Consider that the camera is in shutter priority and the exposure time is set to bulb mode. Now the camera doesn't know how long the shutter is going to be open in advance and so how does the camera ...
So what's the benefit of using one over the other? The way I understand it, in Av or Tv, you only have to adjust the shutter or aperture, and the rest is done automatically for you...is this correct? ...
What do the T and v stand for? Public-domain image from Wikipedia.