I think the main advantage of the floating element design is better performance at close focus range ( all focus distances equally good, instead of optimized for infinity for example). jco
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of David Weiss Sent: Wednesday, February 14, 2007 7:41 AM To: Pentax-Discuss Mail List Subject: Re: WTB: Pentax K 28mm f2.0 Lens Didn't know they had that type of design back then, always thought that was more of a modern design. Nice. I notice on Boj's site that the resolution numbers are slightly better for the "m", so I suppose the compromises they made were well done. Perhaps it is not quite as good wide open? As soon as the weather breaks, I am going to find out how it performs wide open. Dave J. C. O'Connell wrote: > The K28/2 was an all out expensive floating > element design which optimizes image quality > at all focussing distances and apertures, > the M28/2 was not. The M28/2 was compromised > for price and much smaller size/weight considerations instead. > > The K28/2 is most unusual for a 28mm lens, > it has a barrel profile very similar to a typical 105mm/2.8 lens! jco > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf > Of Jim King > Sent: Tuesday, February 13, 2007 1:22 PM > To: [email protected] > Subject: Re: WTB: Pentax K 28mm f2.0 Lens > > > David Weiss wrote on Mon, 12 Feb 2007 19:37:42 -0800 > >> I wonder how that [the K28/2] is rated? I have the "M" version of >> that lens. What do you think of the optical qualities of the "M" >> version? Is it more rare than the "K"? > > According to Boz's site, the K28/2 is an entirely different design > than the M28/2, with one additional element, and it weighs almost > twice as much. Takinami says that along with the K28/3.5, it's the > best of the Pentax 28s. > > I have the M28/2 already and if I ever get the K28/2 it will be > interesting to compare them. > > Regards, Jim > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
