Originally posted by Smeggypants .... but surely a sensor is ISOless anyway? After all isn't the ISO setting an applied amplification ( either before or after the AD convertor?
When I wrote "sensor" I meant to include the analogue amplification and A/D stages.
What I see the "ISOless" proponents saying is that analogue amplification will soon be a thing of the past.
They might also be saying that an "ISO setting" is not needed as way to control a camera. They could do your "base ISO" and push in PP approach right now but would have dark previews and would have to apply initially unknown amounts of exposure push in PP.
Given a way to tag an image with the intended exposure push, previews will be as intended and PP would start from the intended exposure as well. In contrast to the current "ISO"-approach, the full dynamic range would be kept intact as the RAW data would not be scaled by the camera.
I'm fine with the above concept but am not sure whether ISO control will disappear from cameras as it is an intuitive way of communicating an exposure push to the camera that is independent from aperture and shutter speed settings. If one only had a single "exposure compensation" control then one would have to tell the camera what do do with it, i.e., change the shutter speed when in Av mode or just the change the exposure push, or both. In a way the "ISO setting" seems to be a good way to provide intent for some forms of exposure compensation.