Rod, Sorry if this has been asked, but was the 1.2 lens also set to 2.8? Thanks,
Jack --- Rob Studdert <[EMAIL PROTECTED]> wrote: > On 28 Apr 2005 at 0:33, Rob Studdert wrote: > > > On 27 Apr 2005 at 7:16, Shel Belinkoff wrote: > > > > > Isn't a macro lens designed for flat field > work? If so, wouldn't a regular > > > lens used with an extender, a bellows, or > helicoil focusing device, be a > > > better choice for 3D objects, such as close-ups > of flowers or small objects? > > > Or maybe close-ups of not so small objects? > > > > Yes, most dedicated macro lenses are flat field > corrected. If the primary point > > of interest is in the centre of the frame you > might get away with a non-macro > > lens pretty easily but the point is that the > generally distorted plane of focus > > on the subject side of most non-macro lenses can > become a problem at macro > > distances. It certainly would be no better for 3D > objects, a flat field lens > > will generally record any object in close focus > with less optical distortion. > > To provide an example I just produced a pair of > shots at f5.6, one with my > A50/1.2 + tube and the next with my A50/2.8 macro > lens, nothing changed but the > lenses: > > http://members.ozemail.com.au/~audiob/temp/IMGP2269.jpg > 50/1.2 > http://members.ozemail.com.au/~audiob/temp/IMGP2270.jpg > 50/2.8 Macro > > Cheers, > > > Rob Studdert > HURSTVILLE AUSTRALIA > Tel +61-2-9554-4110 > UTC(GMT) +10 Hours > [EMAIL PROTECTED] > http://members.ozemail.com.au/~distudio/publications/ > Pentax user since 1986, PDMLer since 1998 > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
