[Leica] RE: Polarizing Filter

[paulm.franz@ps.ge.com]

I am not an expert on this issue, but I believe the following information
from the Schneider Optic FAQ page, is valid.  

http://www.schneideroptics.com/faq/faqbw.htm

What is the difference between a Linear and a Circular Polarizer?

                       "A Circular Polarizer is a Linear Polarizer with a
1/4 wave plate
                        added to the polarizer. Circular Polarizers are
necessary when
                        using an SLR that has a beam-splitter which is used
for internal
                        light meter reading. The beam-splitter polarizes
light and
                        depending upon the position of the polarizer, you
may cause
                        double polarization and therefore get inaccurate
meter
                        readings. Circular Polarizers are also necessary for
auto focus
                        cameras. "

I believe M series meters do not require a circular Polarizer, while the R
series meters require the circular polarizers. 

Regards  

Paul Franz

> At 04:51 PM 27/01/99 -0500, you wrote:
> >Armed with the good information that I received from this list about
> >filters, I went to NYC today to buy circular B + W multi-coated polarized
> >filters. The sales clerk at B&H, who was quite helpful, told me that I
> >didn't need a circular filter for my R4. I had just read in the Bove
> manual
> >that was the one to use for the R4. I got confused and ended up buying
> >neither. The sales clerk said that the circular filters are only needed
> for
> >auto focus cameras.
>