I found the reason and solustion.

The visitor, and settings, are based on ground level a zero.
So the "Eyes Elevation (cm) calculates from that.
As my piscure should be from a outside surface at the sam level as the house basement floor witch is ground level -250cm, i had to calculate the "Eyes Elevation" based on that.
0 - 250cm+160cm to get eye hight of a person standing outside the basement level of the house.

Thank you all
Thops