Focus with Shutter or * [AF ON] button? -READ ME-

DDan wrote in post #4267217
I prefer the default setting for C.Fn. 4 when shooting action. I do motorsports so I always shoot outside in predictable light.The camera continuously focuses while you are holding the shutter button when you are in AI Servo.

The camera sets exposure at full press of the shutter button and then locks again prior to each shutter actuation when in Continuous drive mode. When in M mode, the exposure doesn't matter anyway.

Adding another button doesn't buy me anything that I can think of.

You arn't swinging around to track the subjects?

I prefer 4-3 for motorsports as I am tracking cars/bikes/karts and want the camera to expose for each shot.
If I'm shooting anything where I want the exposure to lock I go for 4-1.

DDan wrote in post #4267217
...Adding another button doesn't buy me anything that I can think of.

Using C.Fn-04 (1 or 3) with AF on the lens turned on and with the camera focus mode set to AI Servo...

A.) Holding down the * gives me AI Servo focus.
B.) Pressing and releasing the * gives me 1 shot focus.
C.) Not pressing the * at all gives me manual focus.

ALL without changing a single setting on the camera or lens!

These are just some of the advantages you get with C.Fn-04.

I tried to force myself to do it. My brain just couldn't handle it. It was kind of like how I know I'll never be able to play the piano with both hands.

I'm understanding the benefits, but run into too many drawbacks and have to switch back and forth. My indoor night work often needs the AF assist beam on my 580EXII, so I have to go back to One Shot focus for that. Plus, I'm occasionally in situations where others might need to grab my camera to take a picture of me...they're going to miss the shot otherwise.

Phil Light wrote in post #4268917
Using C.Fn-04 (1 or 3) with AF on the lens turned on and with the camera focus mode set to AI Servo...

A.) Holding down the * gives me AI Servo focus.
B.) Pressing and releasing the * gives me 1 shot focus.
C.) Not pressing the * at all gives me manual focus.

ALL without changing a single setting on the camera or lens!

These are just some of the advantages you get with C.Fn-04.

Good in theory, but if you need focus tracking for long periods then there are better solutions.

cwphoto wrote in post #4269133
Good in theory, but if you need focus tracking for long periods then there are better solutions.

Could you please elaborate; what situations do you have in mind and what are the better solutions?

FretNoMore wrote in post #4269313
Could you please elaborate; what situations do you have in mind and what are the better solutions?

Field sports for me. When the bulk of my shooting is following moving targets I set to C Fn IV-1 to 1.

This allows AI Servo focus tracking with the shutter release button only, while the AF-On button becomes an AF-Off button for those times when MF or One Shot is desirable (team huddles, statics, shots on goal etc).

I fail to see the value in removing AF from the shutter button under such circumstances.

In a way I agree, it's also more useful to separate focusing and exposure lock for static targets where you might want to, and have the time to, meter off one spot and focus on another. Still, personally I am more comfortable to always have the camera set up the same way, I think I would miss shots if I have to think of which configuration the camera currently is in.

FretNoMore wrote in post #4269550
In a way I agree, it's also more useful to separate focusing and exposure lock for static targets where you might want to, and have the time to, meter off one spot and focus on another. Still, personally I am more comfortable to always have the camera set up the same way, I think I would miss shots if I have to think of which configuration the camera currently is in.

Same here, which is why I could never get used to AF and shutter release on separate buttons - so I just leave AF to the shutter button and "freeze" AF via the AF-On button.

As for mettering, I'm often in M mode so it's largely irrelevant to me.

It's great to have the choice though.

I have played with putting the AF on the * button, and I sort of like it sometimes. I think the idea of having the exposure and AF split up on different buttons makes alot of sense. That said, I think the biggest problem is the placement of the * button itself (at least on the XTi). If the button were where the thumb rest is currently, it would feel much more natural. It just feels a bit too cramped. It might be okay on the bigger cameras, but it is quite uncomfortable on the XTi.

pjtemplin wrote in post #4268939
I'm occasionally in situations where others might need to grab my camera to take a picture of me...they're going to miss the shot otherwise.

Easiest thing to do when handing the camera over to someone else is to put it into idiot mode : green square.

Easier said than done: no such animal on the 1D Mark III.

I taught my wife to put it in green box when she needs it, and she was quite upset when she missed about 5 shots in a row. I forgot to mention to her that she needed to make sure the lens was set to AF.

Phil Light wrote in post #4268917
Using C.Fn-04 (1 or 3) with AF on the lens turned on and with the camera focus mode set to AI Servo...

A.) Holding down the * gives me AI Servo focus.
B.) Pressing and releasing the * gives me 1 shot focus.
C.) Not pressing the * at all gives me manual focus.

ALL without changing a single setting on the camera or lens!

These are just some of the advantages you get with C.Fn-04.

I don't use 1 shot or manual focus for motorsports so C.Fn-4 set to 1 or 3 just means I have to push 2 buttons instead of 1.

I think it’s important to note; I’m not trying to change anyone’s mind or state that C.Fn04 is the best solution for every situation. I’m just beginning to realize that for me, it provides the best of all worlds. I don’t shoot just one type of shot all the time, therefore having that kind of versatility is very helpful.

But most importantly, there is no right or wrong way to do it. It’s just personal preference.