When to use Live View and when not to use Live View
There’s no getting away from the fact that the contrast detection systems employed by most DSLRs when they are in live view mode aren’t as fast as the phase detection systems that they use when images are composed in the optical viewfinder.
It is also often possible to select to use a camera’s phase detection AF system during live view, but this is often a slower process as the mirror has to flip down and interrupt the live view feed.
As a result, live view isn’t usually a good choice when you need to focus quickly and/or the subject is moving.
It’s also fair to say that when you look through the viewfinder the camera is usually held more steadily than if you hold it out to see the LCD screen on the back of the camera.
This is because the camera usually rests against your face and your arms are tucked in against your body when you look through the viewfinder making an effective brace.
These points mean that live view is often best reserved for shooting stationary subjects and when the camera can be used on a tripod.
This makes it ideally suited for use when shooting still life, macro and landscape subjects.
It can also be useful when shooting portraits as, just like a waist-level finder on a medium format camera, you can maintain eye contact and chat with your subject without the camera getting in the way.