I don't have Pentax PL filter. However, I have B+W & HOYA cir-pl (regular uncoated) and did some outdoor test shots on tripod. Both slides have identical sharpness and colour rendition (under 8X loupe as well as scanned by 2820dpi film scanner). In fact, both slides are as sharp as the slide without filter. Personally, I don't like the thick B+W filter mounts and feel they are way overpriced. I have read some complaints on the quality of HOYA filters but I have been using HOYA for 12 years and like them very much. However, Pentax SMC are much more flare resistance than HOYA HMC. SMC filters have very thin and rigid filter mounts too (much better than B+W).
regards, Alan Chan > Hi! Actually it is my very first question set here! > I need to know your experience, knowledge or opinion about filters from > Pentax, Heliopan and B+W. I think about polarizing, warming and yellow > multicoated filters. I got impression that Heliopan and B+W are the best, > but that "best" is actually without comparison to Pentax filters. I wonder > about scratch resistance, easyness of cleaning, quality of mount, neutrality > (in case of polarizer), flare or other image degradation, variety and > ability to make mixed brand sets, say for different gradation of warming or > darkening sky. > Why brass is better than aluminum? > > I have very limited experience with filters. Once (and long ago) I had a > Russian linear polarizer, buy it had marked greenish tint, so I could not > use it for color slides.
