Scene depth configuration

Hi Everybody,
I’m new in unreal and i’m interested to use unreal engine for render big resolution in less time.
I would like to use my Z depth for composite my render but the pass look like a tiling gradient in my render.

There is a way to configure the distance of the gradient?

I tried the solution with material scene depth but i’m pretty sur there is a way to scale this gradient.

Thanks for your feed back