One set. I'd like to set the iso quite low, say 50 or 64 and the aperture on the sweet spot, probably 4.5, and let the shutter speed fall where it will. This, I would use for bright days, which is mostly what I do. .... john
Well, you can almost do what you want by setting up those values in the Enhanced Photo Operations menu and the using the
Half Shutter plus
Down keyboard shortcuts to enable / disable them on the fly.
Although you probably won't get much below ISO 80 IRRC, regardless of what you set the CHDK value to.
But there's a problem. When you set exposure value overrides with CHDK, you really need to set all three ( Tv, Av, Sv ). If you only set one or two values, then Canon firmware will set the other ones with values based on its desired settings for the ones you overrode. Which means the resulting exposure will almost certainly be wrong. (i.e. the Canon firmware does not know CHDK is overriding some of the exposure values and does not adjust its calculations to compensate).
Which means that you need a script to keep track of everything and do your shooting for you if you want a Tv, Sv, or Av priority mode. There are quite a few of those available.
