Limit e-gain but stay in AE mode?
 

I make wedding videos. It was not the first time that i like to use my camera so:

- NOT to use +18db, because the picture is too grainy for me
- BUT stay in Auto Exposure mode, because when going from lowlight place to a brighter place quickly (switch the lamps on, etc..) i cannot change my camera so quickly.

So is there any solution to stay in AE mode, but limit the electronic gain up to 6 or 12 db?
(i think sony cameras can do that?)