Spotting scope objective lens protection

[eaglemountainman]

I'm a big believer in filter lenses as (fairly) cheap protection for the objective lens on my spotters. I have an X4 on my little Kowa 554 and it does a very good job.

I just acquired a new Kowa TSN-884, and need to get a sacrificial lens for it, as well. My question is what lens are others using on their 883/4, and has it affected image quality, that you are able to discern?

 

[gr8fuldoug]

A high quality 95mm UV Filter will not affect your image quality. Give us a call, 516-217-1000, and we will take care of you.

 

[eaglemountainman]

Thanks, Doug. I'll probably be calling soon.
I only have experience with Breakthrough Photography and was wondering what others were using, and their experiences/opinions.

 

[BluMtn]

I use a UV Filter on my Kowa 99. It is a B+W F-PRO made in Germany.

 

[SikaSeeker]

Image quality will be degraded by each successive layer of glass. The filters kowa sell are expensive but likely high quality. Sticking a $20 filter on the front of a $3000 scope isn’t a good idea. You absolutely can see degraded resolution and sometimes brightness. Of course if you’re in a windy Sandy area or near the ocean it’s probably a good idea.

The coatings on older scopes at least were vulnerable to sea exposure and once they get damaged repair isn’t possible.

Even indoors looking through binoculars outside your windows impacts the image. And wearing glasses. Just think of layers. This is also why porro prisms are superior to roof prism binoculars. Less glass, simpler design.

 

[eaglemountainman]

@SikaSeeket
While that seems logical and sound, I have experienced no degradation in image quality or light gathering capabilities when using a good lens.
I think the key lies in using a high quality lens (e.g., Breakthrough Photography, or similar), vs a $20 piece of garbage. $150 - $200 is cheap insurance for high end, premium optics.

 

[SikaSeeker]

No disagreement here, if serious about protecting your pricey glass expect to shell out for more expensive glass to put in front!