which filter (1 Viewer)

i am about to buy a filter for my 400 5.6 and got to wondering which one
it is purely to protect the glass
was thinking of either a uv or skylight
which filter do do you guys use and any reason why
thanks
rob

I use skylight filters myself just to protect the front element.

I do not use filters myself but prefer to use the lens hood to protect the front element. Touch wood it has done a good job so far !

Skylight filters have a slight pinky-orange tint to 'warm-up' mid-day light and cut through haze. UV filters are clear and often used for protecting lens/scope front elements.

Using filters on any lens will cause some degree of image degradation - it is another glass surface for the light to bounce around. This effect is more apparent using cheaper filters and when placing any filter on longer telephoto lenses (e.g. your 400/5.6).

I don't put a protective filter on any of my lenses - extending the lens-hood when you are using the lens should provide enough protection against scratching etc from physical contact.

If that makes you nervous, think about the big 500 and 600mm lenses - it is not practical to put a filter on the front but we still happily use these lenses out in the field in all sorts of conditions...

I tried a protective filter when I first got my 400mm f5.6 but took it off after a few weeks because of the image degradation - have not used one since but Always use the built in lens hood.