Same here.[:P]Originally Posted by neuroanatomist
Same here.[:P]
I did have some time to test this today; I'll post the results in a fresh thread.
Hi, am a new member and have this question.
Do UV filters work on Digital SLR cameras ? Cause I saw the literature on the Canon UV filter saying that the UV protection does not work for Digital cameras?( rather makes no difference unless it is a camera with film. Is this true?
I have a EOS500D with 55-250 lens, for which I was looking toi use the UV filter as a basic protection cum UV filter.
The CMOS/CCD sensors in digital cameras are essentially insensitive to UV wavelengths, so a UV filter is not needed to eliminate the 'outdoor haze' as was the case for film. Thus, the sole purpose of a UV filter on a dSLR lens is for protection of the lens. There are clear protection filters as well, but for various reasons they are more expensive (at least from some manufacturers). Optically there's no difference between clear and UV filters for a dSLR.
Whether or not to use a filter for protection is a hotly debated topic, and it comes down to personal choice (and sometimes lens choice, as well). Adding any additional optical element(such as a filter)to the systemcan affect the image quality. In the case of a UV/protection filter, you don't want it to affect the image quality at all. Low quality filters (the $5-20 ones from Tiffen, etc.) are likely to degrade image quality - those are generally uncoated or single-coated filters, meaning they'll cause reflections, etc. Note that the Canon UV filters also fall into that 'low quality' bucket (apparently, they're actually made by Tiffen, and they're the low end of Tiffen's line-up, which isn't great even at the high end). High quality, multi-coated filters (B+W MRC, the Hoya Super HMC line) will have almost no effect on IQ - but those are expensive filters.
Personally, I use B+W MRC UV filters on all my lenses - the MRC coating makes them easier to clean than the front element (supposedly, the Hoyas are harder to clean), and for many weather-sealed L-series lenses, a filter is actually required to complete the weather-sealing. But they're not cheap, especially in the larger sizes required for the higher-end lenses. What I've spent on UV filters would pay for 70-200mm f/4L lens.
In your case, the EF-S 55-250mm lens uses a 58mm diameter filter - a good quality filter in that size is ~$40.
One other point to consider - in many cases a lens hood provides better protection than a filter, and also offers optical benefits by blocking stray light. I'd definitely recommend getting the ET-60 hood for yourEF-S 55-250mm lens, and if budget forces you to choose hood vs. UV filter, choose the hood.
Thanks a lot for the in depth reasoning for the filters. It sure was descriptive and detailed too.
Just one thing though... as in the case of our eyes (vision) , using colored sun glasses, changes the perspective of what we see and enhances our vision in terms of clarity.Likewise if the filter was lightly shaded ( not clear or UV), will this not enhance the clarity of the image in digital SLR's too?
Just applying the same logic. Or is it that the seemingly enhancement perceived by the eyes to the image coming through colored sun glasses , is actually perceived by the sensors in the eye as 'clarity in vision' and is not so in reality!!??
Likewise the sensors in a DSLR , should they not be affected/enhanced by the image as it filters through the 'filter' and hence must be ehnanced in clarity? If yes, then the IQ with the use of filter (lightly shaded, not UV) ought to give better results even with DSLR's.
It depends on the type of filter you're talking about, and what you mean by 'enhanced'. A colored filter (or sunglasses, for that matter) is going to add a color cast to the image, although you would not notice if you're using automatic white balance (which balances to a neutral gray and thus tends to remove/reduce the effect of a colored filter). Personally, I'm not a fan of 'rose-colored glasses' (or any other color, for that matter), and my sunglasses are neutral density - they reduce the amount of light evenly at all wavelengths, i.e. they are 'gray'.
I suspect you may be thinking of polarized sunglasses, vs. 'colored'. Polarization 'enhances' and 'adds clarity' because it removes out-of-plane reflections and thus increases contrast. A circular polarizing filter for your lens will have the same effect, and is a very useful filter (but not one to be left on all the time, as it results in a loss of 1.5-2 stop of light).
In a nutshell, when discussing filters for dSLR lenses, the only ones to consider are:
- UV/clear (for protection)
- Circular polarizing (to reduce reflections, useful for foliage, bluer skies, etc.)
- Neutral density (reduce the amount of light, useful for slow shutter speeds for waterfalls, etc., and for shooting outdoor portraits with wide apertures)
- Graduated neutral density (for unevenly lit landscape shots, where the sky is much brighter than the ground)
Those are really the only filters where the effect cannot be easily reproduced in post-processing (debatable for graduated ND filters - can be done in post, but it's a lot of work; HDR is another option in those situations).
Hope that helps...
--John
Thanks John for your indepth reply. It sure did help clarify many doubts I had regarding filters.
Atul
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