The Truth About UV Filters
UV filters have become a must have item for many photographers who want to protect the front of their lens. They serve as cannon fodder (or as I like to call it “Canon” fodder), shielding your expensive lens from dangerous elements that might scratch it. It makes perfect sense to use a $20 filter to protect your $500+ lens. A filter can be cheaply and easily replaced, where a lens is much less expendable. At least, that’s the justification that camera shops will give you for purchasing one of their UV filters.
The reality is that most well built camera lenses are actually quite tough, especially on the front element. Don’t believe me? Watch the video below.
It’s hard not to cringe when you see that hammer come out, but surprisingly the Canon 50mm takes a beating without showing any signs of damage until the end of the video when the hammer is reversed. It’s not that a Canon lens will never show signs of damage from a fall, but it would probably have to be caused by extraordinary circumstances. It’s probably more likely that the non-glass portion of the lens will break before the front element is noticeably damaged.
What’s the harm in using a UV filter? Well to use an analogy it’s like putting a suit of armor on an olympic runner. Yes you are protecting him from scraping his knee, but you will be hurting his performance. In most cases you are adding an inferior layer of glass in front of your lens. Cheaper filters may reduce contrast, create additional lens flare, or just have a bad build quality. That extra couple centimeters added to your lens barrel may also create a slight vignette in the corners of your image.
If you are still shooting with a film camera, you may actually want to continue using a UV filter to improve contrast on hazy days. Digital sensors aren’t nearly as sensitive to UV light as film, so if you are shooting digital there’s really no discernible reason to use these filters for that purpose alone.
UV filters are still useful if you are for example shooting in a heavy mist or dust. Other than that, I see no reason to recommend a UV filter. For the purposes of protecting your lens, you should make sure to use your lens hood at all times and lens cap when the camera is not immediately being used..