depth blend not displaying

Hello,

I seems to have a problem with the depth blend node. I can't get it to display normaly.

I connected it to the emissision, turned off depth write, assigned the script to change the depthTextureMode of the camera....But i just doesn't display anywhere (game view, scene view, play mode, ...).

The only way I found to display it, is to disable the scene lighting in scene view. But this still only apply to scene view.

Am I doing something wrong ? I tested everything (Deferred, forward,...)