Using live view drains batteries, fast. So why do I use it?
Getting sharp images is my main reason, that and poor eyesight.
I say at this point that I rarely use auto-focus, I prefer to set my own focal point and look at the image overall. I never found live view particularly helpful when using auto-focus as the camera and lens do all the work, you just need to set the exposure and depth and voila.
Anyway, back to live view: looking through the viewfinder is in many ways like seeing the image directly, as though with the naked eye. You don't get a feel for the brightness or depth of the image you are going to take and most importantly where focus is concerned: you cannot 'zoom' in to check your focus etc.
With live view, the image you are about to take will appear on the back of your camera, just like on your phone.
If you change the exposure or depth of field you can see those changes on the screen. This is really useful in helping determine what the overall image will feel like and how much of it is in focus.
But, the thing I use it for most is to get that pinpoint sharpness where I most need it. Before I discovered this live view trick my images were never quite as sharp.
This image was one of my earliest photos and as you can see its a bit sloppy on the focus.
To do this, I click on the live view, close down the shutter so that its on the lowest aperture possible, for most of my lenses that's f1.8.
Once there I zoom in to the spot I want to focus on (on the display not the lens if you happen to have a zoom lens attached), this might be an eye, the edge of a leaf, a particular flower ...
Now, I get on that focus ring and get that spot into absolute clarity. With my Nikon that can be a bit tricky as the image resolution on the screen quickly becomes fuzzy, but I got the hang of it eventually.
When I'm happy that spot is in focus I go back to full view on the display. At this point, other than that one spot, most of the image likely looks out of focus. I then get back to the aperture and roll it back out again. I usually set it to the sweet spot for the lens if I can get away with it, usually around f5-ish depending on the lens and how far away I am from the object, so I can get some nice sharp edges. But for my landscapes I'll be rocking it up to f8 or f9 regularly to get a nice overall focus without getting too soft.
And yes, I always take a spare battery!
Michelle
This image is much sharper (except the bee was moving around too much), and I chose to keep the focal range low so that the background was nicely blurred.