Video Dark background

Whilst my face is clearly displayed when conducting a meeting, my video background is constantly darkened even though I have set the tick box to adjust for low light. Does anyone have any recommendations as to how to lighten the background. I have also unset the tick box for low light and this does not seem to make any noticeable difference.  

I am using version 6.3.1 on an HP Envy 360 2 in 1 laptop and using HP's inbuilt Truevision 5 MP camera.