It was all inspired by something Joe McNally conjured up, with perhaps more than a little help from our very good mutual friend Justin Stailey (formerly of Bogen, now of Leica USA)
I love shooting tethered for many reasons, it enables me to control EVERY minute element of the shoot from a my camera position, lighting and critically when I'm using my Phase One P45+ , focus...my goodness when it is sharp it is SHARP and when it is out it is OUT big time!
My assistants and I refer to it as the 'Helm' (as in the Nautical world)
It means it is off the floor and out of any mud and dust enabling me to keep eye contact with my subject, which is the very essence of a shoot.
It is a Gitzo/Manfrotto Hybrid
Now,I use a Gitzo GT5660SGT, I admit not the cheapest tripod in the world, but this set up works on any good sturdy tripod too
The cross bar is a Manfrotto 131DDB.
I have mounted a Manfrotto 468MGRC2 Hyrdrostatic ball head on each end, as you can see in the pic it enabled me to shoot tethered with my Canon 5d mk1 in Capture One Pro on my Lenovo W700, while I was using my Canon 5d MK2 for 'b' roll 1080P HD on the other end
If the set up is way critical I switch one of these tripod heads out for a Manfrotto 405 geared head....not cheap but wonderful.
And finally the Gitzo GO65 laptop platform, I recommend putting some self adhesive Velcro on the base plate of the Laptop and the platform just in case....
It really does work a treat!