I am a hobbiest, so If I sound stupid, don't rail me.
I have 3 L lenses (70-200 2.8, 100-400, 17-40) My understanding is that the glass is coated with a UV coating. If this is true than why put a UV filter on them?
If we pay all this money for L glass, is the UV filter as good of quality glass?
I've read the 100-400 doesn't work well with a UV filter, is that true?
You are supposed to put a UV filter on your lenses (particularly the ones with large diameter filter threads) so that your local camera dealer can turn an extra profit.
UV-Filter are not necessary. They should block the UV-Light but today the most lenses have special glas against uv-light plus your cmos-chip of the cam has a own filter.
If you need a filter, you should buy a polarizer. It helps against reflections.
omarlyn wrote:
ALSO...some of the newer lenses with the 'weather-resistant' construction & gaskets actually require a filter to complete the sealing.
What does that mean? If a lens is built and labeled as weather resistant, it comes out of the box weather resistant. Otherwise there would be a disclaimer or warning to "purchase and install an additional filter".
There are those who use UV filters for protection on all of their lenses ("I would rather damage a filter, rather than the front element of the lens"), and there are those who never use them (because they believe the additional glass will degrade the image) except in very adverse conditions (i.e. a sandstorm), and feel that the lens hood is suffiecient protection. And, as already mentioned, some of the newer L lenses require a filter to complete the weather sealing. I use a filter on all of my lenses. If you decide to use UV filters, buy only the very best - B+W or Hoya HD.
jkristaken: A knowledgeable salesman at Calumet told me that a UV filter in front of the lens reduces the light entering the lens by 0.10 to 0.15 percent -- virtually insignificant. Wikipedia has this comment on UV fliters:
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UV filter
From Wikipedia, the free encyclopedia
UV filters are individual compounds or mixtures to prevent ultraviolet (UV) light from coming through. UV filters used in sunscreens to protect skin or in photography to reduce haziness or fogginess created by ultraviolet light.
A UV filter in photography is transparent to visible light, and so can be left on the lens for nearly all shots. As UV filters are usually inexpensive (about US$20, depending on size), many people use them as protection for their lenses, although this is subject to some controversy.[citation needed] For this purpose they are preferred over other kinds of filters which are more intrusive, such as neutral density filters.
The UV filter absorbs ultraviolet rays without changing the exposure. With most images, most people will not see a difference when a UV filter is used.
[edit] See also
Photographic filter
Retrieved from "http://en.wikipedia.org/wiki/UV_filter"
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I hope this info clarifies this issue.
I've heard stories of airsoft photographers who stack 3 to 5 UV filters on their lenses. One particular story I heard had a photographer take a direct shot from an airsoft pellet right into the front of a 70-200 f2.8 IS. The pellet broke thru the first 3 UV filters stopping at the 4th!!
Cost to replace 4 filters = $80
Cost to replace 70-200 f2.8 IS = MUCH MUCH MORE than $80.
on film cameras they served a purpose other than physical protection (UV can affect film). On Digital cameras they serve only to protect the front element of the lens. Useful for some, pointless for others, opinions vary. As for image quality thay can have some effects but it can be impossible to tell the difference between a UV filtered image and a non-filtered image, especially when high-quality (expensive) multi-coated filters are used (B+W MRC, Hoya S-HMC and up).
I'm in the "I wish I could do without but am too scared that I'll ding my front ring/element" camp
kaybeejay wrote:
I've heard stories of airsoft photographers who stack 3 to 5 UV filters on their lenses. One particular story I heard had a photographer take a direct shot from an airsoft pellet right into the front of a 70-200 f2.8 IS. The pellet broke thru the first 3 UV filters stopping at the 4th!!
Cost to replace 4 filters = $80
Cost to replace 70-200 f2.8 IS = MUCH MUCH MORE than $80.
True, but then the quality of images he is getting from having 5 very cheap UV filters on his expensive lens is the same as using a $200 lens in the first place.
UV filters are mainly used to protect the lens from damage. If you were to drop your lens, the chances of the front element being damaged with a filter on it is much less likely than if you had no filter. I use a combination of a hood and a filter on my lenses for maximum protection.
Don't buy cheap UV filters, the cause flare and ghosting and reduce your image quality. Buy a B+W MRC (multicoated), they are the best.
I am sorry if this has been disused in detail before, I should of done a search.
Thanks for the clarity.
A polarizer will reduce Reflections? But not IQ?
I am going to Florida next week and hope to get plenty of shots of the abundant wild life and scenery. I was worried about the harsh sun light.
UV filters are purely protection. Others like polarizers serve a purpose by changing hte image in some way... in bright sun a polarizer would be good to have but using it is not a given.
It cuts out some reflected light, having a dramatic impact in some cases (sky, water, colors) but that means, of course, it'll cut overall light so exposure will have to increase to compensate -- not always a good thing if you're using long glass or are working in lower light conditions (sunrise etc.).
chez wrote:
True, but then the quality of images he is getting from having 5 very cheap UV filters on his expensive lens is the same as using a $200 lens in the first place.
Just what I was thinking. But then cost of 4 B+W filters = $300 = still less than 70-200
pipspeak wrote:
UV filters are purely protection. Others like polarizers serve a purpose by changing hte image in some way... in bright sun a polarizer would be good to have but using it is not a given.
It cuts out some reflected light, having a dramatic impact in some cases (sky, water, colors) but that means, of course, it'll cut overall light so exposure will have to increase to compensate -- not always a good thing if you're using long glass or are working in lower light conditions (sunrise etc.).
It sounds like a polarizer Would be a good investment for me. A lot of my shots are out in the bright sun.
jkristaken: A polarizer filter causes about a 2-stop drop in exposure. This filter remains indispensable for now, for the reasons given. I agree with others on buying the best filter you can afford.
Wikipedia has an informative discussion [edited below] of photographic filters at:
A polarizing filter, used both in color and black and white photography, can be used to darken overly light skies. Because the clouds are relatively unchanged, the contrast between the clouds and the sky is increased. Atmospheric haze and reflected sunlight are also reduced, and in color photographs overall color saturation is increased. A polarizer is ineffective if the camera's filmbay is not loaded correctly. Polarizers are often used to deal with situations involving reflections, such as those involving water or glass, including pictures taken through glass windows (this uses the phenomenon of Brewster's angle).
The benefits of polarizing filters are largely unaffected by the move to digital photography: though software post-processing can simulate many other types of filter, most of the optical effects of controlling polarization at the time of capture (particularly where reflections are involved) simply cannot be replicated in software.
Polarizers are often used to improve the appearance of vegetation.
There are two types of polarizing filters generally available, linear polarizers and circular polarizers (or CPL filters). With the exception of how they interact with some autofocus and metering mechanisms, they have exactly the same effect. Both transmit one of two states of linearly polarized light. The difference is that a circular polarizer alters the light leaving the filter and entering the camera by using a quarter-wave plate to circularly polarize that light. This has the same effect photographically as a linear polarizer, reducing glare in the scene.
The metering and auto-focus sensors in certain cameras, including virtually all auto-focus SLRs, will not work properly with linear polarizers because the beam-splitters used to split off the light for focusing and metering are polarization-dependent.
Circular polarizers work with all types of cameras, because mirrors and beam-splitters reflect both circular polarizations equally.
Retrieved from "http://en.wikipedia.org/wiki/Photographic_filter#Polarizer"
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I hope this info helps.
