It is visibly faster, and quiet enough that
you have to put your ear up to the lens to hear it.
Part of the design of the 16-50 at least is a very short travel for the focus range.
Unlike the oldhand focus that took most of a turn on a helical to find the focus the 16-50 only
moves about a 1" and the positioning is done what appears to be a stepper motor, and is really faster than your eye can figure out that it is out of focus so if you hold the shutter button down (to have it active) and pan from a distant object to a close object your eye won't see anything out of focus even though the mechanics have moved from one extreme to the other.
Likewise if you want to manually adjust the focus because you don't like what the motor did, it has a slip clutch override, andyou can easily turn
the focus ring to manually tinker with the focus if you want/need to.
Just to see the difference I put the lens on my istD, and it works there in the traditional way
but that way sucks in comparison.
I was almost ready to dump my perfectly good istD on ebay until I figured out I had another
problem that I need it for, and that is the Flash
All my flash units are of the older and now unsupported (by the K10) technology.
Where I'm really stuck with with the macro flash.
I have an 080C ringlight flash unit which works as well on my istD as it did on the SuperProgram it was designed to work with, but alas, no work on the K10.
Thus it seems that the istD has to stay around
for macro work, until a macro suitable flash solution appears for the K family of digitals.
And I'm not sure there is a 'macro' solution
Posted: 2007-08-27 18:50:58 #