Just to redress the balance of the party political broadcast on behalf of the anti-filter party (AFP)
, this topic has been discussed to death on this forum. Just do a quick search and read some of the later threads that include a comparison test between different UV filters. Basically, you'd be hard put to tell the difference between using a high quality (not a cheap!) UV filter and a naked lens in average/normal lighting conditions. The exceptions to this can include shooting straight into the sun (or other strong light source) to try to generate lens flare (as most of the filter review tests seem to do), or when photographing the Aurora Borealis where the use of a UV filter can produce a Newton's rings type effect on the image due to the frequency of the light waves.
The rest of the time using a high quality UV filter (
if that's what
you want to do) is probably not going to have a discernible/significant adverse effect on image quality. Before the AFP start shouting 'Fake news', how clean is your front lens element? Any haze on it will result in a degradation of image quality, so unless it's spotlessly clean (and kept that way) then you could be in the same place as using a UV filter! Some high quality modern UV filters come with 'repellent' coatings, which makes them easier to keep clean than the front element of some lenses, and accidentally putting some cleaning swirls or scratches on a filter will probably cost you about £60 or so to replace the filter. How much does it cost to replace a front lens element, and how long would you be without your lens while this is being done?
Before any members of the AFP start saying that it doesn't matter about scratches on the front element, and producing 'test' results to show this, I have two questions: If it doesn't matter if the front element is scratched, hazy or dirty because it has an allegedly negligible effect on image quality, then why should putting a high quality, multi-coated, piece of glass a few millimetres in front of the front element matter so much? Secondly, have you seen 'tests' on dirty/scratched/broken front lens elements that include shots taken straight into the sun or a strong light source (like the test reviews on UV filters seem to do)?
The few that do tend to show that having a hazy or swirl scratched front element is likely to produce the same effects of veiling lens flare as a cheap UV filter (or much worse in the example of a badly scratched or broken front element)... and, guess what, if shooting into the sun I can take the UV filter off and use the spotlessly clean front lens element beneath it for that particular shot!
I use UV filters on my lenses for a few reason; I use my lenses on film SLRs as well as DSLRs; the Canon L lenses I use require a filter to achieve full weather resistance; I find modern high-quality UV filters easier and less stressful to clean than the front element of an expensive lens; it may provide a degree of protection if the lens is dropped or hit by a flying object; it keeps the front lens element spotlessly clean and if I do find myself shooting into the sun or other such situation where using a UV filter may cause a noticeable degradation of image quality then I can take it off for that shot and replace it afterwards.
It's down to personal choice, if you don't like UV or other such filters then don't use them, it's as simple as that.
