has anyone here any experience with this eyepiece on a Kowa TSN 1-4?
Apologies all. I missed post #50 that pretty much answers my question above. 😳
 
On topic but slight tangent; Can you do this Opticron zoom on TSN 663 using the 40925 adapter. And can you use the SDL v2 lens.
Also, what is the accessory thread of the tsn663 and that of the TSN 823M, please if anybody knows.
As my Baader zoom fits my TSN 823m and as the TSN 663 has a smaller thread could you use a "STEPPING DOWN RING" between the Baader and the Acc' Thread for it to work.
thanks
 
Hi,

I guess I'm a bit late... but this spring had some RL things which left less time for internet...

The adapter part number 40925 is for those HDF fixed mag EPs that have a male thread... of the current lineup that's only the high mag 40861 but there is plenty of discontinued models...

I have this adapter and the 40861 and it works on both my TSN-3 and 613 for 85x but it didn't reach focus farther away than 100m or so on the TSN-3. I have not tested infinity focus on the 613 - and probably won't this weekend looking at the weather forecast but will keep that in mind.
EDIT: Quite unexpectedly there was a waxing gibbous moon visible low in the sky between the clouds... the 40861 with 40925 comes to infinity focus on the 613 with a little bit over available... in today's not great seeing 85x was certainly over the top for the 60mm objective.

The later HDF fixed mag EPs with the collar as well as the HDF and SDL zooms will have the correct threading to fit the accessory thread of the small body Kowas directly - you might need need some rubber o-ring or washer to fully tighten it.
But on some combinations the front element of the EP will hit the protective window of the body (most single digit TSN bodies don't have a protective window and thus no problem) or be too wide to fit inside (SDLv2 on 613). Some careful testing and fiddling around with washers might help in the former case, but you also might get too far out to reach infinity focus that way. If you go birding only and think birds on other planets are not worth it anyways, go ahead!

The adapter 40927 will take care of both problems, but will most probably turn your spotting scope into a very close range instrument due to it's length...

PS: Small body thread size is M41x0.75 if memory serves, no clue about 820 series...

Joachim
 
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