On Mon, 16 Feb 1998 15:49:15 +0000, JOHN B. CORNS wrote: >It is a popular misconception that polarizing filters change the film >exposure as you rotate them, something that even the filter makers allude >to on their instruction sheets when they show the exposure change as "1.5 >~ 3.0 f/stops", or "2.0 ~ 4.0 f/stops" or whatever (I never saw two of >these figures alike in the old days of the 1960s). This is only >partially true and is very misleading.
Hi Folks: Thanks to John B. for straightening me out. The last time I used the pola filter, I was under the impression that I had to use the camera's TTL meter, something I wasn't in favor of at the time. A few minutes ago, I picked up my pola filter and viewed the lamp on my desk across the room. As I rotated the filter, there was no change in the intensity of the diffused light coming through the shade. However, the reflections of light on the glass base changed considerably. This experiment confirmed what John said and, hopefully, made a lasting impression on my brain. Here's a question that John B. may be able to answer. I have heard that the axis of the sun relative to the axis of the lens affects the darkening of a blue sky, but I don't remember the result. I believe that the greatest darkening occurs with side lighting, i.e. the sun axis at a right angle to the lens axis. I am hoping that John can shed some (polarized) light on this topic or else tell us that I'm creating a problem that doesn't exist. Thanks again, John. Warren -> SPORRS: Serious Photographers of Railroad Related Subjects -> Web Site: http://www.anet-stl.com/acphotog/sporrs -> Message © SPORRS® 1998 - All Rights Reserved
