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Photography Question 
Howard 
 

Is It OK to Keep UV Filter on Lens All the Time


Is it a good practice to keep UV filter on my 28-200 wide angle zoom lens at all times to protect my lense?


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6/4/2002 3:26:04 PM

 
Jeff S. Kennedy   I'll put it this way- it's a common practice. It will help to protect your lens. When sharpness is a concern I will shoot without a UV filter in place.


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6/4/2002 4:07:15 PM

 
John A. Lind
BetterPhoto Member Since: 9/27/2001
  Jeff,
How diplomatic! :-)

This question has sparked Holy Wars on other forums with passionate opinions for and against UV filters.

Actually, your zoom has enough glass in it that likely very, very little UV is reaching the film. Glass naturally attenuates UV.

I use one quite often outdoors and indoors with flash when using prime lenses with much fewer elements (about a third of what your zoom has). It does cut the UV content outdoors and most of my flash gear has a relatively high UV content.

I take the UV filter off for available light night photography, and under situations during daytime with very bright light sources, especially pinpoint sources, in the image. Reason? To avoid reflections of these bright light sources from the two air-glass interfaces added by the filter and the ghosting of them it can create in a photograph.

Jeff is quite correct that adding anything to a lens affects its optical qualities. When using a filter, another element/group is added to the lens optical system. It will affect optical performance in both resolving power and contrast. The better, coated filters such as Heliopan and B+W do not affect it as much as the dirt cheap, uncoated no-name generic ones (which can be a source of flare and spurious reflections).

Whether or not you can detect this in your photographs depends on
(a) baseline lens performance and film resolution which form a "system" resolving power, plus
(b) how large you enlarge the resulting images (which will reveal resolution limits more readily).

-- John


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6/5/2002 12:50:21 AM

 
Jeff S. Kennedy   I just love it when John follows up on an answer of mine. I see most questions as yes or no and answer them as such (perhaps a weakness on my part). John, on the other hand, usually writes a thesis on the same subject and you'd better have your photography lexicon with you when you read it. :-)))


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6/5/2002 12:33:00 PM

 
John A. Lind
BetterPhoto Member Since: 9/27/2001
  Got carried away beyond the risk of stray reflections from pinpoint light sources.

It's a weakness of mine . . .

:-))))))

-- John


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6/5/2002 1:42:58 PM

 
Jeff S. Kennedy   :-)))


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6/5/2002 3:49:49 PM

 
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