donrent Loc: Punta Gorda , Fl

Does a CPL work the same on snow as it does with clouds ?
I have NO expectations of being in snow again , but just wondering.

jerryc41 Loc: Catskill Mts of NY

From what I've read, Yes.

http://photo.net/canon-eos-digital-camera-forum/00VBTm

RWR Loc: La Mesa, CA

Polarizers block polarized light, regardless of the source.

rook2c4 Loc: Philadelphia, PA USA

I've used the CPL successfully on snow. Particularly on bright sunny days.

Bugfan Loc: Toronto, Canada

Hmmm, I don't quite agree with the above, though perhaps this is a semantic argument.

The purpose of a polarizer is to reject light that's streaming into the lens from an angle thereby creating the potential for flair. It's intended to block light that is approaching the lens from random angles like the sparkles on the water from the sun. And it's for getting rid of light that is reflecting off glass and other surfaces.

Basically its intent is to allow only that light that enters the lens perpendicular to the lens surface.

The light that reaches the lens surface as a result of the polarizer doing its job is called polarized light. If the light were polarized in the first place you would not need a polarizer at all. It's because the direction of light tends to be scattered and random that we need a polarizer.

To give you a formal definition ...

"Polarized light waves are light waves in which the vibrations occur in a single plane. The process of transforming unpolarized light into polarized light is known as polarization."

It's because the light is scattered in all kinds of different angles which tend to result in flair, reflections and other issues, that you want to use the polarizer. And you use it so that the light entering the lens is straightened out to enter the lens in a single plane.

RWR Loc: La Mesa, CA

I have no desire for an argument of any kind! Non-polarized light will freely pass through a polarizing filter. I'm sure a Google search can confirm this.

Bugfan Loc: Toronto, Canada

As I said we may just be having a semantic argument. I too don't want to belabour the point.

http://www.cambridgeincolour.com/tutorials/polarizing-filters.htm

https://en.wikipedia.org/wiki/Polarizing_filter_(photography)

Some authorities talk about some angles of incoming light as being polarized and others talk about it as not being polarized. Both in the end accept that when it cones out at the end it is polarized. I guess it boils down to how you want to describe it and that's why I'm not going to comment any further.

It's like math, I learned the old math, the kids today learn the new math. Both get to the right answer just through different paths. Both are right too. So let's leave it at that.

RWR Loc: La Mesa, CA

Well, I had thought I was done, but " ... when it comes out at the end it is polarized" is too misleading for me to let go. A polarizing filter does not convert non-polarized light to polarized light.
Robb Smith writes in the Tiffen Practical Filter Manual:
"A polarizing filter acts as a microscopic grid, or gate, that automatically passes light that is not polarized. Light that is already polarized will either be stopped or passed, depending on how the filter is turned. When the grid of the filter is turned crossways to the direction of vibration of polarized light, the light is blocked. When the grid is aligned with the direction of vibration, the light will pass. By turning the filter, you can regulate the amount of polarized light that will pass through. Ordinarily, non-polarized light will pass the filter regardless of the angle at which it is turned. Because average scenes will contain mostly non-polarized light, the polarized light held back by the filter is ordinarily unwanted."
I shall now shut up! :)

Pablo8 Loc: Nottingham UK.

A polar' filter will effectively control the reflected light from the surface of snow, if the angle of the surface is approximately 30 degrees to the shooting angle of the camera. The same criterea applies to wet pavements / shop windows / rivers / the sea etc. Easy to check out the effect, without having to take a picture. If looking through the filter unattached from the camera, make sure you are holding the filter the same way the camera lens will be seeing( male thread towards the eye), then rotate the filter to see what effect is possible. It's not rocket science.

blackest Loc: Ireland

CPL is pretty good at toning down reflections from shiny surfaces. Last time I used one was for a car, which made the black paint, blacker on the car sides anyway, the bonnet/hood still reflected the sky as the angle was different.

GENorkus Loc: Washington Twp, Michigan

Yes. On a clear mid day on a lake you might also want to have an ND filter as well. Just looking through your camera will be blinding. You probably will need sunglasses too.

One more thing. Make sure your screen is as bright as it can be and plan to shadow the LCD to view it as well.

Manny Jay Loc: Colorado

RWR:
Your quotein the Tiffen Practical Filter Manual contradicts itself! I believe that the word "not" doesn't belong therek, but what do I know. Think about it!

"Well, I had thought I was done, but " ... when it comes out at the end it is polarized" is too misleading for me to let go. A polarizing filter does not convert non-polarized light to polarized light.
Robb Smith writes in the Tiffen Practical Filter Manual:
"A polarizing filter acts as a microscopic grid, or gate, that automatically passes light that is not polarized."

SharpShooter Loc: NorCal

I not so sure that Don is asking about Polarized Light as such. Don needs to come in and clarify.
Don asked about the effect of a cpl on clouds, which is to darken and enhance the clouds and at the same time make the sky a darker shade of blue! From that statement I'm not sure WHAT exactly he is asking as it relates to snow.
No matter how we define it, I think we all know what a cpl does to reflective glare on water, no mater what is actually happening scientifically or semantically!!!
We need clarification from Don in order to answer his question correctly.
We all know how to use Google and I'm not so sure this answer is there! Just saying. ;-)
SS

Spirit Vision Photography Loc: Behind a Camera.

They block polarized light from non-metallic surfaces.

Leitz Loc: Solms

Yes.