Most landscape photographers consider a circular polarizer to be an indispensable tool for darkening skies, removing reflections from water, removing glare from foliage and enhancing the saturation of colors. I always carry a circular polarizer with me and use if quite often when shooting landscapes.
Recently, I participated in a macro photography workshop in the Adirondack Mountains with Steve Gettle. One of the things that I learned is how useful a circular polarizer can be when capturing macro images of foliage. The polarizer helps to remove the sheen from the leaves which deepens the contrast and color.
Nearly all of my lenses have a 77mm filter thread. Given the expense of a circular polarizer, I keep just one in my bag and transfer it from one lens to another as needed. The problem that I faced during the workshop is that my 105VR macro lens has a 62mm filter thread. So, for the time being I had to manually hold the filter over the lens--which is far from ideal.
I was faced with two choices to solve the problem. I could purchase a circular polarizer with a 62mm filter thread for my macro lens at a cost exceeding $100. Or, I could buy a 62-77mm step up ring to enable me to use my 77mm filter with my 105VR lens. I opted to go with the step up ring, but ordered it through eBay for less than $5.
Here's one of the images that I captured from the workshop using the 105VR with a circular polarizer. Next time, I'll have to remember to keep the photograph without the filter--as the difference in contrast and color is quite significant.
Fern on bark