Kowa TP-95FT Protective Filter On TSN-88 (3 Viewers)

[ajfossey]

Two areas I’d be interested in hearing experiences and thoughts on regarding the use of a genuine protective filter on the new Kowa TSN-88 objective element.

• Previous models and implementation resulted in the protective filter moving with the lens hood. My understanding is that this is not the case with the new TSN-88 model. The protective filter fixes to the objective, and the lens hood remains useable; effectively sliding over the protective filter. Is this correct?
• Are there any optical or other disadvantages in using such a filter? Assume a genuine Kowa protective filter is utilised purchased from a genuine dealer, e.g.: not a cheap alternative procured from E-Bay etc.

Thank you.

 

[ajfossey]

Two areas I’d be interested in hearing experiences and thoughts on regarding the use of a genuine protective filter on the new Kowa TSN-88 objective element.

• Previous models and implementation resulted in the protective filter moving with the lens hood. My understanding is that this is not the case with the new TSN-88 model. The protective filter fixes to the objective, and the lens hood remains useable; effectively sliding over the protective filter. Is this correct?
• Are there any optical or other disadvantages in using such a filter? Assume a genuine Kowa protective filter is utilised purchased from a genuine dealer, e.g.: not a cheap alternative procured from E-Bay etc.

Thank you.

Answering my own question with respect to the first query.

Having purchased and now fitted the Kowa protective filter, I’m able to confirm that the lens hood is able to move freely over the filter. I’m also able to continue with the attachment of the objective lens cap when putting the scope away.

I’ll return any findings with respect to my second query after some time in the field.

 

[Hermann]

I meant to reply to your second quety but never got round to it ... Sorry.

Anway, I've been using high-quality filters on my Nikon scopes almost forever, filters made by Nikon, Canon, B+W and Zeiss. I even use an old Leitz filter on one of my ED50s. IME experience such filters have a negligible influence on image quality. In fact, I can't see any.

There are two disadvantages: On wet, humid days one may get some condensation behind the filter. If that happens, I take the filter off as soon as I get home and let both the filter and the objective lens dry in their own time. The second disadvantage is that you may get some more reflections if you don't use a lens hood.

Cheap filters are a totally different matter, of course ...

Hermann

 

[ajfossey]

Sounds positive Hermann. Thank you.

 

[hoan]

I use Cir POL on my TSN-88. It accentuates the contrast and also removes flare/reflection on water surface. More clearer contrasted image. And yes, I can also slide out the lens hood.

 

[ajfossey]

Thank you Hoan. I certainly noticed no deterioration in the quality of the optics with the Kowa filter. I will review harder over the coming weeks to see if I can notice any change, as you appear to have, with the Cir POL in a positive way.