The discussion can get pretty complicated, but yes, as the amplification electronics improve, we are approaching an ISO-invariant situation.
In short, when you raise ISO, all you are doing is raising the amplification of the signal off the sensor, you are not changing the sensitivity of the sensor in any way. So with a perfect amplifier, it should not matter what ISO you actually shoot at. Now, that said, there is a trade-off for shooting at high ISO, and that is reduced dynamic range. As we amplify the signal more to bring up the dark areas to desired brightness, we will inevitably blow out highlights. This is what the linked author saw in his tests. It forces us to conclude that shooting at a lower ISO and bringing up in post can actually result in more information retained. |
