Do I need a filter for my prime lens in order to protect it from dust, splashes, etc?

Question

From here: http://photo.stackexchange.com/a/569/5205

UV Filters:
Many photographers feel that it is worthwhile to put a UV filter on the front of every lens, on the basis that this will protect the front lens element - from dust, scratches and catastrophic damage if the lens is dropped. In other words, it is a kind of insurance policy against lens damage. I understand that Scott Kelby takes this position.

Since prime lenses are not supposed to zoom can dust, water, etc still get inside it if I don't use a filter?

Asked by Anisha Kaul

Answer

The filter doesn't protect against dust getting "into" the lens, it just protects the front element. So the arguments for a filter are equally valid for zooms and primes.

Personally I don't use them, as they have a negative impact on image quality. Always keeping you lens hood on is another way to protect the front element.

Also, I recently damaged my lens (a prime), as I dropped it while changing lenses. Two elements fell out the back, and the focusing system got ruined, but the front element is intact. So the filter is no magical protection for your lens.

Answered by Pete

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