New spotting scope from KOWA (2 Viewers)

[binomania]

The new KOWA TSN-66 PROMINAR is a small but high-performance terrestrial spotting scope that stands out for its exceptional optical quality and innovative features. The main special feature of this spotting scope is the presence of an objective lens made of pure fluorite crystal, which provides outstanding sharpness and a brilliant image. You can find more information in my article on Binomania.it Novità KOWA - Nuovo spotting scope TNS -66 PROMINAR al puro cristallo di fluorite -

 

[etudiant]

The new KOWA TSN-66 PROMINAR is a small but high-performance terrestrial spotting scope that stands out for its exceptional optical quality and innovative features. The main special feature of this spotting scope is the presence of an objective lens made of pure fluorite crystal, which provides outstanding sharpness and a brilliant image. You can find more information in my article on Binomania.it Novità KOWA - Nuovo spotting scope TNS -66 PROMINAR al puro cristallo di fluorite -

The Binomania site used to have a link which provided an English translation, but I can't find it any more. Please help.
I'd be quite interested in Piergiovanni's appraisal, as this seem to be a worthy potential competitor to Swaro's wonderful ATS 65.

 

[Paultricounty]

The Binomania site used to have a link which provided an English translation, but I can't find it any more. Please help.
I'd be quite interested in Piergiovanni's appraisal, as this seem to be a worthy potential competitor to Swaro's wonderful ATS 65.

And the focuser system is better as well.

 

[Nivado]

Does anyone know if Kowa is planning to renew their 773 and 553 lines as well?

 

[Birdstarr]

I'm slightly disappointed in the announcement after the prelaunch literature I've seen. I was hoping for a genuinely new product and not just what is essentially an update of the 663 prominar. A new travel scope based on the 553 with interchangeable lenses would have been the better option for a new portable scope.

 

[mskb]

It appears that we are finally able to use a better Zoom eye piece on the 66! Objective lens improvements and dual focus are also very welcome.

 

[Yellow hammer]

Nice indeed. I can’t find wich prism system Kowa is using on this new scope… I read and read in manuals. Porro or roof???

 

[binomania]

Good morning everyone, I apologize for the lack of the translation plugin. i had it too because it was giving errors to some users and blocking the page. Now I put back the google one . If you have the will and time to try it you would do me a huge courtesy. Regarding the Kowa, I am now on vacation in Tuscany with the family, when I return, I should get a specimen for my video review. We will update, then, certainly. Thank you all for following me even though there are obvious language problems. I am honored that binomania is read by experienced birdwatchers like you

 

[dwatsonbirder]

Some initial comments from Backwoods pursuits (Apologies I think this is a US hunting channel?) on the new 66 vs the 773 can be found here.

 

[henry link]

Nice indeed. I can’t find wich prism system Kowa is using on this new scope… I read and read in manuals. Porro or roof???

I wondered about that too. The prism housings on the new 66 appear to be identical to the new 99s and 88s, so I'm not in much doubt that the straight model uses a Porro. The angled model probably uses the same Schmidt roof prism as the 88/99s instead of the Porro/semi-pentaprism used in the old angled 66.

Since the magnification range of the new 66 is identical to the 88 it must also have the same 500mm effective focal length. That would make the focal ratio a relatively high f/7.7, giving a good specimen the potential to have very well corrected aberrations. That is unless the designers decided that at f/7.7 they could get by with a doublet instead of a triplet up front.

 

[RobMorane]

Have anyone noticed the price?
Be ready:
TSN66-A: 2698 Eur with the 25x60 eyepiece on the official Kowa website.

That's already quite expensive, but you can find on the same website the
TSN-773 with the same eyepiece + the field stay on case at 2823 Eur.

I'm speechless...

 

[4th_point]

$3000 USD is what I see here. And the 770 is supposedly discontinued.

 

[4th_point]

Since the magnification range of the new 66 is identical to the 88 it must also have the same 500mm effective focal length. That would make the focal ratio a relatively high f/7.7, giving a good specimen the potential to have very well corrected aberrations. That is unless the designers decided that at f/7.7 they could get by with a doublet instead of a triplet up front.

Hi Henry,

I'm glad you mentioned that. I don't have a good sense for f/numbers but recalled your interview where you had mentioned f/8 for fluorite and f/5-6 for a fluorite triplet.

So f/7.7 for the new 66 seems promising for possibly low aberrations. Assuming a good sample. I was hoping that it would have the same focal length as the 770 and 880/88 when I heard rumors of prototypes being in the field with vendors.

My thought was that maybe there would be fewer lemons with the light not having to be manipulated at such a severe angle compared to the larger objectives. And I would prefer at least 60x!

Am I on the right track thinking that the rays from the periphery of the lenses have higher potential to create aberrations due to their angle relative to the shallower angle close to the axis? And a longer focal length would help mitigate that?

Sorry to bother you with such a basic question. I'm still trying to understand scope designs and limitations.

If anyone else wants to comment on my question please feel free.

Jason

 

[4th_point]

Regarding magnification, I was worried that it would be ~50x as I would prefer more magnification. I do value having the option of less than 25x on the other end though.

Makes me wonder if Kowa kept the same focal length to improve the robustness of the design or to simply avoid having to relabel EP units. They just went through that with the 99?

 

[Tringa45]

Regarding magnification, I was worried that it would be ~50x as I would prefer more magnification. I do value having the option of less than 25x on the other end though.

Makes me wonder if Kowa kept the same focal length to improve the robustness of the design or to simply avoid having to relabel EP units. They just went through that with the 99?

Hi Jason,

The relatively "slow" focal ratio of the Kowa 66 certainly offers the potential for better correction of spherical and chromatic aberration and combined with a fluorite objective element could very well make it the best corrected spotting scope, for its size, on the market.
The tests linked on a parallel thread suggest that it might have relegated the Swarovski ATS/STS 65 to a close second place in its class.

Personally, I think that 65 mm scopes are a very good compromise of portability and performance, but they do have their limitations and 60x magnification with a 1,1 mm exit pupil is going to result in a loss of brightness and the performance of your observing eye. Sixty times really does demand intense direct sunlight, where there is an attendent risk of mirage. In the field you would probably be using 25x-45x mostly.

Less than 25x is also not a practical proposition. I measured the AFoV of the TE11WZ eyepiece at 25x on my Kowa 883 at 56°. The "sealing" window in the scope body is only 23 mm diameter, so if this is also the case with the 66, an eyepiece with a longer focal length than 20 mm (25x) would either have a narrow AFoV or vignette severely.

John

 

[4th_point]

Thanks John, especially the details on the TE11WZ eyepiece.

Over the past ~12+ months I have owned four 60mm, one 65mm, and one 66mm. They do seem dim compared to a larger scope but I have still found them useful even at 60x with the 60mm scopes. That stated, I like a bigger scope when feasible!

Jason

 

[Hermann]

The relatively "slow" focal ratio of the Kowa 66 certainly offers the potential for better correction of spherical and chromatic aberration and combined with a fluorite objective element could very well make it the best corrected spotting scope, for its size, on the market.

Maybe. Depends on how consistent their build quality is, of course. Let's hope for the best.

Personally, I think that 65 mm scopes are a very good compromise of portability and performance, but they do have their limitations and 60x magnification with a 1,1 mm exit pupil is going to result in a loss of brightness and the performance of your observing eye. Sixty times really does demand intense direct sunlight, where there is an attendent risk of mirage. In the field you would probably be using 25x-45x mostly.

Agreed, although I find I can use my 60mm scopes up to ~50 even in somewhat dim conditions. In bright light 60x is no problem.

Less than 25x is also not a practical proposition. I measured the AFoV of the TE11WZ eyepiece at 25x on my Kowa 883 at 56°. The "sealing" window in the scope body is only 23 mm diameter, so if this is also the case with the 66, an eyepiece with a longer focal length than 20 mm (25x) would either have a narrow AFoV or vignette severely.

I personally like being able to use 20x quite a lot, even if the field of view isn't great. The reason is the depth of field - the difference between 20x and 25x is quite considerable.

Hermann

 

[Tringa45]

I personally like being able to use 20x quite a lot, even if the field of view isn't great. The reason is the depth of field - the difference between 20x and 25x is quite considerable.

Yes, I agree that would be useful but as you say, most 3x zooms have a rather narrow AFoV at the lower magnifications.
Swarovski used to make a fixed 20x eyepiece (23 mm focal length?) for the ATS/STS scopes and some years ago I tried out an NOS example on my ATM65 HD.
Compared to the 30x W it was however something of a disappointment with a shorter eye relief, a 60° field and pincussion distortion.
I think though, there were some good options for your Nikons.

John

 

[CMB]

Hi Jason,

The relatively "slow" focal ratio of the Kowa 66 certainly offers the potential for better correction of spherical and chromatic aberration and combined with a fluorite objective element could very well make it the best corrected spotting scope, for its size, on the market.

[Text Removed]

This scope looks very interesting.

I wish scope manufacturers were willing to make "slower" focal ratio scopes in order to handle chromatic aberration better. I'd gladly take a longer scope that controls CA better (even if it is a few ounces heavier) over a shorter scope that doesn't.

It is nice to see the new TSN-66 is slower.

 

[William Lewis]

The problem with longer f ratio's is you end up with a long small scope or a really long big scope.

66 is probably a good size for it though - low c.a is kowa's version of Leica colours or swaro flat fields and their none the worse for it.

Will