Auto ISO in 5d Mk II

I'm opening this up in a separate topic from Roy's Auto-ISO topic because I want to ask a slightly different question from his, and not pollute his topic. Anyway:

Reading the 5D Mk II instruction manual, it tells me that in "Av" mode, Auto ISO will automatically vary the ISO between 100 and 3200.

Of course, Av mode allows me to set the aperture and let the camera choose the appropriate shutter speed.

My question is: given that the camera now has two things it is free to juggle (ISO and shutter speed), how does the camera make the choice? Is this information published anywhere?

regards,
/alan

About to go and visit the MagicLantern site to see whether they have a good implementation of AutoISO for M mode...

The Magic Geni inside called the camera logic board decides ..
http://www.dpreview.co​m/forums/post/29399060

Seems liek nobody knows the actual algorithm used Thanks anyway

I can't find anything useful in Magic Lantern either...

That's pretty much it.

I'm thinking I might try that next time I am shooting in a theatre... thank you