Double Images, is it a Shutter issue?

[illcamaras]

Dear @ Arri,
reviewing a shoot we found some clips with an evident double image problem, I don't understand where it come from.
It looks like a shutter issue.

Camera Specs:
APR4444_1800p25
50fps @ 180deg
Cooke S4 40mm @ T2 1/3
SoftFX 1/4

Here a couple of frame grabs.

Anyone with a reason for this?

Thanks
Carlo

[Jan Heugel]

Dear Carlo,

erm.. liik like I missed that...
What kind of lights did you use above the dancer?

Please pm me if you're able to share one of those clips for us to look at.
I'll provide an upload link.

Cheers,
Jan