Back Button Focus...

bildeb0rg wrote in post #18903201
If someone can tell how to set up camera so it knows which player I want to shoot on a rugby/soccer pitch (the one I've been tracking and not the one that's just crossed in front of him) please let me know. I have to split focus from shutter button to do this, so I'm BBF I'm afraid.

The DWIM button (Do What I Mean)...Can't find it?!

Wilt wrote in post #18903443
The DWIM button (Do What I Mean)...Can't find it?!

Wilt, that will be on the 90D that everyone is waiting for.

I switched to BBF early on in the hobby. I started doing it at first because it is so much easier to focus and recompose. Plus it's easier when I wait for a bird to take flight. A Heron e.g. has the bad habit of leaving all of a sudden. Often they will relieve themselves first, but not always and also if they do poop, they may decide to stay a bit longer after all. Having to keep the shutter button half depressed all the while is uncomfortable. I can do it a few minutes, but half an hour or longer, waiting? And then what? I get the first shot but the camera will continue to focus with every new shot. I might not want that, e.g. if the bird is flying parallel to the sensor.

I also shoot swallows in flight and sometimes there is no other way to shoot them than to pre-focus and start shooting bursts as they come into the zone. AF of course needs to be away from the shutter button for this. Here is an example of a situation where AF will most always fail: Swallows or in this case, House Martins flying to and from the nest. They enter the scene suddenly and leave with an abruptness that makes you scratch your head thinking "was that a bird?"

It's a composite of the flight path of three or so birds circling the nest. I make one or two of these kinds of composites every year, just for my own books; it's not really fit to be put on display but it is one reason for BBF.

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Gregsiem wrote in post #18903447
Wilt, that will be on the 90D that everyone is waiting for.

I'm gonna sell my 7DII to get that button!

I think to prefocus and take a shot when there is activity, not using BBF, you would have your AF ON be set to AF OFF. You would half press the shutter to pre-focus, let go, then when you want to take a shot, you hit AF OFF (AF ON) and then press the shutter.

You have to think negatively about things this way, instead of "I want focus, so I hold focus down" and "I don't want focus, so I don't touch the focus button" versus
"I want focus, so I hold down the shutter half-way" and "I don't want focus, so I have to hit another button to turn off focus, then press the shutter button".

Assuming I understand the usage of the "AF OFF" setting you can customize to a button. If I do, and I am correct, it is harder for me to think about combinations of buttons I have to press to do things and also to not do things, versus the buttons all doing something if I press them and if I don't want them doing anything, I don't press them.

TeamSpeed wrote in post #18903458
I think to prefocus and take a shot when there is activity, not using BBF, you would have your AF ON be set to AF OFF. You would half press the shutter to pre-focus, let go, then when you want to take a shot, you hit AF OFF (AF ON) and then press the shutter.

You have to think negatively about things this way, instead of "I want focus, so I hold focus down" and "I don't want focus, so I don't touch the focus button" versus
"I want focus, so I hold down the shutter half-way" and "I don't want focus, so I have to hit another button to turn off focus, then press the shutter button".

Assuming I understand the usage of the "AF OFF" setting you can customize to a button.

Sounds like using Reverse Polish Notation for maths...I could never quite get my head around that either

BBF was a chore for me at first, now I'd hate to have to go back. It's the perfect solution for focus/recompose (IMO). I've found it especially helping with sports and AL SERVO. It would just seem to me that only asking the shutter button to release the shutter might speed things up just a tad??? Not having to constantly focus on something, especially something that hasn't moved at all, is just so much easier for me. I use to always accidently fire the shutter when I didn't want to while trying to maintain focus, now it never happens. I just noticed the other day at a press conference. My subject was sitting at a microphone, so focus would not change. You are just waiting for the perfect facial expression or a laugh/smile, and sometimes waiting 20, 30, or more seconds between shots. Why would I want to sit there holding the focus button down getting a cramp in my old finger I would think you'd have 3 options in this situation: 1) Focus, then turn AF off on the lens. 2) Constantly holding the button down waiting for the right moment to release. 3) BBF. #3 is the only option for me.

I honestly cannot think of any other situation where a button has a halfpress and a fullpress setting where the halfpress does something completely different than the fullpress, but to add insult to injury, when you do a fullpress, the halfpress action still executes, sometimes just for a bit, sometimes full-time depending on your settings for the halfpress action, and to prevent the halfpress action from occurring, you had to hold another button.

Even when you google half press button, you get almost exclusively camera related topics.

I am sure there is an application out there that has this, but I cannot think of one. I went through automotive, kitchen, misc home, even laptops/keyboards/tabl​ets/phones and home defense products. If there was something in the automotive world, it would be Tesla, or Audi or BMW. Perhaps the control knob/touch pad on the luxury cars?

This is probably why BBF is so popular, it seems more logical to have two state dedicated buttons to do independent things, it is how most things are operated in our lives. The psychology behind this topic is quite interesting actually.

The slider bar on the R serves 3 purposes, and could be 3 different unrelated things too, but still isn't the same. You don't have to go through one action to get to the other action.

This press conference lasted 12 minutes. I focused once.

Pigpen101 wrote in post #18903529
This press conference lasted 12 minutes. I focused once.

Um, okay.

I guess I just don't see that as being an environment where focusing would be a chore...

Pigpen101 wrote in post #18903529
This press conference lasted 12 minutes. I focused once.

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... and ... Seems like once should be plenty for a subject that is not moving. Not sure what you are trying to say. I can focus only once (using BBAF) on an 8-second, 50 yard football play, and get both ends of it in focus.

It's not....if you use BBF. Holding the shutter button half way for long periods of time can be a pain. If your camera allows you the opportunity to make life easier, why not use it.

???????? Not sure what you're trying to say. Focusing once IS plenty. So why hold down the shutter button half way for 12 minutes!!!

I offered 3 ways to focus on this subject, which would you 2 guys use??

I think the point that could have been made there is that with BBF, you would focus just once, and then as the player answered questions around the room looking in one direction then another, all you have to do is recompose and snap pictures.

I probably have something inaccurate here, and fully expect to be called out if so, but here we go...

If you had focus on the shutter button and wanted to recompose each shot, you would have:

a) go to One Shot
b) put the AF point on the player, half-press, wait for the AF to lock, then recompose and take a shot, rinse and repeat

or (less tedious but still a bit annoying)

a) focus on the player once by half pressing, then let go
b) each time you want to take a shot, hit the AF-OFF button first, then compose and hit the shutter

or (even less tedious, but a bit more annoying)

a) focus on the player once by half pressing and letting go
b) turn AF off on the lens
c) proceed to compose as desired through the interview and take shots

With BBF,

a) Use AI Servo or One Shot, doesn't matter
b) Use the back button to lock focus
c) proceed to compose as desired through the interview and take shots
d) If you ever want to refocus, just go back to b)