Why don't serious photographers use live view more often, considering how useful it is?
By "live view," in this post, I mean, "live view on the camera's rear display (LCD) screen." I have to make this distinction because, with the new Sony DSLT cameras like the A77, you're using live view whether you're looking at the rear display screen or through the (electronic) viewfinder. So I'm asking, why don't photographers more often look at their camera's rear display screen to compose and focus their shots? Why do they insist on using the tiny little viewfinder instead?
A couple reasons come to mind quickly.
First, it is almost certainly true that there is a sort of stigma against live view. Amateurs stand up straight, hold the camera out at arm's length and look at the rear display. Pros crouch a bit, and look through the finder. Pros also use big cameras, use Gary Fong lightspheres on their flashes (even outdoors), and wear flack jackets.
On a more serious note, live view has some problems in very bright light outdoors. The sun or some other bright light may cause glare on the LCD. In this case, it is simply easier to see through a viewfinder, especially an old-fashioned optical viewfinder.
Habit might also be a factor. For about the first decade that I was taking photographs, I was usually looking down to compose and focus, because as a student in high school and college I learned about photography using twin-lens reflex cameras (specifically, Rolleiflex). But I bought my first SLR (a Ricoh, if memory serves) around the time my first daughter was born in 1980, and the SLR's through-the-lens, straight-on, eyeball-to-camera viewfinder was all I had until a little over a year ago. If you have always composed through the finder, well, that is what you are likely to do. Even if you're young, you'll develop a habit quickly one way or the other — a reflexive preference for the finder or the LCD.
I think that, for me at least, the big reason is that using the finder feels more "natural". This is what struck me when I moved from compact digital cameras to my first DSLR five or six years ago. Looking through a viewfinder, you have the feeling you are looking directly at the subject. (Of course, you aren't, really. You're looking through a sort of periscope. But it feels like you're looking right at the subject and that's what matters.) Or perhaps it's the feeling that, with the camera jammed up against your cheek, your head and the camera are locked in sync. If you need to aim the camera a little differently, it's easy to do while you look through the finder. On the other hand, when you compose on the display screen, you are looking at the display screen rather than the subject. You hold the camera out with your arms, at least a little way, and it's quite possible to look to the right while pointing the camera to the left. There's a disconnect between what you see and what the camera sees. It's a little like trying to draw a picture holding an artificial arm.
Now, why do amateurs feel so comfortable using the display screen to compose? I suppose it's because they don't know anything else. Point and shoot cameras generally don't have finders at all, or if they do, they are terrible. I think it might also be the case that, just as pros don't want to look like amateurs, amateurs don't want to look like pros. Seriously. I know some amateur photographers who think that holding the camera up to your face is pretentious. Or at any rate would be, if they did it.
On the other hand, serious shooters with DSLXes have been shooting through the finder because optical viewfinders have, until very recently, been so much better than live view on the rear display. Really good live view is pretty new on these cameras. Of course, you can learn to shoot with the display rather than the finder. As I just acknowledged, amateurs with point and shoot cameras do it all the time. But if you're used to the finder, using the rear display initially feels wrong, awkward. You have to work at it, to get comfortable with it. So it's habit, and the more natural feeling you experience looking and shooting through the finder.
I am speaking from experience. My Nikon film and Pentax digital SLRs had excellent optical viewfinders and no live view. (The Pentax K20D had it nominally but it was too slow to be very useful.) When I converted to Sony I started with the A550 and A580. These cameras — especially the A580 — have lousy finders but excellent live view. Excellent live view on the rear display screen was still a novelty at the time (late 2010) and I was skeptical at first and used it only grudgingly. But over time, I realized I was getting better results looking at the rear display than I got looking through the finder. I also learned to like the features the rear display made available: focus magnification, a level, a live histogram, etc., not to mention the ability to pull the LCD screen out and tilt it or swivel it. All of this turned out to be good preparation for the A77.
I've been working this way for over a year now. I will confess that I do still feel slightly embarrassed about it. I worry that I look amateurish; don't want my portrait clients to think that. But they know better or they wouldn't have hired me. And I have for a long time peeked over the finder while shooting, to try to get a child's attention or see something better. And when I shoot on a tripod, well, live view on the LCD is a godsend.
I hasten to add, I continue to use the finder, as well, when I want to. With the A580, I have to flip a hardware switch on top of the camera to change between rear-screen live view and the (optical) viewfinder. This discourages me from switching modes as often as I might. The A77 has made this much easier, because it senses when I put my eye to the viewfinder and turns the EVF on automatically.
Remember that for a very long time pro photographers used big cameras and composed on glass screens in which the image was upside down and backwards. And they took some great photographs! I have heard it argued that the reversal of the image on the camera's viewing glass actually forced photographers to think more carefully about composition, and I can believe it. I am happy to be able to see things right-side up on my camera's rear display, but I think I compose a little more carefully on the rear display than I do through the finder.
I have given serious thought to bringing a big black cloth with me when I work outside on a tripod. I have thought about it because it would be useful. But it might look very professional. Or it might just look crazy.