Hi Richard,
I can only speak as of a couple years ago when I tried last, but HDMI wasn’t supported then, and I’m pretty sure it isn’t supported today.
The Black Magic studio 2 card, for example, supports HDMI recording with its own software/hardware, but Onlocation will only see Firewire inputs.
If you really wanted to spend $700.00 bucks, you could get an HDMI to Firewire converter. The only problem is that it’s HDV, and you would neither get true realtime preview, nor lossless capture.
Vince Becquiot
Kaptis Studios
San Francisco – Bay Area