Back button auto focus

[mentosik83]

I can't find it anywhere so please forgive me if this is something obvious.
I have sony a6400 in seaftogs salted line housing and it is annoying to turn on auto focus by a shutter trigger. I wanted to install a trigger to the rig but it looks like there is nothing on the market.

I understand people use back button for focusing but I don't understand how does it help since you have to press the button all the time to focus and then, using another finger to press the trigger. I find it super uncomfortable since I don't have much clearance between rig handle and shutter trigger.

Is there an option to configure the camera to turn on auto focus by a button and it will track what I selected by a button in a toggle type of operation? Meaning I want to press a button to turn on autofocus but when I release that button I want the auto focus still tracking what I selected. Can't find it in my camera not the Internet :/

Please advise.

 

[gstrek]

I can't find it anywhere so please forgive me if this is something obvious.
I have sony a6400 in seaftogs salted line housing and it is annoying to turn on auto focus by a shutter trigger. I wanted to install a trigger to the rig but it looks like there is nothing on the market.

I understand people use back button for focusing but I don't understand how does it help since you have to press the button all the time to focus and then, using another finger to press the trigger. I find it super uncomfortable since I don't have much clearance between rig handle and shutter trigger.

Is there an option to configure the camera to turn on auto focus by a button and it will track what I selected by a button in a toggle type of operation? Meaning I want to press a button to turn on autofocus but when I release that button I want the auto focus still tracking what I selected. Can't find it in my camera not the Internet :/

Please advise.

I have a Sony A6000 in the SeaFrogs Salted Line housing and use C1 for BBF. This lets me use my index finger on C1 to focus and middle finger on the shutter button. It is more comfortable and 'natural' feeling than I thought it would be. This allows autofocus as long as the C1 button is pressed.

I don't know of any way to configure it as a 'toggle type of operation' and not sure I would want that as it would use a lot more battery if you left it that way for too long (forgot to toggle it off).

 

[BoltSnap]

I have a Sony A6000 in the SeaFrogs Salted Line housing and use C1 for BBF. This lets me use my index finger on C1 to focus and middle finger on the shutter button. It is more comfortable and 'natural' feeling than I thought it would be. This allows autofocus as long as the C1 button is pressed.

Does this "Back Button auto focus" feature allow for refocusing as the subject moves or changes distance or does one have to release the button and press it again to refocus?

 

[VsubT]

If tracking autofocus mode is used, the camera should keep the subject in focus while the custom button assigned to focus is depressed.

I’m not aware of any way to do “toggled” BBF on Sony a6xxx cameras.

Lance

 

[gstrek]

Does this "Back Button auto focus" feature allow for refocusing as the subject moves or changes distance or does one have to release the button and press it again to refocus?

It depends. On AF-S you have to release the button and press it again to refocus. On AF-C, it is continuous autofocus. I use AF-S (works better for me with an older model a6000). Once I have my focus, I can release the button and it will hold the focus if I need to recompose. AF-C would be a better choice but I have a hard time getting focus in an underwater environment.

 

[mentosik83]

This allows autofocus as long as the C1 button is pressed.

that's the point, I don't want that. I want to be sure when I press the shutter my object is in focus. When I depress the button and move my finger to shutter the focus may change.

If tracking autofocus mode is used, the camera should keep the subject in focus while the custom button assigned to focus is depressed.

Well, it doesn't work that way for me. I have AF-C, tracking center, custom button set to AF-ON and the camera focusing only when the button is pressed.

 

[VsubT]

Well, it doesn't work that way for me. I have AF-C, tracking center, custom button set to AF-ON and the camera focusing only when the button is pressed.

Pretty sure we’re saying the same thing. Good luck with your photography adventures.

Lance

 

[mentosik83]

Sorry Lance, you are right. I misunderstood you.

 

[Nemrod]

Does this "Back Button auto focus" feature allow for refocusing as the subject moves or changes distance or does one have to release the button and press it again to refocus?

Back button focus is a game changer. It allows me to set my focus in advance and decouples focus from the shutter which stops autofocus hunt. Be it wide angle or macro or inbetween being able to set focus and have instant shutter response is huge, no focus lag. I would not buy any camera or housing without BBF capability.

I toggle the BBF control on my NA6400 which is just like the shutter but behind it with my thumb and shutter is on my forefinger control. Very easy and intuitive, no difficult half press and tenuous hold needed. The Nauticam uses two levers, thumb for BBF and fore finger for shutter.

It is easy to revert to coupled shutter and focus for whatever reason it might be preferred, hard to imagine. I often preset focus for quick snap action shots or for macro preset focus and move the camera back and forth until in focus.

I usually use center weighted or spot metering, metering is still on the shutter lever of course. I also set single focus, not continuous, and center focus so I know what exactly is going to be in focus, swing the camera to subject, position and fire away. I would not want a button, I want it to be a lever like the Nauticam. Which engages a button on the camera to which I assigned the BBF control to.

To be clear, I do not have to hold the BBF lever in single frame focus mode. I toggle the BBF, focus is set immediantly to whatever I center in my frame. If I want to change focus distance then I must toggle the BBF control again with my new subject in the center. I can recompose without holding the BBF control, focus is fixed until I toggle the control again.