1. The factors that control motion blur in photography are the decrease of shutter speed, smaller aperture, reducing ISO setting, lighting, and finally camera stability. Above all else the most important factor for capturing motion blur is shutter speed for example a fast shutter speed will freeze motion, while a slower shutter speed will cause the subject to blur.
2. The most important factors in photography the affect depth of field are aperture, camera to subject distance, and focal length for me specifically I had to get real close to my subject in order to create the affect of shallow depth of field.
4.In the two pictures of Samuel Jackson the one in color you can see the photographer was using split light for this picture because it shows his face in two equal halves. For the picture in black and white the photographer was using butterfly light. so that the subjects face is well lit. In the photograph with color the photographer is using the technique leading lines he is using arm of the glasses to have the viewer lead his eyesight to the face of the subject. And finally for both pictures the photographers used centered composition in order to have the main subject be the center of the frame.