3 times slower is ridiculous at best. can he back that up with numbers?
Quote: I am wondering why this is so and what Pentax has to say about it. Isn't it a confession of failure that an almost 20 year old lens focusses so much faster?
not this again.... refer to thread posted above. another joker who likely thinks SDM should be as fast as ring USM... and taking absolutely nothing other than its newer into consideration...
they aren't the same lens, so why compare AF speed between the two anyway? makes no sense.
speaking strictly of the mechanics. the FA50 and the DA 55 are two completely different lenses. less glass elements in the FA. the FA is also smaller and lighter. (due to less glass, lack of on board motor, weather sealing, and the electronics associated with the auto/manual switch etc.) furthermore SDM does NOT equal faster focusing. I doubt it would be any faster if it was screw-driven compared to the FA. such ignorance.