Monday, September 6, 2010
Use A Polarizer All The Time—09/06/10
Should you really put this filter on your lens permanently?
The main reason these scenes looked so great was because I was looking through polarized glass, eliminating glare and making color and contrast look their absolute best. I decided then and there that maybe, just maybe, a case could be made for never removing the polarizer filter from your lens. Here are four reasons to keep a polarizer on your lens at all times, plus a fifth suggestion—all the reasons not to.
1. Lens protection. Many photographers sport a UV filter at all times specifically to protect their expensive lenses. Besides, they say, it has almost no effect on the picture quality. Well, if you’re going to filter your photos all the time, why not choose a filter that has a hugely beneficial effect on your pictures? Why not consider a polarizer for protection and for fighting glare?
3. Compensation is automatic. Have you ever been shooting in manual mode and then put a polarizer on your lens, only to discover after several shots that you’re underexposing dramatically? If you’re shooting in Program mode with a circular polarizer, the exposure compensation is handled automatically. But manual shooters have to open up (usually two stops) when you put a polarizer on your lens. If you keep that polarizer on the camera all the time you'll never forget to compensate since the filter is already there and you’re already in the habit of adjusting with every exposure.
5. There are some real downsides to keeping a polarizer on your lens all the time, so before you run out and glue your polarizer to your camera, consider the opposing point of view: why you should not keep a polarizer on your lens at all times. First, you lose two stops of available light with every shot. That means it’s harder to open up, harder to shoot fast shutter speeds and harder to handhold the camera in low light. Unless you’re an all-auto shooter, you have to factor in the compensation with every exposure too—meaning if you make a meter reading and forget to adjust, you’ll underexpose dramatically. If you change lenses you have to change polarizers too, unless of course you cover every lens with a filter. And finally, not all reflections are bad. Some scenes really need their reflections to help provide visual cues regarding surface shape and texture. Eliminating reflections in every exposure can sometimes be a detriment.
In the end, perhaps the best policy is to never remove a polarizing filter from your camera bag. Make sure you carry a polarizing filter whenever you carry a camera, and you’ll never be unprepared to take advantage of its many tremendous benefits.