I have heard that I should not use the as-15 with some studio flash systems (I have Novatron) there could be damage to the D-100 from the flash unit in the form of voltage. Does anyone know if this is true? I was told to buy a Wien Cat. No. 990-500 or Cat. No. 990-550 Safe-Sync to protect my camera's contacts at 3 times the price of the as-15. For now I use a photocell (peanut) and trigger with my sb-24 set low power and the head turned around backwards.