I indulged in a bit of mischief on the reduser.net forum with this same question and the linked clip. What do you think it might be? The camera system has been chosen to be used in conjunction with a Panasonic 35mm sized sensor camera for a low budget music video.

A small clue. The lens used is the Nikon 50mm f1.4 at f2.8 at f2.8 with ND.3 frame rate, 25P.

OVERCAST TEST - YouTube

And the answer is...? Please...

One of them DVX100 Andromeda setups? Or the SI2K...

Sony PMW-EX1 with Letus Extreme 35mm adaptor and Nikon 50mm lens, which was probably a bit cheeky of me to be posting on the reduser forum, especially given that I do not own or operate a RED.

They take my occasional bit of pot-stirring over there in a good-natured way.

As for the music video, the director ended up using the SI2K for the wide lens on a dolly and the Panasonic for the closer views and steadycam bits.

What Panasonic has a 35mm sensor?

I don't know what model. One of the crew said it was a Panasonic. I think it is one of the cameras that has a sensor of similar size as the Canon 7D, not S35. If you are fast enough you will see the camera in this BTS clip, also shot with Letus 35mm adaptor and EX1.. It makes a nice image. The owner was using Nikon lenses on it, mostly a wide-angle zoom.

BEHIND THE SCENES. MUSIC VID. - YouTube

The visual theme of the clip was the lead singer morphs back into his childhood self after a heavy party the night before. The clip is apparently now on Youtube. I shall find out the web address and post it here.

Panasonic AG-AF100. There's a very clear side view of the camera @ 0:54 of the BTS clip.

So it's u4/3rds.

After all this time, I have just realised that I failed to link to the finished music video.

Here it is.

Only Love Things - YouTube