Hurray for live view
That is why I switch live view off once I am set up and snap the picture at the right moment (instantly) with my remote in normal mode (usually A mode).
I'm new with live view, so maybe someone has a better way. That lag in live view is rough on a breezy day when we are talking less than a second of calm as the breeze subsides. It also saves batteries to use it sparingly.
Another thing I learned is the D5100 has no preview mode, but you can get a image preview in live view and if you change the aperture, just turn off live view and when it is turned on again it will show the new aperture at the correct depth of field like my D80 preview button did. At least I think it does- bper