2010/1/10 Sandy Harris <sandyinch...@gmail.com>: > I have never used an autofocus system. I find myself comparing lenses > with an SDM motor to ones without. For example, the 17-70 f4 has SDM > but 16-45 does not. 55/1.4 does but 50/1.4 and 70/2.4 do not. > > There are plenty of other differences -- notably price, weight and > focal length -- and I have some idea how to balance those in relation > to my usage and preferences. However, I don't have much idea how > important or useful the SDM motor is, so I am asking here. > > Is this something that should be ignored in making a choice? An > important factor? Somewhere between?
The main benefit of in lens AF motors for Pentax users is how quiet it is. Compared to my Nikon kit, the gear noise from Pentax lenses & in body motors is horrendous. I'd also say it's slightly faster, but I reiterate that the main bonus is near silent AF operation. YMMV DS -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
