>> >> Nice in theory anyway.... Of course, in the real world the linearity comes >> in to play as you say, but, as discussed previously, theres a point where >> sensor noise makes more bits basically meaningless. >> > > Yes, you have to distribute your bits between the noise level and the > saturation level. Some things, like an increase in the light sensitive area > of each pixel or other tricks like reducing dark current, can suppress noise > in one ends and other tricks like Fuji does with their sensors may give > something in the other end. Wouldn't an increase in the light sensitive area essentially mean increasing the native ISO? I mean, the absolute noise and even noise relative to saturation level would be the same, but saturation would be reached faster. > In addition you can gain a little bit in how you distribute your bits, and > maybe that is what they do in the 22bit conversion. > It's been mentioned before, but based on some info Rob Studdert dug up, I'm lead to believe that there aren't any extra tricks involved in those 22bits. It's probably all about a circuit designed to work with different types of sensors, that *for internal use* converts the signal from the sensor to a digital value with so many bits that you can be pretty sure no information (not even the noise) is lost, no matter what sensor you throw at it - and probably also so that calculations that involve multiple steps won't loose accuracy between the steps (think of what happens if you do a division followed by a multiplication on a digital value.) It will do various types of gain/offset adjustments in this domain rather than on the analogue signal so as to make sure no *extra* noise is introduced (the original noise may still be amplified, of course.)
- Toralf -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
