Okay, had to go away for a bit and thought a lot about this while driving
So this is what I came up with (I may be way off....someone set me straight if so)
this winter we had a rockin awesome blue sky. I was taking pictures of a chicadee in a tree but really wanted the sky to be what was exposed correctly, so in that case I metered off the sky, and I locked the exposure (using the button on the back of my camera that locks it...Not with the method I originally posted about, where it is locked along with focus with my shutter release button) then recomposed, focused on the bird and I really got (what I think) is an awesome shot, with a really beautiful sky. In that case, having the focus AND the exposure both set to lock when I push the shutter half down, would not have let me meter off the sky and then recompose and focus on the bird, it would have metered off and exposed for the bird, and I may not have gotten that awesome sky that I got in the shot. So if I were to take pictures of only chicadees, I would be better off UNlocking the focus and exposure so they are not both on the same button and just using the button on the back of the camera that locks exposure. Does that sound right?
But, when doing portraits, it really doesnt' matter as much since really you want to expose for the skin (MOSt times) and you usually focus on their eyes anyway, so really when you recompose, you don't really change the lighting you are exposing off of anyway, so really even using the exposure lock button that just locks exposure from one frame to the next is really a waste of time. I wonder if that's the same when shooting a group of people though?
Quote: Do you know why they are OOF? A lot of reasons can contribute to it and your solution only protects against one, which is an object moving during your recomposing stage.
when thinking about this, as I stated before, I don't get an abnormally amount of photos where I miss focus, BUT....I think when I do, it's because of the subject moving slightly. For examply, I recently shot a Senior and didn't get one single shot where focus fell somewhere other than where I wanted it too. I think with an older person it's because you say "Stay" and they stay. As opposed to 6 month old twins I recently shot where I had some images where the focus fell somewhere other than where it was supposed too. Must be because in the amount of time it took me to recompose, he/she moved (and they moved a LOT...trust me) So really, I'm not unhappy with my focus most times, so maybe I shoudl just leave well enough alone?
RioRico I do shoot RAW, and I am thankful for that "Wiggle room" you mentioned. It has saved me that's for sure. I just really love the thought of nailing it in camera and having NO post processing work to do (haha sounds great right!? don't we all wish for that) I guess my questions are just because I wanted to know, again, I'm not disapointed in results I"m getting, I just want to know if there is a better way. So, I always shoot in manual and adjust my settings according to light and movement of subject...all that good stuff. and I always have my camera set too spot metering and center focus. I wonder how much different center weighted metering is. I think I may have to take baby girl out and mess around with them both some.
I'm also still confused about the back button focus button that so many people rave about. I'm still not sold. Of course, I've never tried it. Maybe if I did, I'd rave too. Can anyone tell me why back button focus is better than just pushing the shutter button half way down? May have to try that out later too. I may be back to post my rave!!