With an HF10 (or any of the HF's for that matter) set to either "Program AE" or "Cine Look", is there any way to determine what shutter speed the camera is chosing? The reason I ask is that it would be helpful to identify the light level that starts pushing the camera above 1/60 - one could then add an extra external ND filter to supplement the internal ones.

(I realize there's a Tv mode, but that gets disabled by Cine Look, which I like for its gamma curve).

There are no camera settings metadata that can be inspected in the avchd clips themselves, right?

I don't believe it records that data that you can check out later. My only suggestion would be to shoot in Tv mode and add the "look" in post.

Cine Mode should be using the widest aperture with a shutter speed around 1/48 - 1/60 if possible.. you could try switching to TV mode and choosing the correct shutter (and using a zero gain setting if you have one), then playing with the light until everything looks good, and then checking in Aperture mode as well. Switch back over to Cine Mode and it should select the correct shutter (or as close to 1/50 as possible). This is the only solution I've been able to come up with, and is still a bit of guess work as in TV mode the camera automatically adjusts aperture, and so on..

However, it could be that cine mode will over-ride any settings you've made in other modes - and there's no way of knowing...