Anyone run a protective clear lens filter on their spotter?

[boom]

Lens caps are annoying. A clear filter would work? I use them on cameras and just leave the cap off. Any experience?

 

[colonel00]

As with cameras, you may have some performance loss with a filter. Even a clear one is going to limit and possibly "corrupt" the light reaching the objective to some point.

 

[Thinkingman]

If I used a spotter, it would have a polarizing filter on it.
Cuts haze, no real image loss.
Protects glass.

 

[colonel00]

Are you talking about a CPL? I think you would still lose a stop or two of light with the CPL. This may not be that noticeable in good light but I think it would really hurt performance in low light which is usually when you want good glass to step up above a mediocre scope.

 

[bhylton]

I always wondered about putting some of that invisashield phone screen protector on a spotter. that stuff does not seem to block much light and it would sure protect the lenses

 

[Thinkingman]

I posed the idea of a polarizing filter to my buddy who is a professional camera operator in Hollywood:
Aproximately one and a half f-stops. It depends on the individual polarizer, the angle to the sun (45° is usually maximum polarization) and how much you dial it in if you can rotate it. Need a spot meter to read actual light loss.

 

[Matt Cashell]

As mentioned filters cut light and often introduce glare, so I don't typically use them. However, if the specific conditions were really poor (blowing sand, etc.) I could see the trade offs being beneficial.

 

[colonel00]

If anything, I'd look at a UV filter. However, I'd still probably remove the filter for use in low light. At that point, I don't know that it's much different from just dealing with a lens cap. The other consideration is perhaps a different lens cap option that might be less annoying?

 

[Thinkingman]

If anything, I'd look at a UV filter. However, I'd still probably remove the filter for use in low light. At that point, I don't know that it's much different from just dealing with a lens cap. The other consideration is perhaps a different lens cap option that might be less annoying?

UV filter is what I meant to post in my original.
Not polarizing.
Good idea.
I will ask my buddy if he has any experience to lend.

 

[Thinkingman]

UV filter has no light loss.
I would use one for protection.
Eastern Washington has fine volcanic ash which is a good way to get scratches if you don't clean your optics carefully.

 

[colonel00]

Correct. There shouldn't be any light loss but there still may be some image degradation. You wouldn't want to use a cheap/low quality filter as you will basically be putting a cheap piece of plastic/glass in front of your objective lens which defeats the purpose of having nice glass. So now you are looking at potentially spending $100 on a UV filter. If the volcanic ash or anything else is enough of an issue that it may damage the objective of the spotting scope, it most definitely will have the same effect on the UV filter. Thus, you are potentially buying new filters every year or so. There are still other potential issues like color degradation, reflections, flare and other artifacts that can occur as well. I'm not saying it won't work but just pointing out things to think about before going that route. Someone may find that it works perfectly fine for them and that's great.

I'll add one other thing to consider. While we all want to keep our gear pristine and protected, when talking about glass, be it a spotting scope or camera lens, the front element can have quite a bit if "damage" and still perform quite well. Again from a camera perspective, I have lenses with some scratches and they quite often have a good bit of dust on them. You cannot see this in the photos taken though. However if you have dust on the eyepiece of a scope or sensor of a camera, this will be much more noticeable.

Here is a fun article showing an extreme example.

http://www.lensrentals.com/blog/2008/10/front-element-scratches