Circular Polarizer with 12-24 for landscapes

I'm getting a Tokina 12-24 that I'll be using for landscape work on my Nikon

D200 and will be using a circular polarizer. I know that to avoid vignetting,

Tiffen, Hoya, etc. make special thin versions. But has anybody tried the Cokin

P series circular polarizer on a 12-24? Is the P mount big enough to keep it

from vignetting even though the whole think is clearly not thin? I already have

the P series system (along with an ND grad) and the ciruclar polarize for it is

half the cost of a 77mm circular polarizer. For landscapes, I want to get in

everything the lens can see and not have to crop because of vignetting. (Going

to the Grand Canyon South Rim for the first time next week.)

If you use a Cokin P wide-angle filter holder (or cut the first two slots off of a standard

holder), you should be able to use the polarizer down to at least 14mm before you get

vignetting. Using the standard P holder you'll probably start getting vignetting around

16mm. That said, you may not want to plan to use a polarizer at the widest settings of

your lens. You won't get uniform polarization across the field of view.

I can get away with shooting at 12 with a slim polerizer on the 12-24, however, i cant get get away with the polerization issues when shooting wide. Therefore, I almost never use a polerizer on that lens. . .

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00JJb4

I would NOT use a polarizer on a wide lens when including the sky; the blue of the sky will

not be uniform, and it generally looks terrible (at least to my eyes). I would use a polarizer

on a wide lens only when the sky is not included, such as the interior of a forest, where it

does a great job.

Have to agree with Stephen's caution about using a polarizer on a very wide lens -- you will

definitely get a gradation in sky colors. Whether you like it or not is a personal preference.

Some times, you get luck but most times, the distinct and abrupt change in the sky is pretty clear due to the CP ... like in this one ...

 

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<img src="http://d6d2h4gfvy8t8.cloudfront.net/4004719-md.jpg">

The reason for the uneven pola effect is that the filter works best at 90` angles to the sun. And it works less at shorter angles. WA lenses often have wider than 90` fields of view.

Are the polarization problems (not vignetting problems) with a lens this wide specific to circular polarizers or are the a problem with linear polarizers as well? My understanding is that linear polarizers don't work well with autofocus but I've been manually focusing for 30 years so that's not an issue if they work otherwise.

In terms of creating the polarization effect, linear and circular polarizers work the same way,

so they exhibit the same problem with wide angle lenses. Also, using a linear polarizer with a

modern SLR will affect your metering as well as AF.

Cokin P series wont work well to the widest part of the lens. Try thin polarizer filters - even then, you have to make sure that it's the only filter on the lens. If shooting scene w/o sky, slight vignetting is not a problem - you can always use PS to clone out. For sky, the gradation of color is the problem - but sometimes that do add effect - again can be fixed/touched up in PS

Just an idea....how about using a 'bluehancer' filter? I never used though..so far I only used a redhancer

-SR