Albert, I recently faced a similar purchase when I shopped for a 67mm UV multicoated filter for my Rikenon 28-100/4 zoom. The thinnest would be a B+W slim, but it would also be the most expensive (about $67) and wouldn't let me thread on a hood. The next-thinnest would be Heliopan ($47), followed by Pentax ($54) and Contax ($32). I had been told by Contax tech support that another size (52mm?) was as thin as the Heliopan slim. the price was right, so I hoped the 67mm Contax would be similarly slim.
Well, it isn't. It's about 5mm. For a hood I use a 67-to-77mm stepup ring. But Geoff Moes peered through it and pointed out that it vignettes. So if you plan to use a screw-on hood, be sure to get as slim a filter as you can. Yes, Hoya multicoated filters have a deserved reputation for being hard to clean. But at http://www.2filter.com you can buy a cleaning fluid designed to clean Hoya multicoated filters. Albert Fekson wrote: I am about ready to order the FA 24mm and I would like to know if it requires the use of thin-ring filters to prevent viginetting. It seems that this lens has a very large diameter and does not need thin filters. I am thinking about Hoya HMC UV(0), although some people complained that Hoya's multicoating is not only difficult to maintain, but also leaves green cast on images. I can go with only hood for protection, but a filter seems like a good idea, an "insurance policy" if you will. Pentax filters of that size are a bit out of my price range so I am a bit unsure about my option. Paul Franklin Stregevsky - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
