Older Kowa TSN-3 performance? (1 Viewer)

[slingworks]

Curious how the older TSN-3 florite Kowas compare to the newer generations like the 883 and 770? If used with a modern eyepiece are they anywhere close to being comparable?

I happen to have a TSN 614 and 613..I'd say they're the best scopes I've owned especially for the cost...But wonder how the older TSN 1,2,3,4 stack up as a vintage scope?

I saw a couple at the Nationals that were intriguing, looked surprisingly good hanging on a scope stand,but I didn't get to examine closer....

 

[PYRTLE]

TSN 3 is a very good vintage telescope. I owned one with a x30w and a 20-60 zoom. The 883/4 performs much much better IMO both optically and ergonomically whilst also being water / fog proof. The TSN1 and 2 ( non fluoride ) would be poor compared to your 613 and 4.

 

[jring]

Hi,

it really depends on sample variation - my cherry TSN-3 body with a current EP (Opticron SDLv2 or current Kowa 20-60 with or w/o Extender) does deliver an image comparable to current alphas - usually favorably so...
Star test is also not too shabby on this one.

I have another TSN-3 body is ok, but not more. Best used with 30 wide.

So if your 61X examples are good, kepp 'em unless you need sth larger.

Joachim

 

[johnf3f]

I use the TSN 4 (straight version of yours) and it performs very well. Not quite up to today's alpha scopes but still very good and well worth holding on to.

 

[slingworks]

johnf3f, what would you consider to be the weak points in comparison? Are they producing a lower resolution or perhaps less light transmission? Just curious what to look for. Are you using a modern eyepiece?

 

[jring]

Hi,

johnf3f is using an SDLv2 like me, iirc - he introduced me into the Opticron zoom hack.

Image brightness will of course be better in a current 85-88mm alpha - first and foremost due to more aperture and of course modern coatings help. After all, the TSN-3/4 series are single coated.
But it has to be said that situations where this difference really matters are quite rare - maybe the first and last ten minutes of dawn and dusk.

The larger aperture will also lead to a higher theoretical resolution, but that is only relevant in cases of perfect instruments - which unfortunately are kinda rare in spotting scopes.

In reality it all depends on how well the lenses of a certain example were figured and whether they were correctly mounted to avoid pinching. You will only see quite blatant defects during normal daylight observation at spotting scope magnifications. Normally the focus of one instrument is just a bit less snappy than in another one or some plumage detail at maximum magnification is a bit better visible in direct comparison.
Observing a resolution target will make differences clear, a star test will also show what defects are present to an experienced observer.

Joachim

 

[johnf3f]

As "jring" says my main eyepiece is the Opticron SDL V2 - which works pretty well. I also use an Opticron HR series eyepiece (with insulating tape wrapped around it and stuffed the the back of my Kowa!) it works well too - maybe a bit better - but it is not a zoom.

 

[slingworks]

I appreciate the experience and replies....I just picked one up today.

It's in great condition and comes with a brand new TE14WD Kowa eyepiece. I won't get a chance to test it for a few days but I have no doubt it's a good piece. I gave $575 for it. Not sure if it's on the high side or not. I have no idea what the market is on these here in the US as I really don't see them around.

I have had a full size TSN 82SV hanging on my Ewing Stand for a few years, but I've decided to sell it and replace it with the TSN-3. I also have an extra 25xLER eyepiece and one may go on it as well. If I don't like it I can always list it in the classifieds

I looked into the Opticron Eyepiece mentioned and it appears the HR eyepiece may be discontinued?
Seems that they're very highly regarded.

 

[jring]

Hi,

with a new 30 wide included it's a great price - the EP is like $300 alone. Let us know how you like it.

Joachim

 

[rollingthunder]

I have half a dozen scopes but still use my 40yo Kowa TS2 (angled 22 WA eyepiece) cracking bright image and nicely balance/length for handheld and resting on walls etc:t:

Laurie -

 

[slingworks]

Ok I finally got to test my "new" TSN-3.

The scope overall is flawless. Not a chip or defect anywhere.

Very clean inside. I saw one piece of dust sitting on the rear prism, that's it.
It's serial 134xxx range and doesn't have the window under the eyepiece.

Optically it's very sharp and seems pretty color neutral. Focus is smooth, feels better in use than I expected. The 30x wide on it works great. No real complaints I could find anywhere. Looked at a bit of wildlife with it. Tested it on my usual "Resolution" targets...400yd fence posts with wire and staples, electric fence insulators (White and yellow). 800 yd oil pump w/sucker rod.....bolts on a road sign 310yds...and Locust posts at 650 w/cracks.

Very sharp. Overall though I'd have to say the TSN 613 I have is literally identical in all practical aspects.

Overall I'd say a great optic.

 

[johnf3f]

Ok I finally got to test my "new" TSN-3.

The scope overall is flawless. Not a chip or defect anywhere.

Very clean inside. I saw one piece of dust sitting on the rear prism, that's it.
It's serial 134xxx range and doesn't have the window under the eyepiece.

Optically it's very sharp and seems pretty color neutral. Focus is smooth, feels better in use than I expected. The 30x wide on it works great. No real complaints I could find anywhere. Looked at a bit of wildlife with it. Tested it on my usual "Resolution" targets...400yd fence posts with wire and staples, electric fence insulators (White and yellow). 800 yd oil pump w/sucker rod.....bolts on a road sign 310yds...and Locust posts at 650 w/cracks.

Very sharp. Overall though I'd have to say the TSN 613 I have is literally identical in all practical aspects.

Overall I'd say a great optic.

Happy new toy!

 

[Binoseeker]

Multicoated

The TSN-3 and -4 seems to be multicoated according to a KOWA ad here:

https://sora.unm.edu/sites/default/files/journals/nab/v049n01/front.pdf

Anyone has a specification or manual in pdf to share ?

 

[jring]

Hi,

there might be a few late production examples which are multicoated and possibly have the protective glass above the prisms which prevents the use of Opticron HDF and SDL zoom EPs.

The two old examples I own are single coated for sure.

Joachim

 

[Binoseeker]

Hello,

Can the protective glass be removed?
Is there a way to see if multi- or singlecoated?
It seems hard to find specification, manual, etc, tried to search for it.

Thanks,
Anders

 

[jring]

Hi,

the new examples with protective glass I have seen in internet images said multicoated on the right side (from EP). Also if you look at a single coated objective lens, you will see quite a bit of reflection - usually bluish to purple. A multicoated objective lens will show quite a bit less reflection and what is left will vary in color.

As for removing the protective glass - I don't know. You will of course loose the waterproofing it provides.

Joachim.

 

[Binoseeker]

Ok,

I got this pdf from a nice person at Kowa, thanks for the info.
I have asked some additional questions about "multicoating".

 

[mayoayo]

I don't think they are as old as to be single coated..Optics of that vintage and older ,in high standard optics used multicoatings .The Amber and bluish hues were the coatings of the day,but that does not mean necessarily single coated.On the other hand I had a copy of the 32X wide FOR THE 823 SERIES ,that looked single coated.I recall having seen a number of variations on the various tsn4 and the one tsn1 I owned ,for different vintages.The Tsn1 was newer and had some pink with the blue ,very similar to my current 823,definitely MC..most of the tsn4 had all blue ,but quite deep,I would say multicoated..The 823 started with the blue/pink and went to green/pink,of course all multicoated

 

[jring]

Hi,

as for my TSN-3 copies, I'm quite sure they're singlecoated. I'm also not sure if the fluorite crystal back element is coated at all as back then coating fluorite crystal was in its infancy. Will have to check when I get back home (and thus to a less wet climate - fluorite crystal also doesn't like water a lot).

Also a singlecoated doublet objective is not the end of the world.. we loose 1.3% per surface as opposed to 0.3% per with MC. Even an uncoated back element will certainly not make the scope unusuable with 4% loss per surface.

We certainly want multicoatings for the stacks of glass that modern zoom eyepieces are!

Btw, the 60x EP for the TSN-1/2/3/4 series I have is singlecoated too and with that one it shows it's noticeably darker than a modern multicoated 20-60 zoom at 60x - despite being fairly simple in design and having quite a bit less surfaces than the zoom.

Joachim

 

[Binoseeker]

Fake?

I am looking at a TSN-3 with protective window, marked multicoated on the sides of prism housing.

I shined a green laser through the front lens and expected to see no trace of the beam in the lens, between the first and second reflections,due to fluorite, but there is a trace. See attached photo.
Joachim, do you see any traces in your two TSN-3s ?