On Aug 19, 2007, at 10:26 AM, Patrick Genovese wrote: > I'm going to be needing a long telezoom approx 400mm at the long end > for nature photography ... the 50-500 seems to be very popular for > this type of photography. How does it compare with 100-300 + 1.4x TC > combo ?
Not that I trust Sigma lens quality control any further than I can drop one, but there seems to be a reasonable consensus from users on Pentax, Olympus, Nikon and Canon forums that the 50-500 is a decent performer. Not as much information about the 100-300 that I've been able to find. Regards the teleconverter to K10D data interface: - Pentax-A Rear Converters do not transmit any focal length information at all so you can manually set a focal length for the AntiShake system ... they will show up in the EXIF data as Pentax-A series lenses with the focal length you set. Nor do they support autofocus. - The Pentax F 1.7x AF Lens Adapter does translate the focal length and runs its own form of autofocus, which may or may not work with the big Sigma zooms. - None of the other Pentax KAF compatible teleconverters I've talked to people about translate the focal length. And there's no mechanism to set the focal length manually at the present time for the AS system. Godfrey -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
