- MCC
Yes, fine sense.. As I understand it (I'm an electronics engineer) it is the gain or amplification of the system that is changed... So the sensor has fixed light and produces a fixed output signal.. BUT between the sensor and the digital encoding is an amplifier system (like a pre-amp on a hi-fi). This amplifier has a software controllable gain (volume control= ISO control) to present a larger or smaller signal to the Analogue to Digital Converters which digitize the signal for the internal computer to generate the file.. Just as you get a bit more hiss if you turn the Amp up high so also you get a bit more random signal (Noise) when you set a higher ISO. This noise is partly due to the inherent noise down at the bottom of the sensor signal being amplified more, and partly due to the amplifiers themselves, naturally the bigger the gain (Higher ISO) the worse the problem becomes.. But we lowlighters will begin to see digi-noise just as we see golfball grain.. as a feature rather than a bug! Hope this helps, Tom.
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Mark Cassino Photography
Kalamazoo, MI
http://www.markcassino.com
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