Instead of spending my day on my "day job", I've started down this rabbit hole (thanks Greg
). I did a few experiments with the IQ4/Cambo combo with X-Shutter. I spend most of my time in manual mode and often manually meter when I use the Cambo. It tends to get me where I want very quickly and with a great level of control. Sometimes though I do use the raw histogram/clipping bars and so took my own challenging scene at ISO 50, f16 and letting shutter speed float - bright white wall (metered at 1/125s). shadow area, and an area that metered around 1/30 - 1/60 and bright blue sky, which I did not meter. I manually exposed at 1/80 which worked well as my baseline. Then I tried the following:
(1) "Auto exposure" - maybe I don't understand how it is supposed to work but that was rubbish - over exposed by 2+ stops. Surely I was doing something wrong there.
(2) The ETTR lab feature - it chose 1/100 of a second - again, not sure if I had it set correctly (no real docs) or if it is even supposed to work on this particular setup - but unlike the XF, it does do something and it was close, though I wouldn't call what it did "exposing to the right" - quite the opposite. When I've tested this in the past, it will mostly ETTL and maybe 1 or 2 times out of 10 actually ETTR - seems to be very scene specific but not sure of the exact elements that make it work.
(3) Live view, Manual exposure - just used the raw histogram, clipping indicators and not the RGB histogram. The shutter speed before the raw histogram showed any clipping was 1/80 of a second, what I'd chosen above. 1/60 showed some clipping both in the raw histo and the clipping indicators but did not clip in C1 (other than a warning on a few small areas).
For me, in this scene, using live view, manual exposure, raw histogram got me closest (other than metering the scene manually). I'll poke around on it with some other scenes later.
Cheers,
Ray