Nikon vs. Canon: Auto-focus speed in Low Light: 50D vs. D300s; 1D Mk III vs.

[ManhattanPrjct]

That works. Thanks.
Humm. With, for example, aperture set wide open, ISO set at max 800, and shutter set at minimum 1/250... when the light starts to get too dark for these settings, will the camera just underexpose, or will the max ISO setting "override" the minimum shutter setting, and lower lower the shutter?

It depends on what mode you shoot in:

- If you're in manual, and you deliberately pick an aperture/shutter that's not centered in the middle of the light meter, you'll get an ISO boost.

- If you're in aperture priority, if the shutter speed the meter picks is below your minimum shutter setting in your Auto ISO preferences, you'll get an ISO boost up to whatever ISO limit you set (when I use Auto ISO, it's when i'm not on a tripod, and it's generally only to 800).

The Auto ISO settings don't limit the slowest shutter speed the camera will pick, just when to boost the ISO to help compensate.