CaMus2 allows collaborative performance with mobile camera phones. The original CaMus project was extended tosupport multiple phones performing in the same space andgenerating MIDI signals to control sound generation andmanipulation software or hardware. Through an opticalflow technology the system can be used without a referencemarker grid. When using a marker grid, the use of dynamicdigital zoom extends the range of performance. Semanticinformation display helps guide the performer visually.