Godfrey DiGiorgi wrote:
On Oct 5, 2005, at 7:25 AM, Adam Maas wrote:
The most important factor is how efficienty the overall system works.
Lens driven AF is more efficient than body driven AF.
I very much doubt that this holds as a general claim.
This is a general truth in the mechanical engineering of servo
systems. Reducing the number of bits between a motor and the thing
being driven always reduces power losses and increases control.
Motors can be made smaller and lighter, lower power, etc.
Yes, but they probably *have to* be made smaller, lighter and lower
power, too. Right, you do save something on a reduction in mechanics,
but you get some new ones in that you introduce power transfer,
switching etc. to the lens (not needing *any* electric connections to
the lens is definitely attractive in many ways), and you also put much
more serious restrictions on the motor size etc.
Also, it seems to me that the bits between the motor and what's being
driven are in any case so few and close together anyway that it doesn't
really matter that much.
- T
