I have searched for this but because I don't know what I'm looking for I cannot be sure how to use these. (I can search for "why I'd want to")
A mirror lens I purchased has come with 3 filter elements, they are small and fit to the rear of the lens (where the lens joins the camera) not the front. Why? Cheaper to manufacture? Mirror lenses are immune to whatever damage UV can do to lens-lenses?
My question is why are there 3 and how do they differer, they are:
- KM-500 (phi) 30.5 SKYLIGHT 1A - visually it appears clear
- KM-500 (phi) 30.5 ND2X - slightly grey filter
- KM-500 (phi) 30.5 ND4X - quite a dark filter
I am sorry this might be a bit of a silly question but searching for "what to do with 3 filters that came with lens", I'm not even sure they're UV filters TBH.