No, you may also say that the D-FA lenses differ from DA lanses in that they have aperture rings. If USM lenses do not give AF on older cameras I do not think they will have aperture rings, even if they cover FF.
DagT Den 2. sep. 2006 kl. 20.45 skrev David Savage: > The significance of DFA lens is that they cover the 35mm frame. Not > all the DA's do without vignetting. > > Dave. > > On 9/3/06, John Francis <[EMAIL PROTECTED]> wrote: >> I thought a significant difference between DA and DFA was the >> presence >> of an aperture ring. Sure, longer focal lengths are going to >> have an >> image circle larger than an APS-sized sensor. But that in itself >> isn't >> enough to make it a DFA lens. > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
