On Mon, 13 Nov 2006 17:53:18 -0000, John Francis <[EMAIL PROTECTED]> wrote:
> > Personally I think there are a lot of unrealistic expectations > about lenses for a DSLR being smaller and lighter than lenses > for a 35mm film camera. > > There will, of course, be some cases where the smaller sensor > area allows a lens with a given focal length to be noticeably > smaller, but these will be in the middle focal length range > (say 28-70mm), where the size of the lens mount probably makes > as much of a contribution to the physical dimensions of the > lens as does the optical design. When you get out to the > extremes there are other isses that will dominate. > > The big size benefit I see from my *ist-D is that now I can > carry a 200mm/f2.8 where I used to carry a 300mm/f2.8. That > makes a significant difference to the size and to the weight. And to the cost! John > On Sun, Nov 12, 2006 at 04:58:41PM -0800, Godfrey DiGiorgi wrote: >> The difference in design is more than simply angle of view and image >> circle. Lenses designed for a digital sensor have to work hard to >> 'straighten' the light path so as to be close to orthogonal to the >> sensor, something that was never an issue with film. This means a >> more complex design, particularly for the ultra wide angle lenses, >> which adds elements and bulk to the lens assembly. >> >> Godfrey >> >> On Nov 12, 2006, at 2:29 PM, Shel Belinkoff wrote: >> >> > Maybe ... I don't know. But, the Olympus Zuiko 21/2.0 was for full >> > frame, >> > weight but 250 grams or so, and used 55mm filters. Compare that to >> > the >> > A20/2.8 or even the K20/4.0. The Pentax M20/4.0 was quite a bit >> > smaller >> > and lighter than its predecessor. The pentax M85/2.0 is substantially >> > smaller than the Leica 90/2.8 Elmarit, and the Leica Tele-Elmarit >> > 2.8 is >> > smaller than either. The Pentax M35/2.0 is substantially smaller >> > than the >> > K35/2.0. >> > >> > So, why couldn't a modern 14mm be a lot smaller than an earlier 15mm? >> >> >> -- >> PDML Pentax-Discuss Mail List >> [email protected] >> http://pdml.net/mailman/listinfo/pdml_pdml.net > -- Using Opera's revolutionary e-mail client: http://www.opera.com/m2/ -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
