Scene Capture 2d ortho long distance issue.

I’m working on a program that use the Cesium Plugin to render the world terrain and buildings.
I need to process the depth buffer and the color buffer of a camera in ortho mode to produce a radar like image.

I had success using a couple of SceneCapture2dComponent and a couple of render targets, but…

I had an issue when the terrain distance is greater then 2.5 Km and the Color buffer come out as black ( I had not check the depth buffer in this case).
I place a camera with the same parameters of the scene capture component and make it active when I take the shot ( I had an hunch that the culling could be the issue ) but that still not resolve the problem.

The strange thing is that the camera render an image while in the scene capture component the image is cut by half (where the distance is greater of 2.5 Km).

Any idea or suggestion where to look and what to check to resolve the problem?
There is the possibility to move the camera along the Look At Position line but I prefer do it straight if possible before thinking a workaround!

Thanks in advance!