Polarizer Question

The first time I used my CP on my 10-22 I noticed the uneven coloration of the sky and later read where that is a common problem with a WA lens. Is there specific angle of view where the problem begins? Do I need to just experiment to see when it begins to occur or is there a rule of thumb about how wide you can go before you begin to see the uneven colors? Does this problem have to do with the angle of the sun in relation to the subject, or possibly the brightness of the sky, or is it solely due to the angle of view of the lens?

This is one of the limitations of CPLs and there is little you can do to avoid the problem when using UWA lenses. However, a graduated ND filter can give you much the same effect by darkening the sky and it will do so evenly.

Using the "slim" or "thin" sized filters will help. I've been able to get images that don't show the uneven coloration that you mention with my 10-22mm at most places in the zoom range. Sometimes moving around and/or turning the adjustment ring will tame the beast

seaside wrote in post #5879937
Using the "slim" or "thin" sized filters will help. ...

I think that there are two things going on. Using a slim or high quality CPL will address the vignetting problem one gets in the corners but not the brightness change across the sky.

^ Correct; two different issues.

Sparky98 wrote in post #5879832
The first time I used my CP on my 10-22 I noticed the uneven coloration of the sky and later read where that is a common problem with a WA lens. Is there specific angle of view where the problem begins? Do I need to just experiment to see when it begins to occur or is there a rule of thumb about how wide you can go before you begin to see the uneven colors? Does this problem have to do with the angle of the sun in relation to the subject, or possibly the brightness of the sky, or is it solely due to the angle of view of the lens?

CPLs work best at a 90 degree angle to the sun.

With UWA lenses you are taking in so much sky that you are seeing those areas that are much less than 90 degrees angle off so they aren't as affected by polarization.