Clarify filters names and functions: ND vs UV vs CP ?

TrayBoz · May 30, 2017

Can someone please clarify me the difference between these filter designations?

I know the difference between polarized lenses vs non-polarized lenses.

What is the difference between ND filters, UV filter, and CP filters?

What do the letters CP stand for?

When would I use each type?

Thanks in advance.

Kilrah · May 30, 2017

Choosing a Camera Lens Filter

JoostGT3 · May 30, 2017

ND = Neutral Density
UV = Ultra Violet
CP = Circular Polarizing

Neutral density filters are used to limit the amount of light that enters the camera. They are named Neutral Density since they should not have an influence on the color temperature. They are used when the camera is unable to reduce the aperture/shutter time/ISO sensitivity in order to avoid overexposure.

UV filters are used to filter UV light from the light entering the camera. This should result in more vivid colors. They are not really necessary, as (almost) the same effect can be reached in post processing, but it can be nice to not always have to post-process your footage.

(Circular) Polarizing filters are used to reduce the amount of reflection, especially from water or foliage. It should result in more vivid footage, with the downside that they are highly dependent on their orientation wrt the entering light. That is, you should rotate the filter in such a way that the effect is to your liking, with the downside that if you do it wrong, you might get heavy vignetting, dark areas in your film, etc.