Originally posted by IchabodCrane I agree which is why I don't understand what this K-30 "AutoISO in M mode bug" mentioned in post #259 and #284 is all about. Mine appears to work just as expected.
Historically M mode meant no change to ISO. Of the trifecta for exposure, ISO was not user defined but (literally) defined at the Kodak factory. You could change it, but off manufacturer spec, and pretty much the same as EV. Dead wrong for most slide shooting, but OK for colour negs.
With digital, there is no consensus that M mode from any manufacturer means ISO should not float or be fixed. Floating is actually more traditional from the user perspective because aperture and shutter speed are all they had available anyway.
Pentax digital saw the floating ISO as a mode unto itself, so TAv. In Pentax digital M mode is more rigid (and IMO complex) because now you have to worry about 3 exposure settings and not just the traditional 2. So for users who want it, M mode is now configurable to emulate TAv mode.
On the K-30 M or TAv mode with twin dials appears ideal. Now look at the Ricoh GR where ISO has the rear dial to itself. Hmmmm......
Nothing has changed photography more (since the advent of AF) than digital's floating, fungible, ISO.
One thing I liked from my MZ-S (sadly, sold) was the ability to lock the minimum shutter speed regardless of mode on a separate switch.