Hi there! I am interested in going for light pigmentation therapy in my face. I am seeing a therapist using IPL and am sceptical of what setting should be used. Its measured in Joules right? So would 30 j/cm2 be safe enough to treat this or should it be higher? I dont want blisters etc in my face, I do understand that darkening should occur, what would you suggest? The lense to be used - must that be a specific colour or is a 640 mn lense right? I am a medium skin colour.