Hi, my meaning in that was probably not clear. I'm not suggesting that it doesn't use MTF data (it is the MTF programme, after all). What I meant was that when the shutter speed is too slow for the optimum aperture, it is unlikely to select the 2nd choice aperture (which must be wider than the optimum) on the basis of best available MTF performance, rather it's likely just to choose the smallest aperture consistent with a fast enough shutter speed, i.e. it switches to regular program mode. So I'd guess that the chip only contains one aperture value - the MTF optimum - rather than a sequence of aperture values in descending order of MTF optimality.
--- Bob mailto:[EMAIL PROTECTED] Monday, March 04, 2002, 9:40:12 PM, you wrote: > On Monday, March 4, 2002, at 03:16 PM, Bob Walkden wrote: >> According to my information ("Pentax users guide Z1 etc." by John >> Clements, Hove Books), which may be wrong, the MTF programme "selects, >> when it can, the optimum aperture for the lens in use and adjusts the >> shutter speed to match. [...] If the need arises in order to capture the >> shot, the aperture will be adjusted away from the optimum aperture.". >> It says nothing about chossing apertures in descending order of MTF >> optimality. > Bob, my question is, if the MTF program "selects, when it can, the > optimum aperture for the lens in use" but does NOT use MTF data for the > selection, what criteria DOES it use? And how is it different from the > regular program line? > -Aaron - 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 .
