projection by using light when you have certain tissue thickness you're not gonna see see a shadow at all right because light will follow a highly tortuous photon path before reaching your observer right so on this side you won't see a shadow if we surgically cut open a tissue right that's invasive of course now the right hand side is well very well defined because this is all exposed to your error in the photon path will be well-defined allowing us for two form a very good image despite the torch was fallen paths on the left side so the