20D focus points

Bob, this is starting to get very surprising to me - partly because it conflicts with every piece of documentation I've read, and partly because I can't get my camera to behave the way you're saying. You're literally claiming that focus lock (half press) doesn't actually lock focus when in multi-point AF mode. You're saying there will be another focusing action when the shutter button is fully pressed. That would also necessarily introduce a huge amount of shutter lag.

Are you REALLY sure your camera does that? Can anybody else replicate this result?

Those were not the words that I used.

---Bob Gross---

I think that one of the distinctions here is whether you go from the half-press stage to the full press stage _directly_ or not.

One scenario is to half-press the button, get the candidates, and then continue pressing down on the button without lifting up. At the half-press stage, the candidate is active and is held active all the way down on the button.

Instead, if you half-press and then lift up, and then full press the button, it will go back through the autofocus selection cycle again, and that is what adds a little lag.

I think it is because of the complexity of the multipoint selection why most of us shoot using the center point most of the time.

---Bob Gross---

Wow, a very interesting thread. I don't know much about this stuff, but what I do is I focus auto and then while keeping the button half pressed I focus manually and allways get good results.

Regards,