If I am not mistaken circular polarizers are required only in the case of autofocus systems, manual focus lenses can be used with the original style polarizers which you may own already. I have used such with a variety of manual focus cameras and lenses including Leica R and Minolta bodies... in auto exposure mode as well as manual and they worked fine. There may be some other asthetic consideration where the circular ones are more pleasing photographically, I don't know...opinions? ----- Original Message ----- From: Dr. Elliot Puritz To: leicareflex@xxxxxxxxxxxxx Sent: Sunday, January 16, 2005 6:59 PM Subject: [LRFlex] Polarizer Might I ask a quick question regarding polarizers and two of the R lenses? With reference to both the 21-35 Asph, and the 28-70 zoom lenses ( not the uncommon Asph version ), is there any magic to using the polarizers? Does one simply obtain a circular polarizer of the correct size, and screw it in? Sorry for asking what must appear to be a very simple question. Elliot