I realized that CPL ( circular polariser ) is becoming very effective during the year end period. I have been playing around with my CPL most of the time, and have not seen my CPL able to darken the sky so much.
I took this shot at about 11am today ( bright day light ).
NOTE: NO color correction / sharpening was applied.
canon 1D, 17-35mm lens.
F16, 1/60 sec.