On Sat, Sep 16, 2006 at 01:28:26PM -0400, Mark Roberts wrote: > Ryan Brooks wrote: > > >Adam Maas wrote: > >> At f2.4, the 70 is about perfect for me. Essentially the same length and > >> speed as the legendary Nikon 105 f2.5, which is a superb portrait lens. > >> > >You are getting more DOF with the 70mm though. > > Not true. Not at the same subject magnification, anyway. (And that's > what you'll be doing if you compare both lenses as portrait lenses.)
Actually, Mark, Ryan is right. A portrait taken with a 105mm lens at f2.8 on a full-frame camera will have a shallower depth of field than the same portrait (taken from the same spot and enlarged to the same size) made with a 70mm lens at f2.8 on a body with a 1.5x crop factor. You'd need a 70mm/f2 to get a DOF that matches a full-frame 105mm/f2.8 -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
