But you're still basing your agument on the (apparently unwarranted) premise that the *ist-DS *does* disable TTL flash for all non-AF lenses. According to other posters here, that simply isn't the case.
As I said, people are far too fast to accuse Pentax of deliberately disabling bodies for the sole purpose of selling new lenses. Peter J. Alling mused: > > John you're right and you're wrong. If the lens tells the body the > focus distance, that would be usefully for > helping calculate the flash duration, disabling TTL flash with lenses > that don't support sending distance > information to the body has two purposes, and one is the sale of new > lenses, the other is the assumption > that the user is incapable of a rational decision. The better solution > would be to make the user aware of how > the body calculates TTL flash exposure and allow the user to make a > choice, not force one on him. > > John Francis wrote: > > >Jens Bladt mused: > > > > > >>Kostas wrote: > >> > >> > >>>I believe it was > >>>mentioned previously that on the -Ds it does not do TTL if you don't > >>>have an AF lens. This is a limitation induced with extortion in mind, > >>> > >>> > > > >Why are people so fast to make unfounded accusations like this? > > > > > > > >>Is this really true! What would AF have to do with flash duration? > >> > >> > > > >Distance, distance, distance. > > > >The digital contact (introduced on the AF lenses) doesn't just tell > >the camera body the lens identification code and current aperture > >(and focal length, for zooms); it apparently also reports the focus > >distance. While there is no official confimation from Pentax, it is > >believed that the metering logic makes some use of this information. > >(Nikon, of course, made a big feature of their 3D Matrix Metering, > >introduced at about the same time. Pentax don't even mention it). > > > > > > > > > > > -- > I can understand why mankind hasn't given up war. > During a war you get to drive tanks through the sides of buildings > and shoot foreigners - two things that are usually frowned on during > peacetime. > --P.J. O'Rourke > >
