Filters on lenses or not?

<p>I know that most people use filters on their lenses to protect the front-most element of the lens from physical damage.<br>

Other than physical protection it seems such filters don't do much else. My questions are:<br>

Don't filters increase the risk of flaring and ghosting and is that significant for the protection they afford? They may degrade the image if lesser glass is employed, right?<br>

Modern lenses' coatings MUST absorb UV and "skylight," right? So if one will use a filter, why not a clear glass filter?<br>

And, finally, wouldn't the public be better served if lenses, both high and low end, were sold with a filter, that could be used if desired?</p>

<p> </p>

<p>I very much disagree that "most" people use filters for "protection." Very few of the more experienced people I've seen use them. And yes, I often do get ghosting and flare when I use a filter. So, I don't. I use a lens cap to protect my lens when not actively taking a photo. My lenses are perfect. BTW, there's about a hundred threads here on the topic, including one someone just stuck on here yesterday.</p>

<p>Kent in SD</p>

<p>There are lots of threads on this topic, so I'm not going to rehash all the arguments. Most people don't necessarily use filters for protection on their lenses, they use lens caps. Why include a filter with the lens, I can only think of one reason....to increase profits to the manufacturers/retailers.</p>

<p>If a particular filter works for you w/o obvious image degradation, then use one if you must.<br>

If a filter accomplishes what normally can not be accomplished w/o it, then use one.</p>

<p>As Kent pointed out, this sort of question stirs debate that is old as the hills.</p>

<p>Do filters cause ghosting and flare? Sure they do, it's the nature of optical physics.<br>

How bad it is remains a question of personal preference, quality of the filter, distance of filter to objective, shooting angles.</p>

 

<p>Some thoughts:<br /> It has been tested that depending on each situation, protection filters have an unnoticeable effect... (quality filters, I mean) or a noticeable effect, specially if they are not coated.</p>

<p>If a filter doesn`t offer any kind of filtration, the potential sales could be reduced.</p>

<p>Some lenses were sold with a filter included, like the "recent" 45P.</p>

<p>Given that many people doesn`t use them, why to add them to the package? (If so, I could have more than 30 useless "clear glass" filters... ).</p>

<p>It makes sense to use them when needed, and not to use them under certain problematic situations.</p>

<p>First I use filters on all my lens for protection I live on the coast and do many shoots sand & sea. The cost of Canon lens against the cost of a filter well no argument. I like many landscape photographers use many finters Soft Grad 1, 2. 3, Tint filters, and the one I use the most Polarizer, also a ND. You can not get the same affect in Photoshop some will tell you they can, it's just not the same. So Filters a alive a well in my camera bag.</p>

<p>Years ago I had a co-worker who had just gotten married. Sortly after his wife was unexpectedly pregnant. They were young and weren't planning to have children yet. Someone else asked him, "Don't you use birth control?" He replied that they did most of the time.</p>

<p>Using a lens cap to protect your lens falls into the same category. The main problem is that you cannot have a lens cap on when you are shooting, composing, or getting ready to shoot. However, I want to protect my lens 100% of the time; if that is not possible, as least as close to 100% as I can. "Most of the time" sometimes just doesn't cut it.</p>

<p>Just one of many iterations of this question are at (<a href="../canon-eos-digital-camera-forum/00V2wQ">link</a> ) here on this site.</p>

<p>Nothing has changed since then, or long before then. If you search for something like "filter on lens" here you will get just <em>some</em> of them.</p>

<p>The old debate again. I do use UV filters on all my lenses - and I do use lens caps as well - but as Shun pointed out - they don't do anything when you are actually shooting. In many situations, I have to go hours without the chance to put the lens cap on - I have to be ready to get the shots I want. I only use the filter because fingerprints, drops etc are a lot easier to clean of it than off the front element. In shooting situations, were the filter causes flare, I have a very simple solution - I take the filter off!</p>

<p>Shun makes the point perfectly but, if you prefer, you can instead use risk/benefit analysis for this particular niggle. How important is the possibility of damage to the outer element of your lens (benefit of filter)? How significant is the possibility of degradation/flare for the kind of shots you take (risk of filter)?<br>

 

<p>Obviously, use the best filter you can afford to minimise the "filter risk" component. Ultimately, if you're happy to repair/replace your lens if something bad does happen then, like any other form of insurance, you don't need filters.<br>

 

<p>Personally, I use Hoya Pro-1 UV(0) filters, having got into the filter habit during film days (when I sometimes used skylight 1B's in the same way as well). On the rare occasions when I buy a new lens, I fit the filter only after the new toy has been tested and then do some more test shots, before comparing the two. Maybe my eyes are giving out, or I don't know how to "see", but (except when shooting into the Sun - which I generally avoid) I have never noticed any difference (although, by the laws of physics, there must be some tiny fraction of light lost at each air/glass interface.)<br>

 

<p>Here's a rare into-the-Sun shot (on FX) with a Nikkor 28-105 AF-D @f11, using a UV(0):</p>

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</p>

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<p>Best article I know of concerning filters:</p>

<p>http://www.bythom.com/filters.htm</p>

<p>"Years ago I had a co-worker who had just gotten married. Sortly after his wife was unexpectedly pregnant. They were young and weren't planning to have children yet. Someone else asked him, "Don't you use birth control?" He replied that they did most of the time.<br>

Using a lens cap to protect your lens falls into the same category. The main problem is that you cannot have a lens cap on when you are shooting, composing, or getting ready to shoot. However, I want to protect my lens 100% of the time; if that is not possible, as least as close to 100% as I can. "Most of the time" sometimes just doesn't cut it."</p>

<p>Hey, Shun, I think this comment is worth archiving! LOL</p>

<p>John, indeed a good article by Thom.<br>

<strong><em>Thom's Maxim #19</em>: Don't put extra glass or plastic in front of your expensive, well designed glass unless you need to.</strong></p>

<p>It's so ridiculously easy for any photographer to perform definitive flare tests on their own particular camera / lens / filter combinations that I'm baffled why endless discussions / debates on this subject continue on. Perform an appropriate test, and you will have a nice quantitative, essentially un-debatable answer about the flare for that particular combo. You then have the info needed to perform a logical risk-benefit analysis as suggested above.</p>

<p>I find that the easiest way to perform such tests is to put your camera on a tripod in a darkened room, set it on manual, and put a remotely triggered flash (also set on manual) across the room, pointing straight back at the camera. Adjust the camera exposure so that no stray ambient light from the room is recorded, and adjust the flash output so that the core of the flash is anywhere from 3 to 6 stops overexposed. The more you overexpose the flash, the more sensitive the test will be to small amounts of flare.</p>

<p>The intensity and pattern of the flare you record will depend dramatically on the lens, the aperture setting, the FL (if a zoom), what type of filter you are testing, and, importantly, whether the strobe is on-axis or not, etc.</p>

<p>The following pair of images shows the results of such a test on my Nikon 28-70/2.8 @ 2.8 and 70mm, with the strobe on-axis. The upper image is without a B&W UV filter, the lower is with the filter in place. There's clearly a difference is the pattern of the flare and the level of overall veiling flare. That being said, in real-world tests, only when shooting into the sun with foreground objects in dark silhouette can I ever see a difference between filter-on and filter-off conditions for that lens / filter combo. The dark room strobe test gives you pretty much of a worst case scenario.</p>

<p>Finally, let me point out that one can't extrapolate a difference between filter-on and filter-off results with one lens to tell you how the same filter will act on a different lens. For example, just before I tested the 28-70/2.8, I tested the Nikon 105 VR. It showed almost no increase in flare when I put the same filter in front of it. A lot has to do with the exact curvature of the individual elements in each lens, which are well coated, etc.</p>

<p>HTH,</p>

<p>Tom M</p>

<p>PS - FWIW, I usually leave a protective filter on all lenses at all times, and then take an extra shot or two with it removed if the situation is likely to cause flare on a lens that I know (from the above tests) is susceptible.</p><div></div>

<p>Well, I tend to be a bumble sometimes, so unless I'm shooting into the sun I leave a clear filter on. I buy pretty expensive multi-coated filters and I've never been able to see a difference in flare or ghosting in the limited number of tests I've done. I'm sure the extra surfaces do affect the image, but I can't tell the difference for what I do.<br>

Buy one and give it a try to see for yourself. Don't scrimp on the filter cost though - buy a high end B+W or Hoya that is multi-coated.<br>

My 2 cents - John</p>

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<p>Years ago I had a co-worker who had just gotten married. Sortly after his wife was unexpectedly pregnant.</p>

</blockquote>

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<p>The main problem is that you cannot have a lens cap on when you are shooting, composing, or getting ready to shoot.</p>

</blockquote>

<p>Shun, I could not possibly have made a clearer statement for the use of filters.</p>

 

<p>Tom,<br>

 

<p>Thanks for pointing out that you need to test filters for <em>each individual lens</em> (or even every lens/body) combination, as I don't think this requirement came across very clearly in my post.<br>

 

<p>Another vote for archiving Shun's comment BTW!</p>

</p>

</p>

<p>Here's my filter story from back in the day: My friend started out in photography with a Minolta SLR. He wasn't happy with the sharpness of his pictures so he traded it in for a Nikon F. Still unsatisfied (not surprising maybe—we were all big Adams/Weston fans then), he bought himself a Hasselblad, but even it wasn't sharp enough. He then switched to a 4x5 view camera with a Schneider Symmar lens. Still, his pictures continued to disappoint.</p>

<p>He had been studying the 8x10 camera brochures for awhile when it occurred to him to try some shots without the $3, no-name skylight filter that he bought with the Minolta and had been using on all those other cameras. Eureka!</p>

<p>This is a bit off topic, but there was a kicker to that birth control story. That guy's wife was a physician. You would imagine that a doctor would know about birth control ....</p>

<p>And you would imagine that good photographers would know when to use and when to not use filters.</p>

<p>I guess it depends on how risk averse you are. </p>

<p>You ma trade quality if yo are doing risky photography. Ie., in the rain, at the sea coast, doing skateboard photography.</p>

<p>But if you are Thom Hogan, I read he used no filters in a motorbike dirt race ... with dirt splatted on his lens, he jus cleaned it up .... ;D</p>

<p>I take my filter off when shooting into the sun. Otherwise. Yech.</p>

<p>I use one on my lenses except for a couple that have a pretty deeply recessed front element (basically my 55mm micro and my 50mm f1.8.</p>

<p>Filters as "protection" can act in the opposite fashion. When a lens with filter is dropped, the filter can break and bombard the front lens surface with glass shards to destroy the lens completely. I've seen this happen so it's not theory (cost me a brand new 35/1.4). From other people's stories I know I'm not alone here.</p>

<p>Use the designated lens hood at all times. Experiment to see whether a longer/narrower than factory specified hood can work without vignetting.</p>

<p>When shooting near storm surges or similar, a filter could be considered, not as a protection measure but rather to make it easier to clean the lens.</p>

<p>I personally don't. If you take moderate care of your lenses, you don't really need filters. The only time you may need it is if you go to some rough places with hard to predict environment. eg. beaches, deserts, etc..</p>

<p>OK, we're taking filter stories again. Last week I was out in the deep snow with a friend, chasing trains. He had two cameras. One was in his hand, the other was in the big cargo pocket of his parka. He stumbled on his snowshoe and the camera in pocket flipped out and landed "face" down in the snow. I heard a cracking sound. The lens had landed on the top of a metal post that was barely sticking up out of the snow. He was actually surprised (LOL!) that his "protection" filter didn't protect the lens. The lens was severly damaged and not only that an expensive B+W filter was trash. Using the filter made him feel the lens was protected. If he had the lens cap on instead, it would certainly have resisted the impact. BTW, looking at his photos vs. mine from same spots, most of his had flare. Only one of mine did. He said he will now get rid of the filters and start using lens caps and hoods like I do.</p>

<p>Kent in SD</p>

<blockquote>

<p>"Don't filters increase the risk of flaring and ghosting and is that significant for the protection they afford? They may degrade the image if lesser glass is employed, right?"</p>

</blockquote>

<p>Yes, particularly if lesser coatings are used. It's significant if you're in a situation when using a filter is contraindicated.</p>

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<p>"Modern lenses' coatings MUST absorb UV and "skylight," right?"</p>

</blockquote>

<p>Mostly no, but a few do. Lens coatings are generally formulated to be color-neutral. Blocking UV that's near-visible affects violet colors (think clouds in sunsets, horizons in sunrises, etc.), and can make certain things look dull (notice how the phosphate brighteners in laundry detergent 'light up' a white shirt under 'black lights' in a disco or a gentlemen's club). Your shirts are whiter in daylight because they reflect near-visible UV. IIRC, the band pass filter over the sensor blocks non-visible UV (and IR), but this varies by camera make and model.<br>

Skylight filters knock out the bluish cast in open shade during broad daylight by 'warming' it ever-so-slightly. Look at a Skylight 1A against something trally white, and you'll see they're slightly pink. You want that color on you lens 100% of the time?</p>

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<p>"So if one will use a filter, why not a clear glass filter?"</p>

</blockquote>

<p>Sounds good to me, but I usually use a moderate UV filter to cut haze from high humidity at sea level in seascape shots. A clear glass filter doesn't cut haze as well.</p>

<blockquote>

<p>And, finally, wouldn't the public be better served if lenses, both high and low end, were sold with a filter, that could be used if desired?</p>

</blockquote>

<p>What single filter would possibly be used by all photographers for all things? This is the reason DSLRs don't ship with good mem cards and imaging software. Different folks have different preferences. The other side of that coin would be sticking customers with filters they don't want or need for their photography - they know they're paying something for it, and will complain. It's best to let the photographer make their filter choices, since the camera company doesn't know the photographer's intent. It's like imaging software...everyone has their own preferences on how to achieve what they envision for their photographs.</p>