What exactly does a polarizing or UV filter do for your photo clarity?

Discussion in 'Nature' started by wade_thompson|1, Apr 10, 2016.

  1. I have a new lens and just wanted to get your take on the importance (or unimportance) of adding a filter.
    Pros and cons?
    Thanks
     
  2. SCL

    SCL

    UV filters significantly cut UV radiation, essentially reducing atmospheric haze. Polarizing filters are used to reduce glare reflected off objects, and also to intensify colors when multiple polarizations of light are at certain angles relative to the plane of your sensor - such as the sky in certain situations. The most common use of filters, however, is to protect the front elements of a lens from things like sand, dust, dirt, rain and impact. The cons may or may not be an issue for you depending on the conditions in which you shoot, your camera body's metering, whether you are using wide angle lens or not, and include such things as additional weight, cost, efficacy (or lack thereof with wide angle lenses). Best you get a good book and read up on the nuances, as well as your camera's owner's manual to determine if your body requires a normal polarizer or circular polarizer for metering (and occasionally focusing) .
     
  3. A polarizing filter is also effective at reducing haze in distant scenes, especially in dry climates. Haze due to fine dust and small amounts of water vapor is polarized for the same reason the sky is polarized. For this and other reasons, a polarizer is an important tool for landscapes.
    It is also the only filter which will preferentially darken clear, blue sky for color film, as mentioned briefly in the previous post. It's a nice thing for the eastern part of the country, but in arid regions or high altitude the effect is often too much, and can render the sky deep purple. The maximum amount of polarization is in a band 90 degrees from the sun. It can appear as an odd streak of blue with a wide angle lens.
    IMO, a polatizer is best used to reduce reflections of the sky from non-metallic objects, like foliage, dirt and rocks, making the colors more saturated, or excessive reflections from water. Regarding water, a polarizer can render water a muddy brown if used in excess.
     
  4. Here is an example page of somebody using UV for landscape photography, with white light shots to compare to.
    http://www.pbase.com/kds315/landscape&page=7
    IMHO UV filters are a "toss a coin" decision. They might help sometimes. They are overpriced. And if you buy cheap uncoated (ab)used ones they might even reduce image quality.
    Polarizers seem nice to have, if you have the light to waste with them and are looking through your lens.
     
  5. I'd not waste your money on a UV/clear filter unless you have a weathersealed lens and require it to complete the seal.
    A polarizer can indeed be useful, but I have to admit I rarely use mine. It can be useful to reduce reflections in water and other surfaces and does darken blue skies. However, a little goes a long way: after a while tourquoise water and overly dark skies can become too much. Likewise it is a toss up whether reducing reflections from leaves and wet rocks is necessarily an improvement over a naked lens' rendering of the same scene. So, use with care, but you may want to try one.
     
  6. Most every lens I buy gets a haze/UV filter before I leave the store, as protection against the odd impact or scrape. I buy filters of sufficient quality that their negative impact on the images is minimized. The only lens which does not have a filter is my 55mm macro, since the objective is deeply recessed in the lens body. Filters have saved me substantial costs for repair/replacement a couple of times.
    I found out the hard way that a polarizer is not a good idea on a UWA lens. It will create a band of sky much darker than other portions of the frame, making for a rather strange presentation. I find it works great on any lens over 30mm. I also use a polarizing-type variable neutral density filter to allow longer exposures in bright light. I find it easier to use when focusing, in lieu of fixed or stacked ND filters. I focus with the obscuration turned to the lowest setting, and then simply rotate to the desired setting before tripping the shutter.
     
  7. We discuss the merit of this lens over that, what glass is sharper than which; we Google, read test reports; then maybe someone would chime in with something like Oh, well, my $10K Leica beats them all,... etc. After all of this, why then should we filter out its prowess with a sub $50-or-less UV filter?
    When there is no climatic condition that demands it, I would recommend taking it off before you click the shutter to make that monumental spectacular award-winning shot. :)
    Just found an article that provides a few points of view (link).
    Enjoy your new lens Wade.
     
  8. A UV filter does cut down on haze but it is virtually clear, which is why it is a popular choice as a protection filter. In practice, you will usually see very little difference in the appearance of the image when using it, at least in my experience.

    A polarizing filter can provide very dramatic results. It's a very easy way to get postcard-style deep blue skies with puffy white clouds. It can also eliminate reflections on wet objects and glass, as noted. it is very popular in landscape photography and I use one frequently on landscapes. Yes, you can overdue it and yes it can have problems with extreme wide-angle lenses. But I consider it an essential filter to carry for landscape work.

    As for protection filters, every one of my lenses gets a UV or skylight the day it's purchased and they only come off to put another filter on. But I come from a newspaper background where a recessed front element or a lens hood isn't enough to protect from all the things that have come flying at my lenses over the years. And most of my work was reproduced through a a halftone screen on newsprint (or these days at 72 ppi on a computer screen), so losing a small fraction of sharpness has never been an issue for me. Your situation may be different.
     
  9. I have found they act as good lens protectors, but never wasted the money on one personally. I enjoy using a circular polarizer instead as a go-to all purpose filter, even with the light stoppage difference it usually works out to cut down on glare, the way one would expect the UV filter to.
     

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