Slow capture with bad lighting

edit

Hello,

I have a program that recognize face features. It normally runs at 33ms. However, when the room is a bit dark, ir runs at 60ms or even 120ms.

I guess that when lighting conditions are bad, some kind of auto exposure kicks in and slows down the capture process. How could I turn this off ? I tired capture.set(CV_CAP_PROP_AUTO_EXPOSURE, 0); but it did nothing.

Thank you so much for your help,

Alex