loubrown Loc: Edmond, OK

I have a CPL on my Nikkor VR 55-200mm lens. Can it be left on all the time without causing problems?

BigD Loc: The LEFT Coast

In short, no. A CPL is designed to channel light in a single direction in order to enhance saturation and reduce reflections. It can make skies bluer and clouds deeper in contrast and it can remove the shimmer from water but it costs you some light to do it. The effect is not always a good one such as when taking indoor shots with a flash where there is already very low contrast. You can loose detail with a CPL in low light conditions. In general they are used for outdoor scenes with plenty of ambient light of course there are always exceptions to every rule. A stay on all the time filter would (arguably) be a UV/Haze filter.

loubrown Loc: Edmond, OK

Thanks, BigD

abc1234 Loc: Elk Grove Village, Illinois

Use it only when it works. Keeping it on all the time will cost you two or three stops in exposure. That can be the difference in having unbecoming camera or subject movement.