How to calibrate size of displayed objects

I want to show objects which scale is just the same as the Unity. For example, the size of 0.05 in Unity becomes 0.05 m with Looking Glass in real world. My goal is to show a nearly accurate 0.05 m cube not only about width and height, but also depth, as if it existed there.

PROBLEM
The “size” and “Fov” parameters of Holoplay Capture can be used for controlling the scale, but both of them end up changing the scale. Both of them should be changed ?

The thick acrylic plate provides refraction which might cause the change of size and depth.