CamTwist is a FREE broadcast quality TV studio app for Mac. It allows for various effects to be applied to a video source. It then acts as a virtual webcam for other Mac apps to use (e.g. Skype, LiveStream, ProPresenter)
Download CamTwist 3.0
The 3.0 Beta comes with native Syphon support, when using the 2.5 version, you will need CamTwist Syphon ().
Install CamTwist 3.0
Choose Syphon as your input video source and under Settings select your Syphon Client (I’m using VDMX5 with Syphon Output in this example).
Open the app you want to use the Syphon feed as a Webcam
I will use Skype in this example. Under Settings I will find a list of my webcam sources. CamTwist is one of them.