Digital BW, The Print

Roy Harrington wrote:


> E.G. with a 12 bit integer value the biggest ratio you can represent is 4096/1.
> If you want a larger dynamic range ratio than 4096 you have to have more bits.

The biggest ADU *ratio* you can represent is 4096/1. But the actual 
dynamic range this ratio represents depends on the number of electrons 
per ADU.

For example, isn't ten electrons per ADU (=0 to 40,960 electrons) a 
smaller dynamic range than 100 electrons per ADU (=0 to 409,600 electrons)?

Another way of saying this is at what electrical potential does the ADC 
output 2048 ADUs? Would that be 10 millivolts? 50 millivolts? And how 
much is the well potential amplified, anyway?

Without *also* having this data, you do not know how much dynamic range 
is represented by a given ratio. I'm all for increasing the ratio. But 
I'd like to see the dynamic range detectable by the sensors increase, too.

--
Jeff Medkeff
Eagle River, Alaska