John wrote:
>
>
> Wayne wrote, of cross-polarisers and flash:
> > More bad news: Reflections from an electrically conductive
> > surface are not polarised, so using the polarisers doesn't help.
>
> I think I disagree. Surely the thing about metallic surfaces is that
> they have no polarising effect, so if the light is polarised in a
> particular plane when it hits the surface, it stays polarised
> afterwards.
>
Correct.
> The converse is if you have something like water, which does polarise.
> You only need one polarising filter to stop reflections from water (if
> you're at the right angle) because the polarising effect of the water
> itself is doing the same job as the part of the cross-polariser on the
> flash.
>
> Does that make sense?
>
Yes.
So what is the benefit of using crossed polarisers on flash and lens when
photographing a metallic surface ?
Wayne Harridge
Ivanhoe, Victoria, Australia
http://www.geocities.com/wayneharridge/
< 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 >
|