>The advantage of stacking is that helps with motion (a lot)
Yeah, that was my assumption that I didn't articulate very clearly. For the same total exposure time, you wouldn't intuitively expect an average of multiple short exposures to be much different from a single long exposure (all depends on the mathematical details, as you say). But of course if you have a good alignment algorithm, you can often in practice use a much longer total exposure time. Then, to state the obvious, you can use a lower ISO and get less noise.
Is it the case that C_T is independent of C_{pd}? Looking at the (obviously rather idealized) circuit diagram, it seems odd that their values would be entirely independent in a realistic design. I guess I am basing my intuition on the simpler case of reading a single photodiode, where it is undoubtedly the case that the larger capacitance of a larger photodiode makes it more difficult to achieve a high bandwidth. Perhaps 'read time' as such is not the issue. But being able to scale up the individual photodiodes without sacrificing bandwidth seems a big magical.
Yeah, that was my assumption that I didn't articulate very clearly. For the same total exposure time, you wouldn't intuitively expect an average of multiple short exposures to be much different from a single long exposure (all depends on the mathematical details, as you say). But of course if you have a good alignment algorithm, you can often in practice use a much longer total exposure time. Then, to state the obvious, you can use a lower ISO and get less noise.
Is it the case that C_T is independent of C_{pd}? Looking at the (obviously rather idealized) circuit diagram, it seems odd that their values would be entirely independent in a realistic design. I guess I am basing my intuition on the simpler case of reading a single photodiode, where it is undoubtedly the case that the larger capacitance of a larger photodiode makes it more difficult to achieve a high bandwidth. Perhaps 'read time' as such is not the issue. But being able to scale up the individual photodiodes without sacrificing bandwidth seems a big magical.