I'm struggling to be able to use one webcam input through two different gemheads.

Ie, to mix together two different versions of video from the same webcam input.

Anyone have any tips?

Cheers

Can you just split (with a trigger if you like) the gem chain and then use a [pix_separator] on each "branch ?" If that won't work, try [pix_buffer] ing the cam feed and pulling from the buffer in discreet GEM chains.