The glass showing inside the retaining ring on the M35/2.0 is almost exactly one inch. The barrel is bigger than the Summicron's due to the larger diameter mount. Considering that the M35/2.0 is a slight retrofocus design it is amazingly compact. Also remember that the aperture on a 35/2.0 is only 17.5mm considerably smaller than the aperture on a 50/1.2 or 1.4.
-- graywolf http://www.graywolfphoto.com http://webpages.charter.net/graywolf "Idiot Proof" <==> "Expert Proof" ----------------------------------- Shel Belinkoff wrote: > I'm talking about the lens diameter, not the barrel diameter. For example, > the diameter of the front element of my 35mm Summicron (f/2.0) is about > 1-inch while the front element of my Pentax 35mm f/2.0 is 1.5-inches. I'd > be curious what the diameter of the front element is on an M or A 35mm 2.0 > ... anybody got that figure? > > You mention "later design." That implies that the lens diameter (just the > glass) is smaller than earlier models. If that's the case, then it should > be possible to design a smaller diameter lens for a DA than for film - at > least that's one way to look at it. > > Shel > > > >> [Original Message] >> From: Adam Maas > >> 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. > > > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
