RE: [Leica] optical excellence and the human error factor

[Austin Franklin <austin@darkroom.com>]

> W.R.T. to EV being used for Autofocus detection capability they are and I
> quote from the owner's manual.

> F5 - "Autofocus detection range EV-1 to +19"
>         " Metering range EV0 to 20 in 3D colour Matrix, EV2 to 20 in 
spot"

> EOS 1V " AF working range EV0 to 18"
>                " Metering range EV0-20 for all metering  modes"

That's all well and good, but these are numbers that for optimal conditions 
for the particular system the manufacturer has deployed.  The actual real 
world range of the autofocus system can vary considerably from the numbers 
you (they) quote, depending on scene conditions.  Metering is completely 
different, and is far more accurate to characterize and give a spec for.

If you want to discuss this further, perhaps you ought spend some time 
learning how the different systems work, and what their shortcomings are. 
 I have used many autofocus (and autoexposure) systems, and I have found 
shortcomings of every one in real world situations.  If you understand how 
the particular one you are using works, you can then understand how best to 
use it, and avoid possible situations that will cause that system to fail.