----- Original Message ----- From: "Peter Jordan" Subject: Re: Introducing the remarkable new Pentax *Ist D
> It says in the press release, "The image circle in the DA-series lenses is > designed to perfectly match the size of the CCD (23.5mm x 15.7mm) > incorporated in PENTAX's digital SLRs, optimizing the performance of these > cameras." > > My reading of that means that the image circle will be smaler than the > dimensions of 35mm film, meaning that they can't be used on film bodies. > > Am I missing something here or is this the end of backwards compatibility? It means that the DA lenses won't be usable on film cameras, unless you don't mind some vignetting. In some respects, it makes sense to have lenses specifically for the digital format, in others it doesn't. From a design POV, they can make quality lenses cheaper for the smaller image circle, since it is easier to make a good lens with a smaller circle. Thats why lenses like the FA77mm only cost a thousand dollars, while a Rodenstock 210mm of similar quality for 4x5 costs a few grand. I can't see the lenses being any smaller, since they are still K mount lenses, and there are size restrictions based on that. William Robb
