Lightning Flash ????
 

Hello,

I have been driving my self crazy trying to figure out how to create a realistic lightning flash. I am not talking about the bolt but just the light effect created by a flash. Kind of like how a room flash lights up after a lightning flash, I cannot get this to look correct and think there would need to be an expression or somthing to mimike this natural effect

Does anyone have a tutorial or an expression to create this . Any help would be very appreciated.