Rob Studdert wrote:
On 4 Oct 2005 at 9:18, Toralf Lund wrote:
USM is just a *name*. Complaining that Pentax doesn't have it is just
silly. I think I'll quote Tom, here
If you are all conversant with the Canon USM and Pentax body driven focus
technologies then you'd know quite simply it's not just another way to do what
Pentax does. Frankly there's nothing particularly smart or appealing about
driving lens focus from a motor in the camera body.
Except, perhaps, you have one motor instead of one in each and every
lens? Seems more sensible to me... And if you update the motor, you'll
see an improvement for *all* lenses.
Does it matter, anyway, where you put the motor? Aren't the most
important factors in an AF system what the sensor does and how you
process its data - and how fast you do it?
Their technology is
cumbersome and dated
The motor-in-body and motor-in-lens are different solutions introduced
at the same time, as far as I know, so "dated"?
and isn't noteworthy enough to be able to support a
technology label as a marketing tool or otherwise. If Pentax had some fast,
quiet and efficient AF system with a similarly silly name to USM there would be
something to compare.
I must admit that although I've tried some of the never Canons and
Nikons, I've only shot a couple of pictures with each. I wasn't
immediately struck by any important differences in the AF, though.
Quieter, perhaps, but "more efficient"?
- Toralf
