« on: December 07, 2011, 01:59:22 PM »
...and not give rise to the noise seen in neuroanatomist's images. We have to find the explanation elsewhere...
I believe the issue is that the longer length of time the analog and AD conversion circuits are in use, the more cumulative noise from these circuits there will be imparted on the final image. Remember, circuit noise is a random deviation from ideal performance (i.e. amplitude in the analog domain) and these deviations also have a random frequency in which they occur.
That's true in general, however, the readout of the image sensor and the A/D conversion takes place after the exposure is completed. I'm fairly certain the readout and A/D process would be identical and take the same amount of time regardless of the exposure time.
So the sensor is actually a storage device? There is no way to have a fixed length of time for the analog and AD to be used *regardless of exposure* unless the sensor actually is a storage device as well. I don't see how that is possible but confess it's not an area of electronics I know anything about.