At one point McCullin's Nikon camera stopped a bullet intended for him. In his later years he turned his attention to wedding, still life and landscape photography.
The video is long on Canon advertisement but overlooking that it is interesting to see him readily adapt.
When I hand my camera to someone else to take pictures, they inevitably frame their shots by the monitor, it is nice and big and the eye piece so small. That is what the tiny live t.v. camera inside sees, not what is seen through the lens. It ignores the whole point of the awesomeness of through the lens SLR and it's not even actually 100% live due to processing. Fast, yes, but not actually live. The viewfinder is exactly what the lens sees. McCullin remarks people with digitals check the monitor playback after each shot and risk missing action by taking their eye from the eyepiece. I agree. The viewfinder is the way to go, and the monitor useful for framing in those instances when you cannot get your head and your eyeball behind the camera. It is also used to establish and check settings. But once checked there is no good reason to keep checking unless light changes you are still uncertain about settings.