Thomas Haegin schrieb:
> Thanks for the link Richard, I'm kind of interested in this also
> because it's happening almost in my backyard. Hoya is selling some
> special NDx400 filter for this... ahould we get one?
It think 1/400 (ND 2,5 ?) is not strong enough. For photographic
purposes ND 3,5 1/3200 filter are recomended that´s ten times as strong. For
observation with your eyes ND 5,0 1/100.000 is suggested.
Be carefull, make sure, the filter also eliminates IR and UV rays.
This is an serious isue, if you value your eyesight and your camera
equipment.
B+W states, that there 1/1.000.000 ND 6,0 filter let pass an high amount
of IR rays. This is common with many ND filter (polarizers too).
Sun observation filter are normaly metal coated (and expensive), there
are also metal coated plastic (mylar?) foils which are much cheaper, but
filter IR, visible and UV rays. This foils are very thin and should be
OK for photographic purposes (exept for color rendition, but that´s true
for glass filters too), the same material is used for cheap sun
observations sun glasses. The drawback of the foil is, they might be
easily scrached and loose there protective properties.
Regards
Richard
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|