At 2000 August 4 - Friday 2:57, Lex Jenkins <olympus@xxxxxxxxxxxxxxx>
spoke about *Re: [OM] What lens to carry (again)...* saying
> Shouldn't be any difference in light transmission regardless of how a
> polarizer is rotated. What can vary is the light meter reading when a
> linear polarizer is used on a camera that requires a circular polarizer
> (like the Can-not-an-OM-on FTbn).
Of course it should vary! Eliminating the sun reflection off a
windshield could mean a couple of stops variation between one
rotation position and 90 degrees away. The 1.3 stop suggestion is
just an average for handheld, non-polarised lite meters.
Theoretically, it should be 1 stop since you've eliminated 1/2 the
energy by choosing the light waves energy component in just one
direction. The other .3 is wastage in the filter.
Think of it. If *all* the light were polarised in one direction,
You'd get full transmission (less the wastage) at one rotational
point and zero transmission 90 degrees away.
Tom
...
> >From: Robinsnes@xxxxxxx
> >Date: Thu, 3 Aug 2000 22:02:08 EDT
> >
> >In a message dated 8/3/00 9:35:35 PM Eastern Daylight Time,
> >Wayne.Harridge@xxxxxxxxxx writes:
> >
> > > Rotated out of the
> > > > position that cuts
> > > > glare, it's good for about 2-3 stops like an ND. YMMV
> > > > depending on what
> >I was under the impression that it was always a light loss of 1.3 stops to
> >adjust for the filter. Am I unaware of some changing variable?
> >
> >Roger Skully
> >robinsnestphotography.com
------------
Tom Trottier <TomATrottier@xxxxxxxx> ICQ: 57647974
Abacurial Information Technology Consulting
400 Slater St. Suite 415, Ottawa ON Canada K1R 7S7
__o +1 613 291-1168 fax:594-5412 (877)247-8796
_ \< Vote for your favourite Olympus camera at
(+)/'(+) http://www.freevote.com/booth/fav_camera
< 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 >
|