Viewport Exposure contol

Hello,
New rhino 6 rendered view is cool.But…
Is there a way to controll exposure in rendered view?I see only gamma contorol in rendering tab that is effects viewport and few other( i am sorry to say that but) pretty useless options. Is there a way to controll brightness of viewport?
P.s. I need final look brightness , not light values!

I’d like to know too.