Designing a Sensor

[John Francis]

On Wed, Nov 01, 2006 at 08:44:57AM -0000, John Forbes wrote:
> On Wed, 01 Nov 2006 04:02:45 -0000, J. C. O'Connell <hifisapi at gate.net>  
> wrote:
> 
> > My guess would be the sensor "base" speed is the speed
> > At which no extra light ( slower sensor speed ) will improve
> > The image quality any signifigant amount. No sense in
> > Going slower if it doesn't improve anything.
> 
> If you are shooting with studio flash, and can't turn it down low enough  
> to give you short DOF, then there is a very good reason to have lower ISO,  
> whether or not it improves the quality.
> 
> Same goes for bright daylight.  It's purely a theoretical concept in the  
> UK, but in  other countries one wishes one could reduce the light  
> intensity at times.

Indeed.   Shooting in full California sunlight with the *ist-D can be a
problem if I want to use a shutter speed below 1/100 for motion blur
(heck, there were several occasions when I found Provia 100F too fast).
It's also a problem if I want to shoot at f2.8 or wider to control DOF.
I welcome the appearance of ISO 100 on the K10D, and would like to see
ISO 50 once sensor technology makes that practical.