Back Button Focusing Confusion: My understanding that when using BBF, that you view your target thru the viewfinder, hit the BBF button and release, recompose if you want, then press...

47greyfox Loc: on the edge of the Colorado front range

My understanding that when using BBF, that you view your target thru the viewfinder, hit the BBF button and release, recompose if you want, then press the shutter button. Sound right, so far? I thought that was regardless of whether you're shooting "One Shot" or "AI Servo," then I read a thread posting here on UHH a couple days ago. It suggested that when shooting "AI Servo" that you hold the BBF button down while following the subject. That makes sense since the subject is moving. If that's true, do you then release the button before pressing the shutter?

An enquiring mind (mine) needs to now since I've only had less that stellar success with BBF and figure (besides practice), there has to be a reason. And setup isn't it.

riderxlx Loc: DFW area Texas

47greyfox wrote:

My understanding that when using BBF, that you vie... (show quote)

Good question,
I too am curious, will be following this.
Thanks for posting,
bruce

rwilson1942 Loc: Houston, TX

With moving subjects, I keep the BB pressed while shooting.
Others my differ.

johngault007 Loc: Florida Panhandle

If you want the camera to keep adjusting focus, hold whichever button you are using for BBF the entire time. It's like have AF One Shot (compose and release) and Servo (hold down) in one button.

47greyfox Loc: on the edge of the Colorado front range

rwilson1942 wrote:

With moving subjects, I keep the BB pressed while shooting.
Others my differ.

But.... do you release just before depressing the shutter or keep the BBF button pressed?

johngault007 Loc: Florida Panhandle

47greyfox wrote:

But.... do you release just before depressing the shutter or keep the BBF button pressed?

He keeps it pressed. That's what I do as well.

kpmac Loc: Ragley, La

I keep it pressed if the subject is still moving.

lamiaceae Loc: San Luis Obispo County, CA

47greyfox wrote:

My understanding that when using BBF, that you vie... (show quote)

What brand, what model camera, what model lens? I see "AI" so are you using a Nikon?

Personally, since I don't really shoot moving birds or people, I don't mess with the BBF set up at all. I've tried it and it confuses me. Too many years shooting film manually I guess.

johngault007 Loc: Florida Panhandle

lamiaceae wrote:

What brand, what model camera, what model lens? I see "AI" so are you using a Nikon?

Personally, since I don't really shoot moving birds or people, I don't mess with the BBF set up at all. I've tried it and it confuses me. Too many years shooting film manually I guess.

Canon cameras.

I stick to mostly landscape and things that aren't living. So using BBF is great when I do need to switch to moving objects, or just walking around, I'll focus where I want using the back button, then compose. It's not for everyone, but once you get the hang of it, and it's on a comfortable button to use, it becomes pretty easy to use.

philo Loc: philo, ca

if you don't erase the focus from the sutter button it will refocus and you lose the bbf.

lesdmd Loc: Middleton Wi via N.Y.C. & Cleveland

I think an example will provide clarity. Shooting soccer game. (Camera is set in continuous shooting mode): focus on subject and keep BB button depressed while following player(s) of primary interest and depressing shutter button. Invariably, someone will enter the field of vision and the camera will likely try to focus on new player causing your primary subject to go out of focus. If you are quick enough, release BB and focus will remain locked on original subject rather than focusing on new player entering subject. In the real world, the game moves so quickly anticipating when focus might change is impossible. Main advantage of BB is that you can, with a bit of luck, follow action; and then switch to sideline and, with one push of button, lock focus on players on the bench.

johngault007 Loc: Florida Panhandle

philo wrote:

if you don't erase the focus from the sutter button it will refocus and you lose the bbf.

Yes, if set up correctly, that is the intended purpose.

Bullfrog Bill Loc: CT

rwilson1942 wrote:

With moving subjects, I keep the BB pressed while shooting.
Others my differ.

Nope, that is correct. But yo8 should always be in AI Servo. You can also release the BB and recompose just like you were in single servo.

Anhanga Brasil Loc: Cabo Frio - Brazil

kpmac wrote:

I keep it pressed if the subject is still moving.

I do too.

47greyfox Loc: on the edge of the Colorado front range

lamiaceae wrote:

What brand, what model camera, what model lens? I see "AI" so are you using a Nikon?

Personally, since I don't really shoot moving birds or people, I don't mess with the BBF set up at all. I've tried it and it confuses me. Too many years shooting film manually I guess.

Canon 6d2 and 7d2