The polarizer - which attaches to the front of the lens - has long been known for its ability to deepen a pale blue sky. But a polarizer can do so much more than that. Most important, the circular polarizer can help tone down reflective surfaces (such as glass, water, wet rocks, foliage, and painted objects) in order to reduce the glare and, therefore, enhance a scene's natural colors.
Many outdoor photographers use the polarizer when itís overcast or just after a rain. Soft light is perfect for shooting water - waterfalls, streams, wet streets, etc. - and often a polarizer will give those images a boost by reducing the glare and bringing out the colors.
The polarizer also will cut the surface reflection and let you see into small ponds, shallow streams, or tide pools. But beware, since that ďsurface reflectionĒ may be what attracted you to the scene in the first place!
Important: Don't Forget to Turn It! The polarizing filter turns in its mount, and you must rotate the outer ring to see the possible effects. Then, when you hit the amount of polarization that you want, you shoot the scene at that precise orientation. If you do not see any effect whatsoever as you rotate the polarizer, itís very likely that the scene is not a "polarizer scene" -- i.e., youíre not at an angle to the sun or the surface isnít actually reflective.
-- It is at its peak effectiveness when used at a 90-degree angle to the light source - say, with the sun at your right or left.
-- Donít bother trying a polarizer when you are facing the sun, or if the sun is at your back. There will be no effect.
-- Due to the 90-degree factor, beware when using a polarizer with a wide-angle lens to enliven a blue sky, since it could cause an unnatural and uneven variation from dark to light.
-- As for reflective surfaces, sunny or cloudy, if the subject you wish to polarize consists of different angles, then not all surfaces can be polarized at the same time. So just turn the ring and see what looks good to you.
Photo Examples Ö Old Detour Sign: Check out the dramatic difference that the polarizer made on this Detour sign. But also check out how much bolder the red and yellow are on the frame underneath the sign. At the same time, the old truck at the top background is at a different angle to the polarizer than the Detour sign and, as a result, there was no effect. Just to confirm: The richer color in parts of the After image resulted entirely from the polarization. In addition, the lighting for both images was nice and soft from overcast.
Note: Not sure what your lens's filter size is? If you are already using a protective filter on your lens, then thatís the thread size for all filters (including polarizer) for that lens. Otherwise, youíll likely find the size on the reverse (inside) of the lens cap, or along the rim of the front lens element. Or look for it on the lensís barrel (itís the number following a circle with a line through it).
NOTE: This article is adapted from The BetterPhoto Guide to Photographing Light
About Author / Instructor / Photographer, Kerry Drager