Kowa TSN-99S light throughput (1 Viewer)

[pdwinter]

I'm looking to upgrade from a Kowa 883 and wondered if there are any published data for the percentage light throughput for the newer Kowa models - particularly the TSN-99.

Thanks

 

[Gzoladz74]

I had seen this somewhere but I cannot find it. If I remember it correctly, even though at comparable magnifications the 99 performs better than the 88, at their minimum magnification (25 vs 30) the 88 had better light transmission, what I found interesting.

I will try to find the source.

 

[Tringa45]

Kowa made some very minor changes in the transition from 883/4 to 88A/S and the biggest one was the price!
When viewed from the objective end, my 883 (2017 vintage) shows the least reflections of any of my instruments, so I think any coating improvements would be imperceptible. Similarly, the longer glass path of the 99 would account for less than 1% additional transmission loss.
Personally, I think the larger FoV and DoF at 25x minimum magnification vs, 30x will be more frequently of benefit than the rare use of a maximum of 70x.

John

 

[Gzoladz74]

Personally, I think the larger FoV and DoF at 25x minimum magnification vs, 30x will be more frequently of benefit than the rare use of a maximum of 70x.

John

I agree. This was my thought process when I decided for the 88 vs 99. You also have to carry the additional weight of a larger scope all the time and the extender works quite well when that additional reach is needed.

 

[pdwinter]

Thanks Tringa45 and Gzoladz74.

I see I paid £2357.83 at the beginning of 2018 for my 883 + 25-60 + 1.6x extender + stay on case - so there has been quite a hike in prices for the new model; about £1000 more with no extender and no stay on case!

I'll find a few local optics fairs and have a good look through the newer models before I decide