Creating particles using scene depth

Hi, I’m creating fire particle system, using Scene Depth. What exactle am I doing: the farest particles need to be red, middle - orange, nearest - yellow. And I need this system to be working in different camera position, but i’m getting the results that i need only with one camera position! Can someone please help how to maintain the depth range that I need for calculationsalt text

Maybe you need Pixel depth to measure that range. Scene depth measures range behind target, not to it.