Using KOWA TSN-EX16S (1.6x) Extender with a TSN-823? (1 Viewer)

[Grando]

Has anyone tried using the 1.6 EX16S extender (the one for the 663) with an 823? According to the Kowa website it will work "in combination with a TSN-EC1A adaptor fitted onto the Kowa eyepiece (see: https://www.kowaoptic.com/media/pdf/f2/9b/b4/Kowa-System-S-A4-English.pdf).

I have the adapter and eyepiece, but am a bit dubious as to how the extender will attach to the 823, given that the threads where I assume it screws onto (where you attach the eyepiece cover) are a different diameter on a 663 etc and an 823. The 823 is wider.

Anyway, has anyone had a go with this setup?

 

[jring]

Hi,

while I own neither an 820 series scope nor the adapter, I would try the following after getting my EX16S from the 613...

- screw the TSN-EC1A with its female thread (see image in link) onto the accessory thread around the EP mount on your 820 body

Kowa Eyepiece Converter: TSN-820M Eyepieces to TSN-880/770

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- screw the female threads (M40.5x0,5 iirc) on the EX16S onto the male threads around the bayonet mount of the TSN-EC1A (see image in link)

Kowa Okular-Konverter TSN-EC1A TSN-660/600 Okulare an TSN-820/820M TSN-EC1A - fotokoch.de

Kowa Okular-Konverter TSN-EC1A TSN-660/600 Okulare an TSN-820/820M jetzt günstig einkaufen bei fotokoch.de, ihrem Onlineshop mit großer Auswahl an Fernglas Zubehör. Preiswert, schnell, zuverlässig.

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- if that does not fit, take apart the EX16S by unscrewing the knurled ring like this to expose a larger diameter female fine pitch thread (was too lazy to measure) and try that.



- If that works, attach EP into the bayonet mount of the EX16S and enjoy the view.

- If not - maybe ask Kowa...

Cheers,

Joachim

 

[Grando]

Thanks Joachim – that looks promising. I haven't actually got at EX16S, but wanted to check how it might work before I tried to acquire one! But good to see how you can remove the inner part to reveal a wider thread which should attach to the larger 820. Do you notice a big drop-off in quality when you use the adapter on your 613? I was interested in getting one to make the 45x eyepiece I have (which is 50x, I think on the 820) into an 80x for winter sea-duck watching etc.

 

[jring]

Hi,

the extender is mainly used with the 613 and a 30 wide to make it a 48 wide... great views unless the light is really bad. When I still had the current 20-60 small body zoom, I also tried that with extender for 96x. The 613 was starting to struggle a bit with that - still good enough for an ID in good light, but starting to soften up.
Which is kinda expected as we're getting close to its maximum useful magnification of 120x (rule of thumb is 50x per inch of aperture).

My cherry example of TSN-3 was still great with that combo at 96x in good light, but normally, I like the adapted SDLv2 cranked to its max of 54x on there better than the Kowa zoom alone, so the latter was let go. I have some Opticron 5mm EP for 84x for the rare occasion that I need that reach.

Joachim

 

[Grando]

Thanks Joachim. Sounds promising!

 

[Grando]

Thanks Joachim. I now have acquired a TSN-EX16S and it works very well, at least in initial trials, with my 823. To make it work you simply unscrew the furled ring, as in your photo, and it then screws directly onto the thread surrounding the eyepiece. The EC1A adapter is then fitted onto one of the 663-series eyepieces and then twisted on in the usual manner into the 1.6x converter. It's a good sharp view and will be nicely usable in suitable seeing conditions with my 45x eyepiece (50x on the 823) - turning it into an 80x eyepiece for distant views.

One thing to point out is that there's no way to use the Baader Hyperion Zoom IV with this - just Kowa 663-series eyepieces with the EC1A adaptor.