Are any of you using polarizing filters?

It seems a lot of HDR could be avoided with a polarizing filter.

Excuse me if this question/comment seems noobish, but I just learned (in the last couple days) what a polarizing filter is and what it does. I've also researched the better brands, and it appears that for roughly a hundred bucks you can get a good one that will get you really good color saturation and very blue, natural-looking skies.

What do all of you think?

Cost is going to depend on size. I use B & W Multi-Coated Kaesemann CPLs. A 72mm one is about $170.

As far as "a lot of HDR could be avoided with a polarizing filter": you may be confusing HDR with how HDR can be processed to have certain look that may seem like a CPL has been used.

Well, what I mean is that the polarizing filter can help to keep from skies blowing out.

I realize HDR is meant to capture images that are impossible otherwise. However, sometimes I do simply two exposures in order to get the sky bluer and more natural.

I recently got a CPL and really enjoy it. It costs about 2 stops of light (or more). I haven't found that it helps with blowing out skies but my experience is limited.

A set of Graduated Neutral Density filters are probably what you're looking for if sky blowouts are the main issue.

MikeFairbanks wrote in post #10981089
Well, what I mean is that the polarizing filter can help to keep from skies blowing out.
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Ah, I see. I wasn't sure by your phrasing, how you were interpreting HDR.

A CPL filters the entire scene so whatever light it "holds back" in the sky is also being held back everywhere else.

Grad NDs are the correct tool for cutting light in only part of the frame.

Mike - Your comment that a CPL will keep skies from blowing out bothers me. It won't. Remember, the filter only pulls the blue sky darker, not the clouds. It makes the clouds stand out more from the sky, giving higher contrast...and it only works deepest at 90 degrees from the sun.

I used to use a polar on lots of things when I shot slides in the 70s, but got away from it eventually. Lots of people don't like the effect, and I always wanted more light due to the 2 stop loss.

Perhaps the GND is what you are really wanting. With that, you can darken the upper (or other area) of the of shot and allow normal light other places.

The polar filter works poorly with a wide angle lens, because you can readily see the light to dark graduation from the 90 degree point, to non-90 degree points in the sky. Again, the most effect is 90 degrees to the sun. Ever wear polarized sun glasses?

CPL is for controlling polarized light. This can be in the form of reflections off of non-metallic surfaces (like big glass storefront windows or reflections or glare coming off of the surface of water) or for deepening parts of the blue sky - but as Gary points out, its effect is variable across the frame, depending upon the angle of the sun to your camera.

Neutral Density (ND) filters are available in various levels of light attenuation and stop down the light entering the camera, without introducing color shifts. These filters permit the user to shoot in bright conditions at slow shutter speeds - for example, you want that soft silky flowing water effect that takes 1/8 to 1/4 sec but you cannot shoot it in bright light because even at f/22 and ISO50 the shot is still blown by 3 stops? Use a ND filter that gives you 3 stops of light attenuation and there you have it!

Graduated Neutral Density filters (GND) are the same as ND filters but have the "ND" part applied to a portion of the filter. This permits the user to selectively attenuate the light in part of the scene, while letting the full amount of light through form the rest of the scene. In terms of HDR and DR compression, this is the filter that would achieve such an effect. So, if you have a super bright blue sky and your "ground" area has lower brightness details in the midtones and shadows, you could use a GND to attenuate the light in the sky (the upper half or third of the scene) and let the full amount of light through for the rest of the scene. This effectively compresses the dynamic range of the scene by locally changing exposure. It is sort of like a real-time exposure blend where you would normally take one shot for the sky and another shot for the ground and then blend the two in post. Of course, you have to choose the correct amount of light attenuation to achieve the compression you want.

I do not use any of these filters when shooting HDR. However, some applications (like Picturenaut) permit the user to enter a value for the effect of a filter so that the EXIF data are corrected to the actual exposure based on the amount of light that the particular filter is attenuating during capture.

Kirk