Hi, every f-stop has a hyperfocal distance. The reason why one of them, generally f/8, is marked differently from say f/11 or f/16, both of which will of course give you greater depth-of-field and are therefore better from the hyperfocal point-of-view, is that f/8 is the optimal aperture from the optical quality pov. So it was quick and easy to get the optimal combination of aperture and depth-of-field for hyperfocal distance. It is also why the phrase 'f/8 and be there' specifies f/8 rather than f/64 or whatever. If it was just about getting as much in focus as possible they'd all do it with the smallest aperture.
--- Bob mailto:[EMAIL PROTECTED] Monday, March 04, 2002, 8:14:20 AM, you wrote: >>I've always thought of this as a classic example of pointless >>automation. On the older series of prime lenses the optimal aperture >>was marked in a different colour from the others. In conjunction with >>the depth-of-field scale on the lens this did everything that the MTF >>programme does, and all it requires is paint and a fine brush. A nice >>simple >>solution. > I think you misunderstood the purpose those "red" indicators (and I don't > mean the infra-red index). On some old Pentax prime lenses, just match the > red colour aperture and focus setting, and you can just shoot without > further focus. It's more or less like a focus free P&S camera. > regards, > Alan Chan > _________________________________________________________________ > Chat with friends online, try MSN Messenger: http://messenger.msn.com > - > 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 . - 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 .
