Question about Focus Lock on D90

[luvpugs]

Happy Friday everyone! I've been playing around with my D90 and have a question about the focus lock (AF Selector Lock to "L") versus moving my focus points manually. Can I lock my focus point to the center, press the shutter half way down to focus and then move my subject within the frame to use the Rule of Thirds? I don't like how long it takes me to manually change my focus point to focus on my subject for every picture. If I'm in a hurry, can I just lock my focus point to the center, re-align my subject in the frame and then shoot the picture and it still be in focus? I was playing around with it last night and it looks like my subject will stay in focus, as long as I don't release the shutter button but I just wanted to check with those that are much more experienced at this then I am. I hope I'm making sense here! Thanks in advance for any feedback.

[zona5101]

It depends on what focus mode you are in but in Single Servo AF, pressing the shutter 1/2 way down will lock the focus and you can recompose. You can also use the AE-L/AF-L button if you have it programed to focus lock or have it in exposeure/focus lock (the default is both).