you will need to manually control the exposure when used. usually a case of putting camera on manual and using the dial to adjust shutter speed to get exposure centred (0), whilst focusing and composing the shot. well in my case that is.
the better cameras have program modes to work with old lenses that do exposure automatically if shooting in shutter priority for example. where as mine (sony a200) once theres no lens sending that info to the camera it refuses to work unless in manual. im not sure if you needed this info but there you go