Clear filter for telephoto?

Should I be installing a clear protective filter on my 500mm telephoto?
I have heard that it can remove some sharpness.
Dose anyone have an answer to this one?

Thanks,

Mike

Most super telephoto lenses don't have provisions for a filter to be mounted in front of the front element. The lens hood will protect the front element from damage.

Make sure when your carrying your lens over your shoulder that your hood is on. A guy I know was moving his a short distance to get a better angle with his lens facing up without the hood. Something fell out of a tree and nicked his lens. Whats the chance, but it can happen. The minolta 600f4 lens used to have a filter and it didn't affect the sharpness that I could tell. I would feel safer if they would provide for a filter.

Most fast superteles have drop-in rear filters, so you don't have the option of mounting a protective filter.

There are additional perspectives on protective filters here: http://www.naturephotographers.net/imagecritique/bbs.cgi?a=vm&mr=24282&b=va&st=0&la=3399&ph=2&sid=31977&u=31977

Isn't the outer most exposed glass on these lenses actually a built in protection element? And relatively inexpensive to replace?


Kent in SD

Kent is correct, at least on the Nikkors. The front element is optical quality flat glass and much less expensive than the other lens elements. Nikon used to advertise the fact that it served as protection. I do not know about other manufacturers, though.

The lens I have is a Sigma 50 -500 f 4-5.3
The guy at the store recommends the sigma uv filter.
Does anybody else own a sigma 50-500mm? . what aperatures does this lens work best at, and is it good and sharp out to 500mm?
Just wondering.

Thanks,
Mike

If the front element is either ED glass or fluorite, the lenses always have a protective glass. Usually these are flat, but some of the newer lenses have a meniscus element to minimize "ghosting".

I don't know anything about that lens Mike, but if you have it you can certainly test the sharpness yourself. The usual recommendation I've seen is to tape a crisp dollar bill to a well lit wall and use a tripod to hold the sensor plane parallel to the wall. Then you can move the tripod closer and further in order to test sharpness at different zoom levels, or apertures.

Mike: I have a Tokina 300mm f2.8 that came with a protective filter. I can't say it degrades my images but I rarely use it. Exceptions are when I'm in a very dusty or sandy area and when near the ocean and salt spray is an issue. Otherwise I let the lens hood be the primary protection. >=))>

The lens I have is a Sigma 50 -500 f 4-5.3
The guy at the store recommends the sigma uv filter.

This is sort of like going to MacDonalds, ordering a hamburger, and they ask, "You want a UV filter with that?" The margin in the filter is pretty good. As for the quality of the the Sigma 50-500mm it's actually said by owners to be pretty good. It might be one of the best bets for under a thousand dollars. The next notch up is likely a 300mm f4 with a 1.4x. Not quite 500mm though, and it is more money. The 50-500mm fills a niche for performance for the money.


Kent in SD

Thanks guys,
Maybe I'll keep the uv filter just in case. Ispend alot of time on the islands in Everglades national park, the sand and salt my be hard on the lens.

Mike