TSN-4 eyepiece question (1 Viewer)

I just got an old TSN-4 from a friend, and I'm currently using the 20-60x. To be honest, its really not easy to look through; very soft at the edges (anywhere over 20 or 25x) and my eyes keep searching and I can't really keep focus for very long (maybe just a problem with this eyepiece?).
I used a TSN-1 with a 25X that was very clear, and sharp to the edges; no problem with my eyes keeping focus or any weird stuff like that- it just worked. So, I'm thinking of buying the 30x wide for the TSN-4....would this help things, in terms of viewing ease and edge-to-edge sharpness?

Thanks for the help,
Andy

I had this eyepiece on my TSN-1 and found it to be excellent with easy viewing.I believe it's generally regarded as the top eyepiece for this range of scopes . I currently us the TSN 20W on my TS-613 which is also a very good eyepiece .





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Yes, A 20x wide or 30x wide would be excellent on the TSN-4 and would probably transform the scope assuming the zoom you bought with it was a very old one. I used a 30x wide for 15 years on a TSN-3 with no complaints.

Just bear in mind that Kowa released a range of 'new' eyepieces for the TS600 and 660 range of scopes a few years ago with twist-up eyepieces that are rated very highly (reports I've read claim that they are a bit better in image quality than the old TSN eyepieces which had rubber eye cups). These will also fit the original TSN scope bodies like yours (but not the TSN 800 series scopes).

It's also worth noting that there is also a new 45x wide and a new(ish) 20-60x zoom that are a considerable improvement (on the original zoom) and would work very well on a large aperture scope like yours.

Finally, I've read that it is also possible to attach an Opticron zoom eyepiece using the screw threads at the base of the bayonet fixing point on the Kowa scope body. Opticron make a range of zoom eyepieces, some of which are very highly regarded (I think it was the HDF zoom but could be mistaken?), so you have plenty of choices assuming funds allow. Unfortunately I have no experience of the Opticron eyepieces but perhaps some one else will come on and shed more light. The 20x and 30x wides would certainly be a good starting point, even if you bought a used one to save cash!

Steve

Seeing as how my dad has a TSN 4 and swapped his old TSN 20-60x for the Opticron HDF 20-60x I'm sure he'll be along to offer his first hand experience soon. :t:

Yes I use an Opticron HDf zoom with my TSN4 and find much better than the Kowa 20-60 zoom. Which at high zoom was TBH rather poor. With the HDF the image is brighter and the field of view is much better. Must point out that the zoom does not reach the 60x though but it still very usable to ID birds.

The eyepiece screws directly on to the thread on the scope body but to make it stable for use a washer needs to be put over the scope end of the eyepiece. You will have to make this yourself but it is no great hassle to do so.

Robert L Jarvis said:

Yes I use an Opticron HDf zoom with my TSN4 and find much better than the Kowa 20-60 zoom. Which at high zoom was TBH rather poor. With the HDF the image is brighter and the field of view is much better. Must point out that the zoom does not reach the 60x though but it still very usable to ID birds.

The eyepiece screws directly on to the thread on the scope body but to make it stable for use a washer needs to be put over the scope end of the eyepiece. You will have to make this yourself but it is no great hassle to do so.

Click to expand...

I'm thinking of getting an HDF 20 x 60 zoom to use on my Kowa TS-613 60mm diameter.
What will the magnification range be . I take it all Opticron HDF lenses will fit . What's the eye lense diameter on the zoom ?



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My 20 - 60 zoom on my KOWA TSN-4 has always been quite soft around the edges in the higher magnifications. I may have to look into getting a better eye piece.

Sugs

The lens diameter on my Kowa zoom which is the old version is 17mm, on the HDF the diameter is 23mm. Quite a difference! Not sure what the actual zoom range would be on the 613 but my son (Jaff) used the HDF on his 612 and actually made it a decent scope!

I also actually looked at the later Kowa zooms with the twist up eye cups to see if I should get that to replace my old zoom. TBH I really could not see that it was so much better.

The HDF was and is better for digiscoping.

I think it's something around 18-54x but don't quote me on that. I do think the Opticron is a better eyepice than the Kowa 20-60x for the 600/660 series. I'm using one on of those on my 824 but as I still had my 612 for a long while I was able to try both of them on it.

One thing though which my dad will back me up on, while the Opticron SDL zoom is optically slightly superior (won't fit on 610 series though), the HDF is a more digiscoping friendly eyepiece. If you weren't fussed about digiscoping Larry I'd look into the Opticron SDL 20-60x.

I am currently using the Opticron SDL V2 (part No 40936) on my TSN4. It makes a very good combination. I have tried it against a few of the current top of the line scopes (2 grand + ) and whilst not quite as good it is FAR from shabby.

To make this eypiece work properly on the TSN4 (or 1/2/3) you need a rubber/neoprene "O" ring of about 4.5 to 5 mm thickness to go inside the locking ring of the Opticron eyepiece. Otherwise it rotates when you try to use the zoom function.

spizellah said:

I just got an old TSN-4 from a friend, and I'm currently using the 20-60x. To be honest, its really not easy to look through; very soft at the edges (anywhere over 20 or 25x) and my eyes keep searching and I can't really keep focus for very long (maybe just a problem with this eyepiece?).
I used a TSN-1 with a 25X that was very clear, and sharp to the edges; no problem with my eyes keeping focus or any weird stuff like that- it just worked. So, I'm thinking of buying the 30x wide for the TSN-4....would this help things, in terms of viewing ease and edge-to-edge sharpness?

Thanks for the help,
Andy

Click to expand...

Yes! I had a TSN4 with 20x60 zoom from new. Frankly the zoom is poor. I bought a x30wide eyepiece and it transformed what is still an excellent scope.

If you can find one, go for the x30wide eyepiece.

Got an opportunity to compare my TSN4 + Opticron SDL V2 directly with the latest Leica 82mm + 20-60 zoom eyepiece - the owner of the Leica was VERY impressed with my Kowa - no it wasn't as good as his leica but he considered it to be fairly close. As dusk approached (we were observing towards the sun) the improved resolution and reduced flare of the Leica showed it's worth. When the light was good the scopes were pretty close and both were more than good enough, as the conditions worsened then the Leica began to strut it's stuff. Still I was VERY impressed with the "OLD" Kowa - for someone who does not have £2K + to spend on a scope it's a very viable option. For reference I paid just under £320 for the scope + eyepiece and no neither was secondhand (the TSN4 was very very old stock) - pays to wait and look around if you are on a budget!