Is ISO a primary control

Probably.

For Ev compensation, I use the custom button on the back, designed for that very purpose.

Interesting thread.

As newcomer to SLR photography, and mostly shooting in the dark, I use the camera somewhat differently to most people - I exclusively use two primary controls - Fixed Aperture and Fixed ISO, and let the camera sort out the Shutter-speed. I then bias with +/- EV and raise/lower the ISO & Aperture as necessary if the image is blurred (often) or overexposed (rarely).

Talking to people who shoot with D700/D3/etc at work they often work in a similar way. Maybe its a low-light shooters thing...

Having an ISO than can be varied from 200 to 6400 gives me a freedom that never ever existed in film, or even digital until very very recently. With it comes a different way of working - the "Holy Trinity" was "one fixed, two variable", now its "three variable" which is almost certainly too much for anyone to juggle in their head, so you have to fix at least one of them! Which one you fix... is down to the individual and what they are most comfortable with and can relate to.

I can relate to the effect F-Stop and ISO have on my picture, I can't relate to Shutter speed. I know this is something I want to work on, and when I get a chance (ha ha...time..) I'll experiment with alternative ways of shooting.

I have two main modes (depending on what I'm doing):

1. Av mode, with ISO+Av on the wheels. This is for normal situations where I'm happy to let the camera work out the exposure, knowing I have some latitude in RAW processing later. Hardly ever use the Ev comp.

2. Manual mode and there I'll use ISO+Av+Tv. I need access to them all through the viewfinder. This is my preferred mode for plays, gigs etc. I'll get a spot meter off skin (using the green button) and adjust all three to suit the particular scene - working out the adjustments in my head (e.g. three clicks on Av + three clicks the other way on ISO). Seeing all three values in the VF is incredibly useful so I can balance everything. In the end I get a 'feel' for lighting changes and can work out roughly how many stops I need to change, or take a reference point for one lighting config and keep coming back to that. Sounds complex, but works a treat.

Matt

No Stefan, you are not alone. I have my K10 set so that the rear dial controls aperture in Av and shutter in Tv. I also use the front dial for exposure compensation.

I dont know if it was because I was brought up on film or because the K10 does not do >800 ISO very well, but I tend to set a fixed ISO (100 or 200) and stick with it until the light is poor and I need to use a higher one.