Tracking mark on faces - DP Rodrigo Prieto's interview

[Mathew Collins]

Hi,

In the following interview DP Rodrigo Prieto says at 1.52 minute" Martin Scorsese didn't want

tracking mark on faces. That is the reason for witness cameras. Those cameras

were capturing only infrared, and tracking marks were only visible in infrared."

Could someone know this technique and what is DP talking about?

-Mathew Collins

 

Edited December 2, 2019 by Mathew Collins
Modification

[Manu Delpech]

There is a lot of coverage on the film out there, but basically, the two Alexa Mini witness cameras capture the depth and the tracking marks on the faces track the actors' performance. The Red Helium in the middle used as main camera. There was also a specific type of lighting rig, I don't remember the name of it to aid with the VFX capture. What Scorsese didn't want was the kind of performance capture rig you usually see with the helmet, the cameras in front of your face, etc.

[Mathew Collins]

4 hours ago, Manu Delpech said:

There is a lot of coverage on the film out there, but basically, the two Alexa Mini witness cameras capture the depth and the tracking marks on the faces track the actors' performance. The Red Helium in the middle used as main camera. There was also a specific type of lighting rig, I don't remember the name of it to aid with the VFX capture. What Scorsese didn't want was the kind of performance capture rig you usually see with the helmet, the cameras in front of your face, etc.

Could you explain about " tracking marks on the faces "?  What is that used for?

[Manu Delpech]

I did. It's to capture the facial performance, the performance itself, otherwise there is nothing to work from. It's similar to performance capture.