Old farm- 2013-02-02 at 13-12-06

Notice the different blue hues in the sky? I'm using a Tiffen circular

polarizer and I turn it until the sky looks the deepest blue but I don't like

the way the shy has different shades. Is this because of an inexpensive

filter? or just nature of the beast or operator error?

Kyle,

Light from the sky is polarized in different amounts from different directions, based on the angle from the sun.  See http://en.wikipedia.org/wiki/Rayleigh_sky_model.  I assume you are seeing this variation when you use a polarizer.  The variation across your photos is generally going to be greater with wide-angle shots.

You will find that this patchy colour variation phononema occurs when there is a plain blue sky and is almost impossible to remove, for this reason I don't use a polarisor in these conditions.  The make of polarisor or how you are using it has little or no influence on the outcome.

Kind Regards

Alf

Polarisers boost some colours and sometimes really "make" the photo, especially with certain types of cloud formations (see for example 'Qinghai' in 'Landscape' folder in my portfolio). But they can be tricky if used with a wide angle lense for the reason you mention. In my experience it is impossible to correct the problem in Photoshop without creating massive artefacts. When shooting a great scenery I always take shots with and without the polariser. And I tried to avoid using it with a wide angle lense.

Hope this helps.

Best regards,

Alain

I, too, never use a polarizer on a wide-angle lens except when I'm wanting to reduce reflection glare off vegetation in a forest.  I would never use it on a wide area of plain blue sky because of this kind of variation in the depth of the blue (trust me, I've seen much worse).  Even with a normal lens, care must be taken with a polarizer and blue sky.  Only with a telephoto with it's reduced angle of view can you start to relax a bit and let a polarizer do its work.  Be careful at high altitudes -- a polarizer can make the sky go nearly black (or maybe you want that effect....some do).  It's a filter that takes some practice to know its strengths and weaknesses.