I am filming video with my Canon Rebel T3i (my lens is 18-55mm, the starter kit one) and would like a big DOF for my footage. My problem is that I have to pick between having a big DOF and my frame being lit poorly (dark) OR a small DOF and my frame being lit well (bright). My goal is to have the frame be big DOF while being lit well.
I am not an expert so I did some research and learned that the ISO, F-Stop, and Shutter Speed affects my situation. I am filming at 24fps which means my shutter speed has to be double that (50). I cannot increase my shutter speed to bring in more light. Since I want a big DOF, my F-Stop value is high (ex. >12) which darkens the frame. I have increased my ISO to 3200 but it already looks grainy so I do not want to increase it more, in fact I want to lower my ISO but it will be almost pitch black.
Can anyone provide me with some solutions? Is there a better lens I can purchase to overcome this problem? Would the most obvious solution to be just buy more studio lights?