Filters - to use or not to use ...

[Mad Aussie]

... that is the question

Heard a few opinions lately about this and some comments in the threads here got me thinking it might be interesting to see what people think.

I'm talking about the UV, Haze or Skylight filters that many people (including me) use as a protection for the front of their lens.

UV filters are designed to filter out the harmful UV rays that can damage the lens or sensor over time right?
But these days of digital our lens glass has coatings that does that and our sensor has layers of fine glass over it including one that is a UV filter.

So in terms of UV protection, we don't really need to add a filter for this purpose do we?

The Skylight filter (same as a Haze filter???) is designed to filter out the haze and clarify the photo. Damned if I've ever seen it noticeably do that?
Far as I know (which could be limited) the better lenses (possibly cheaper ones also) have coatings on their front elements that do this job also.

So again, I wonder do we really need them?

Are they just a great 'sell up' item every time we buy a lens?

Another view I heard recently was that lens manufacturers spent a great deal of time, money, effort and expertise to create lenses capable of high quality images ... then we stick a $30 - $60 piece of glass in front of it.
We are led to believe these increase or 'protect' the image by not allowing unwanted light sources through into the lens. I'd think my AU$2000 lens with it's expensive coatings would do a better job than a AU$65 filter. Maybe not?

I know when shooting mountain bike races at night I need to remove the filters from some lenses in order to avoid unwanted flares and light artifacts. My cheap little 50mm 1.8 is particularly bad for that.

So in terms of protection then we still use these filters to stop any impact on the front of the lens or any scratches that might develop. How necessary is this I wonder too?
If I have a lens hood on, and usually do, then it's unlikely I'll get anything to actually impact the front element. I guess the possibility is also there, however rare it might be.
If we do get small scratches on the front element then it's highly unlikely they'd show in a photo anyway due to the lens focusing well past that point. A bad scratch might reduce the contrast in that area of the image though. Something we could fix in PP or spent a few hundred dollars having a new element put in the event it was bad enough.

So, what are peoples thoughts here? Is there good reason to use these filters or is the only value that of protection against scratches that are unlikely to occur anyhow? Still might enough reason to use them though. And if we do, are we likely to be lessening our image quality on better lenses at least?

[Marko]

So, what are peoples thoughts here? Is there good reason to use these filters or is the only value that of protection against scratches that are unlikely to occur anyhow? Still might enough reason to use them though. And if we do, are we likely to be lessening our image quality on better lenses at least?

It's really quite an interesting point actually and at the end of the day I too am guilty of using a filter to protect the lens. But protect it from what? Surely it's not making my lens 'better'. Likely it's making my lens worse even if it's only to the minutest degree....and lenses are meant to be 'used' not protected.

At the end of the day i think it's to protect its RESALE value. A pristine looking lens is simply worth more.

[Greg_Nuspel]

I always say they are for protection of the front element, scratching, water, sneezes, etc. I have seen the results of a tripod head meeting the front element of a 300mm 2.8 not pretty the lens then had some flare issues. UV nah, klutz yeah.

[AntZ]

An interesting question.

I know I am much more comfortable giving my filter a clean if I think I see a spec or smudge on it. I am much more reluctant to give my front element a clean unless it really needs it.

I actually gave this a test a couple of afternoons ago when I was taking a photo toward the late afternoon sun and getting bad lens flare. I tried removing the filter and was no better. To some extent that makes me feel less worried about the impact of a filter on lens flare. I have a mid level hoya filter.

I'm quite carefully with my gear, but still have some marks on the filter. Eventhough it doesnt show in any images, it makes me happy I had a filter on the lens or the marks might be on the front element.

[Matthew]

Great question and worth some consideration. I do recall that the “haze” filters had some discernable effect when shooting B&W landscapes on sunny days – I’ve never heard of UV filters actually protecting the mechanics of a camera over the long run.
I have low-end UV filters on all my lenses which promptly come off once I have composed my scene. More easily done for me as I almost always use a tripod. Polarizers, on the other hand...
I simply cannot see that the image through a good quality will benefit from even a multi coated Hoya or B+W filter. I bet if you went to their web sites you would find “data” to the contrary mind you. I do like the protecting affect that the filters have on finger prints, sneezes and the like. The less I ever touch the front element with anything, the better.

Cheers

[F8&Bthere]

yeah this one is the subject of many a forum debate. I figure that people aren't buying these for UV filtration or haze reduction, only for protection, and it's partly paranoia but partly sensibility. Every time it comes up in a photo forum you get those that give the "I'm not putting a $60 piece of glass over my $2000 finely tuned optic" and those that say "I'd rather replace or clean a $60 filter than risk damaging my $2000 optic". But I think it comes down to this, at least for me: If you're going to use a filter for protection, #1- get a good one- make sure it's high quality multicoated, #2- don't buy it at the camera shop because they mark them up like crazy- you can get the exact same thing off ebay for half the price, and #3- take it off in situations where it may cause problems- like shooting into strong sunlight, or at night with strong light sources, etc

On point #2, maybe I'm just the world's worst negotiator, but it absolutely floors me that every time I buy a lens at a camera store, that they offer me the filter, but won't discount it for me. My God, I just bought a $1000 lens from you and they sell the same damn filter on line for less than 1/2 the price, you think you could just knock a bit off your outrageous mark up and get rid of some of that moldy old inventory!

[Mad Aussie]

Interesting to hear that this subject comes up in other forums often. Seeing this is the only forum I visit I'm quite ignorant in what topics get discussed elsewhere.

So far I use the filters but they are first thing to off if I see unwanted light artifacts showings when I chimp the shots. So far it's mostly been at night when lights are shining right at me.

Also, when shooting events such as mountain biking that kicks up a bit of dust, I can see value in a filter. I guess the same might apply seaside when wind might put salt on the front element.

[Greg_Nuspel]

OK you guys win just shot a series of shots at a small aperture and there was the dust on my filter

[F8&Bthere]

I know this thread is already a bit old and abandoned, but just in case anybody checks in, I found this article very helpful, with many interesting links to actual tests provided, regarding my own to filter or not to filter (for protection) decision:
http://photography-on-the.net/forum/...97&postcount=1

BTW, I decided a while back to not bother buying protective filters for my cheaper lenses, but to buy high quality multicoated filters for my more expensive lenses but to take them off as needed for certain types of shots like night/bright lights/high key. And I mostly go with Hoya/Kenko Super HMC or PRO 1 Digital off ebay from various vendors for around US$30 -$50 incl delivery for most normal thread sizes from 52mm to 82mm. I hear the B+W are easier to clean, but for the price difference some tests show they are not any superior optically to the higher end Hoyas.

[Mad Aussie]

Interesting article. Speaks volumes in the first few paragraphs then gets more technical.