Fred wrote:
>. I guess that I am as dubious as Mark is as to P�l's statement that >the FA* 200/4 Macro is sharper than the A* 200/4 Macro. If P�l is >correct, then the FA* lens must ~INDEED~ be "truly incredible", since I >have found the A* 200/4 Macro to be the sharpest lens that I have ever >used. The FA* 200/4 ED IF is indeed sharper wide-open. Stopped down I doubt anyone can spot any differences. Both lenses are fantastic though but the FA* is slightly, but not significantly better. >Nonetheless, I am still dubious that Pentax changed to IF for the >FA* lens for optical reasons. Rather, I suspect that the change to IF >was done to facilitate AF (possibly lower focusing inertia to overcome) >and that there ~might~ have even been a willingness by the designers to >accept a slight loss in sharpness as a result - admittedly just >speculation on my part, to be sure. I think its for optical reasons mainly. Eg. the FA645 120/4 Macro is made in the same manner as the A* 200/4 ED Macro with extended metal lens tube. I don't think the AF system would have had any trouble with such a solution. The main reason for the inner focusing design are handling, less vignetting at full extension, less light fall off due to extension in effective aperture, and better working distance. P�l - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
