At 00:42 21/02/01 , Peter K replied to Geoff Doane:
>Although I have UV filters for most of my lenses, I rarely use them,
>preferring a lens hood to protect the front element. I can't honestly say
>that sharpness is impaired, but I have seen them cause flare or ghost
>images. If I expect salt spray or dusty conditions, I would use a UV
>filter, but they do provide another air/glass surface to cause flare under
>difficult lighting conditions. The UV filters have also been used when
>I've inadvertently lost a lens cap.
>_____________________________________________________
>
>Geoff,
>
>You bring up a good point. Adding another glass/air surface can cause a
>problem. A hood is the best insurance one has against this added surface to
>cause a problem at all. The reason you use a UV is to pull out the blue in
>high altitudes or near the ocean. Aside that they gain you nothing. UV
>filters are defined by L #s. The higher the # the better the filter to
>eliminate UV. Hoya is an L39 but the new Super HMC Pro UV are L41. Nikons
>and others are L37 (surprise!).
>To see if your UV is worth anything, place it on a flurescent light (light
>box if you have one). If the UV turns a yellow tint with the light on its a
>decent filter. If it does nothing, its junk!
>
>Peter K
During the recent Lunar Eclipse I noticed 'flare' in the viewfinder while
using the 70-200 f2.8 and I wondered what was causing this. I now realise
that it must have been the UV filter on the lens. Am I correct in this
assumption?
Bob Turner
*
****
*******
***********************************************************
* For list instructions, including unsubscribe, see:
* http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************
