Pictures By Alan

In an earlier shot, I had decided to use the polarizing filter, which can turn the sky a deeper blue. Since there was a lot of snow blowing around, and it was very cold to have my gloves off, I decided to break normal practice and stack the polarizer on top of the clear filter I normally keep on the 24-105/4. This isn't normally recommended because of reflections between the filters, but it'll do in a pinch.

As might be predicted, the two filters (one from Hoya, one from B+W) quickly became stuck to each other. I have a filter wrench, but it was in the other camera bag. So the rest of the shots were taken with the polarizer, whether they needed it or not. On the wide angle shots, I found another reason not to stack filters. The black areas in the corners of this shot are the second filter rim obscuring the view of the lens.

Once we were back at the house, I located the filter wrench and managed to separate them. Lessons learned, I guess.