On Fri, Jun 23, 2006 at 02:11:59PM -0400, gfen wrote: > On Fri, 23 Jun 2006, Thibouille wrote: > > > It will because the camera allows you to manually select the focal > > length of the lens you put on it. > > Can someone fill me in? Its been more than a few years since I've paid > attention to anything that didn't require a tripod. :) > > I don't even know anything about the ist D. > > So, it needs to know the focal length? But, it'll stop down for me > automatically, I don't have to manually stop down to do everything? I > assume its not a full frame sensor, either, is it?
All the Pentax DSLRs ar so-called APS-C sensors - around 24mm x 16mm. This means the field of view you get with any lens is the same as the field of view you get on a 35mm camera with a lens 1.5x the focal length. The Shake Reduction circuitry on the K100D (and the forthcoming K10D) needs to know the focal length of the lens. With any of the auto-focus lenses (F or FA - basically anything introduced since 1987) the camera reads this information directly from the lens - you don't have to do anything. With older lenses you have to manually enter the focal length if you want to use shake reduction. All the Pentax DSLRs work best with lenses with an "A" setting on the aperture ring (if the lens even has an aperture ring). They lack the aperture sensing lever (this is what you'll often see being referred to perjoratively as the "crippled" K-mount), so with older lenses you pretty much have to work in metered manual mode. Even there, though, you can focus and compose at full aperture - the camera will stop down automatically during exposure. And while metering has to be done stopped down, rather than at full aperture, a single push of a button will stop the lens down, take a meter reading, select an appropriate shutter speed, and open the aperture again. This all happens faster than it just took you to read about it. But this is only necessary with really old lenses - (1975 - 1983). With the "A" lenses introduced in 1983 you get the full choice of manual, aperture priority, shutter priority or program exposures. And with the "F", "FA" or "DA" lenses you also get auto-focus. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
