unity camera have distortion of perspective?

Hello there

I'm trying to create some kind of AR for testing and meet such problem, that unity camera have distortion of perspecive in reference with real webcamera .

For test was created cube (with transparent material) that have exactly same size as real htc vive box and using all unity camera settings do not allow us to make all 4 angles of 3d cube perfectly fit to real htc vive box. On image below you can see 2 our best setups, but always 1 angle do not fit by distortion issue.
https://imgur.com/1Za6fzk

Webcamera record in 640x480 - same size plane, where we send video stream.
Already try "Physical Camera", that in theory should solve this problem.

So question If i able somehow to change perspective properties?

Thanks