Shel, They are, because they have a far simpler aperture design. No aperture coupling or full-aperture mechanism is required for an RF lens, not to mention a smaller-diameter mount (which allows smaller-diameter barrels). But even so, fast RF glass isn't all that much smaller than a Pentax 50mm f1.4 of SMC-M or later design.
-Adam Shel Belinkoff wrote: > I'm not sure that's correct ... I'll have to check the diameter of my Leica > glass. It seems to me that the lenses for my Leica, compared to the same > focal length/aperture of my Pentax glass, are smaller. > > Shel > > > > >>[Original Message] >>From: Adam Maas > > >>Because you need a 35.7mm diameter front element for a 50mm f1.4, or a >>41.6mm front element for a 50mm f1.2. > > >>>Why couldn't they make a smaller 50/1.4? > > > > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
