OK ... I was the one who asked the original question, and thus far I don't see anything that makes a lot of sense (bearing in mind I'm technically challenged) other than that more aperture blades may slow down the speed of the aperture action during exposure. But, that would only make sense (if it does at all) for lenses that use automatic apertures. However, I've noticed that fewer blades are found on current Leica lenses, where aperture operation is set manually, yet, in the past, Leica used many blades, and now uses substantially less.
So that leads one to think about cost cutting as a reason, although that doesn't seem completely logical since some Leica glass is terribly expensive, and what difference would a few bucks make to the consumer who's already spending $1,000.00 - $2,500 or so for a lens? And, bringing it back to Pentax, auto aperture notwithstanding, many of our lenses are quite expensive as well, even when purchased at discount. IIRC, the A100/2.8 macro and the A*200/4.0 macro were both lenses that sold for about $1,000 or more at B&H, and since they were lenses manufactured in relatively limited numbers, the saving of a few dollars to Pentax would be minimal. I can see using cost as a factor on a typical 50mm lenses, where Pentax sells (sold) hundreds of thousands of lenses, but on a limited item where the consumer is going to be spending lots of money, where's the saving? Maybe I'm naive here - wouldn't be the first time. So, the original question still remains unanswered, at least in my mind: What's the advantage or disadvantage of a greater number of blades, apart from the shape it contributes to OOF highlights and the like? -- Shel Belinkoff mailto:[EMAIL PROTECTED] http://home.earthlink.net/~belinkoff/ - 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 .
