Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

Light rays bend, that is a principle of optics, thus the light rays bend around the scratch. As I alluded to before, look at mirror lenses with the huge chunk of plastic in the middle of the lens. It really has little effect on the resultant image. Research physics laws for more info here. In old days, we used India ink on scratches to lessen any contrast issues that might have induced by the scratch.

Rick from NY Loc: Sarasota FL

Lord no - NOT AGAIN!

Yes - you must use a protection filter. It has no effect on the image.

No - Don't dare use a protection filter. It will degrade the image.

Pick the answer you like best, stop reading the same garbage repeated ad nauseum every time this question is asked and go shoot something. (photographically that is).

bleirer

That was a great article that might have changed my mind. For $50 bucks I can get a clear cover with 99.7% transmission? What's not to like?

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

It's not so much image degradation as it is how good the protection offered is. I do agree that it is a personal choice though. To each their own.

amfoto1 Loc: San Jose, Calif. USA

Watch this and decide for yourself:

https://www.youtube.com/watch?v=P0CLPTd6Bds

In general, a "protection" filter is a waste of money, IMO. Very rarely necessary and it's very unlikely that some thin piece of glass would offer much protection in many situations. Use the hood and cap that came with your lens. They do a much better job protecting it!

I actually have several sizes of high quality, multi-coated UV filters in my camera bag, ready to install and use on the very rare occasion when I'm out shooting in a sand storm or photographing at the beach where there's salt spray in the air... or in a few other situations where those filters might actually serve a purpose. I already had most of those UV filters, from shooting film that was overly sensitive to UV light. But that's not an issue now, shooting digital (which has built-in filtration for UV), so now those are among my least-used photo accessories.

A quality, multi-coated Circular Polarizer is a MUCH more useful filter (but even that should not be left on a lens all the time).



Well, I really didn't like the having to spend many hours fixing 1200 images shot by a second shooter I'd hired, who ignored my request that he remove the "protection" filters from his lenses. Part of the "99.7% transmission" through his filters caused an ugly greenish tint, veiling and ghost flares in most of his images!

juanbalv Loc: Los Angeles / Hawthorne

ha.

canon Lee

Hi Hank. In the past, these filters were used to block UV from hitting the film. All digital camera sensors have a UV/IR filter in front of the sensor, so there is no more need to use UV filters! On the minus side of the filters, they can reduce the image quality, especially if you use low-quality ones.
UV filters are a carry over from the film days, where its affects warranted filters. Manufactures make money selling UV filters. Now a ND filter or Polarizing filter do have their uses and are very affective.
If you however are shooting outdoors, lets say on a windy beach, then use a UV filter to protect your expensive lens, as a hood will not do the job of protecting scratches.

RichardSM Loc: Back in Texas

PHRubin Loc: Nashville TN USA

After 40 years of having a filter for every lens I realized I never "broke" or scratched one. Every lens I have now has a hood, but no filter. Protection without affecting the image.

Rick from NY Loc: Sarasota FL

My reply was meant to be ironic. Who cares for the reason - few of the replies are scientific (just someone's opinion) and those that do offer "scientific" proof of the writer's opinion are all but meaningless because -

as far as the image - the end use for most photographers does not include 200% pixel peeping.

as far as protection - it is virtually impossible to recreate identical tests of "protection" in a lab. The gear never hits the ground, gets poked, gets splashed,
gets otherwise scratched, yadda yadda yadda, the same way twice.

This entire argument is just silly. Pick your choice and stop obsessing about it. The people who reply to the question every time it is raised and fill pages and pages are more interested in convincing everyone that only they have the right answer. Nonsense.

redlegfrog

One thing I haven't seen in the discussion of filters is dust control.

Some time ago I decided to forgo the protective lens because I wanted the sharpest image I could get. I noticed right away that every time I took My lens cap off there was dust on the lens that needed cleaning. That was a lot of cleaning and I began to worry what all that cleaning was doing to the front of the lens.

Now I have decided to keep on my lens a junk filter and a lens cap and when its time to shoot I just unscrew the cap and filter together. My lens stays very clean and I think I have the best of both worlds.

leftj Loc: Texas

Dust control has been mentioned many times.

amfoto1 Loc: San Jose, Calif. USA

Again, watch this video: https://www.youtube.com/watch?v=P0CLPTd6Bds

Someone actually HAS done some testing... with some interesting results.

lamontcranston

Sold by B&H Photo. Made in Germany of high-grade German optical glass with brass threads to prevent seizing up, and reasonably priced. If I can't find the filter I like made by B&W I buy Hoya.

Tomcat5133 Loc: Gladwyne PA

Well I try and buy the best UV filter I can. I do believe that some filters are superior. ND's are is good bad and the ugly.
That said I am very careful with my photo and video equipment. Have never broken a lens. But a couple years ago I put my Sony 70 200 on a couch next to me
while filling a case and it rolled off onto a tile floor. Stupid on my part. I usually do this where there is a rug and one moment of stupidity. The UV filter was smashed and the lens after I extracted the filter was fine. I did find with theses smaller hybrid cameras like the a6300 and the a7 series it is harder to hold on.
I had my a6300 in a very small case this past summer and saw a shot. the lens was the zeiss 16 70 a very nice lens. I opened the mini case
and it dumped the camera onto the ground. The filter was scrapped on the mounting but fine. The lens needed a little work and it was fine. Whew.
Get a good UV filter if you have expensive lens. And the lens hood has probably saved a lot of good lens.