Graystar, how do you reconcile GL's results showing reduced noise at higher ISO?
I think the era of such cameras is nearly over. Certainly there are no longer any APS-C cameras that behave that way, and when all the new full-frame cameras come out this/next year, no current camera will behave as such (well, maybe MF cameras.)
Anyways...remember that in those sample shots the light collected was the same in both cases. the problem with such cameras is that the gain from more light is offset by a loss due to increased read noise from the lower ISO setting. However, there’s still a gain. So it’s always worth shooting at the lower ISO to collect more light. If restrictions on your exposure settings limit the amount of light you can collect and your particular camera benefits from using a higher ISO, then go ahead and use a higher ISO to push the histogram to the right as far as can safely be done. But you can’t call that ETTR for maximizing signal, because you’re not collecting any more light. It’s just exploiting a quirk of the system to minimize read noise (which should have been minimal to begin with, as it is with all the new cameras of the last couple years.) So the two techniques of ETTR to get more light and increasing ISO to reduce read noise really have nothing to do with each other. More light always trumps read noise quirks, which is why ETTR only makes sense at the lowest ISO.
