UV Filter & Polarizer Filter Pictures

[neuroanatomist]

If you get good quality, multi-coated filters (e.g. B+W MRC or the high-end Hoya filters) then you can stack them without loss of image quality, as long as you're not vignetting. Stacking even slim filters on a UWA lens like a 16-35mm on FF or a 10-22mm on a crop body is likely to vignette at the wide end. Keep in mind that a slim CPL is the same height as a standard filter.


Personally, I keep B+W MRC UV filters on my lenses at all times. The F-PRO mount is pretty thin, and on my 10-22mm I use the XS-PRO mount, a slim filter that retains front threads. If I need a CPL or ND filter, have time to set up, and I'm in a dry, non-dusty environment, I remove the UV and put on the other filter. If I'm short on time, or at the beach, etc., I stack other filter onto the UV.

[Keith B]

Pardon my filter ignorance, but a UV filter really doesn't do much on modern lenses and digital cameras other than protect the lens and arguably reduce image quality. Correct?


Whatever IQ improvements (if any) a UV could provide would also be achieved with a polarizer. Correct?


Then why would it be necessary to use both? It seems this would just reduce IQ for no good reason.

[Daniel Browning]

I agree with the rest -- better to remove the UV when using the pola.

Pardon my filter ignorance, but a UV filter really doesn't do much on modern lenses and digital cameras other than protect the lens and arguably reduce image quality. Correct?

Yes. Most modern lenses already block UV, and for the ones that don't, the sensor cover glass blocks it. Any UV that makes it pass that will fail to register as the sensors themselves also have low response to UV (unlike film).

[neuroanatomist]

Pardon my filter ignorance, but a UV filter really doesn't do much on modern lenses and digital cameras other than protect the lens and arguably reduce image quality. Correct?

<div>Yes. Most modern lenses already block UV, and for the ones that don't, the sensor cover glass blocks it. Any UV that makes it pass that will fail to register as the sensors themselves also have low response to UV (unlike film).</div>
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<div>Daniel is, of course, completely correct. So, why then would anyone buy a UV filter, for the sole purpose of protecting the lens (and keep in mind that a filter of some sort is required to complete the weather-sealing of all 'weather-sealed' non-supertelephoto L lenses). Partly it might be because most of the discussions on this issue center around UV filters vs. no filters, and not many people mention clear protection filters. But, there are some other reasons.</div>
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1. At least in the B+W line, multicoated UV filters are slightly cheaper than equivalentlymulticoatedclear 'protection' filters. So, for example, on Amazon a B+W 72mm MRC 010 UV is $63, while a 72mm MRC 007 Clear is $74. On the other hand, for the Hoya DMC Pro1 filter line, clear filters are cheaper. But then, I use B+W, not Hoya.
2. UV filters are more widely available - for example, on Amazon the B+W 67mmMRC 007 Clear is currently listed as unavailable.
3. Your Canon EOS lenses also work on Canon EOS film bodies. Although from an optical point of view, there's no difference between an UV filter and a clear filter for a dSLR, there is for a film SLR. Who knows - maybe you might decide to grab a roll of 35mm Ektachromeand start shooting, or loan your lens to someone who does...

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Whatever IQ improvements (if any) a UV could provide would also be achieved with a polarizer. Correct?

On a dSLR, the UV filter is entirely about protection, not IQ improvement. While a UV filter (or a clear filter, for that matter) does have an effect on light transmission, with high-quality multicoated filters the light attenuation is of neutral density (no color shift) and is less than 3%, effectively unnoticeable. A polarizer reduces light transmission by ~2 stops - that's not something I want to leave on my lens all the time.

[Luis Diaz Gimenez]

I am a little hesitant when replacing the UV filters that I always have on all my lenses with C-Pol filters, specially in harsh conditions as I always prefer to clean a filter instead of a front element. Having said that, I end up not stacking as Iratheravoid vignetting or more flare or ghosting than otherwise unavoidable.

[Keith B]

On a dSLR, the UV filter is entirely about protection, not IQ improvement. While a UV filter (or a clear filter, for that matter) does have an effect on light transmission, with high-quality multicoated filters the light attenuation is of neutral density (no color shift) and is less than 3%, effectively unnoticeable. A polarizer reduces light transmission by ~2 stops - that's not something I want to leave on my lens all the time.

I understand that folks love to protect there lenses with UV, but while there is a polarizer on there, isn't it providing the protection. Is this a question of laziness or the fear of the 30 seconds the lens will be unprotected? No one suggested keeping the polarizer on all the time.

[neuroanatomist]

Sure, the polarizer will protect just as well (if not better - there are two layers of glass in a CPL). For those who do stack, it's either laziness (not that I'm accusing anyone here of that!), or simple lack of time (needing to get the CPL or ND on quickly to avoid missing a shot in the time it would take to remove the UV filter). In some cases, it might be "the fear of the 30 seconds the lens will be unprotected" - if I was shooting on a beach with crashing breakers and lots of salt spray, and wanted a CPL to cut the glare or an ND to blur the water with a long exposure, I would just screw on the second filter, rather than removing he UV filter and needing to clean off the front element later. Then, if I needed to keepshooting with that lens once I left the beach, before I got a chance to properly clean the UV filter, I could just remove it and keep shooting.

[Ralph]

if I was shooting on a beach with crashing breakers and lots of salt spray, and wanted a CPL to cut the glare or an ND to blur the water with a long exposure, I would just screw on the second filter, rather than removing he UV filter and needing to clean off the front element later. Then, if I needed to keepshooting with that lens once I left the beach, before I got a chance to properly clean the UV filter, I could just remove it and keep shooting.
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Exactly! Here's a sample:





Canon 50D + Canon 10-22 + Kenko slim UV + Hoya Pro1D slim CIR POL


You don't want me to remove my UV and replace it with CPL on THAT location would you? [:P] And oh, I'm well aware of the vignette (atleast after I learned to stop at 12mm instead of 10)