BBF, tracking and Servo on mirrorless cameras?

[stevet1]

I don't own a mirrorless, so I don't really know. I was just curious.

On mirrorless cameras, if you have BBF and tracking set up, and you are in Servo mode, do you have to keep the AF button, or whatever button you have assigned for BBF) continuously pressed in order to keep your moving subject in focus?.

Or do you even need to be in Servo?

Steve Thomas

[Waddizzle]

Yes.  If you do not press your BBF button the AF system shuts down.

Personally, I find pressing the two buttons simultaneously to be a little awkward.  I use the rear button for AF-OFF.  Now I have a better grip on the camera body and heavier lenses.  I can also get off a shot a lot faster when I need.  It is faster to press one button, instead of one button followed by a second button press.

[Tronhard]

If you watch the following video, it will explain how it works and how to set it up - BBF is not limited to mirrorless cameras, it can be done to almost all modern DSLRs and even some P&S ones as well.
https://www.youtube.com/watch?v=2AXUzslHnRc&t=2s

Also, this assumes you are using centre focus - I use spot centre focus to be very precise to get the eyes of my subjects or when they are very obscured within clutter.

Another advantage for me is that I can separate the focusing point from the exposure point - I also use single point centre exposure to be very precise on finding the 18% reflectance that the sensor is looking for.
So, in order this is what I do:
1  Centre the viewfinder on the point of metering and Tap the * button, to which I have assigned exposure lock
2. Centre on the point of focus and tap (for still) or HOLD (for tracking) to lock focus on the  subject
3. Recompose and shoot

I totally respect that Bill does not like it - and it's absolutely a matter of teste, but for me and many others it's a fabulous feature - note: you need to have servo turned on for this.   I use it all the time, but if you try it you need to give it some time to become embedded in your proprioceptive memory.

[stevet1]

Trevor,

I use the same method myself.

I guess I was asking about the relationship between Tracking and Servo and following subject movement. I don't use Tracking myself, but I get the feeling that it's a big part of the mirrorless milieu. I hardly do any photography where movement is involved. It's all static, still stuff.

Mirrorless milieu. Static, still stuff. I guess I'm into alliteration today.

Steve Thomas

[Tronhard]

Ah, sorry Steve, I didn't get that.   I have a hybrid set up with face and eye tracking set up so that if it does not find the target I want, I can correct it by placing it in the centre of the viewfinder and pressing AF-On to give it a hint.  Often thereafter it gets the message and tracks.

Funnily enough, I do much the same as you these days - I am doing more animal portraits than birds on the wing or other creatures running around - given we have birds here and not much else except sheep and cows (wonderful creatures, but...) I have to take what I can get! 😊

[p4pictures]

I've reached a view that back button AF is one of those polarising topics, akin to Windows vs Mac.

Myself I used BBF for many years on my EOS 5D Mark III / 5D Mark IV and EOS 7D Mark II cameras, even a EOS Rebel SL2 / 200D. My use of BBF was kind of a way to eliminate the need to switch to one shot AF, and simply leave the camera in servo AF all the time. With a back button I would press and hold the button for servo AF, tacking the subject. By pressing the button and then releasing the camera would have focused and since I released the button the focus stays where it was, kind of like one-shot AF. Most DSLRs have better AF points at the centre of the frame, this makes it better to use central points with this setup.

Moving to mirrorless with the EOS R I found the AF-ON button to be badly placed and the slope of the button meant I had little feel if it was pressed or not. So I stopped using BBF on that camera. I also found that for people, I could use subject and eye tracking with servo. The camera located the face and eye in the frame and focused on it, even if the subject or me moved. The result was more sharper shots.

When EOS R5/R6 arrived I initially tried back button AF and it was much better in terms of button placement and feel, but what I also found was that subject tracking meant I could aim the camera at the subject and it would find the face / eye and focus on it even if it moved around the frame. So the need to lift off the back button to achieve focus lock and then let me recompose the frame was gone. Once the subject was found I just recomposed keeping the button pressed. Then I realised I didn't need to use BBF anymore and haven't since. 

I have found that my mirrorless camera are set to servo AF all the time, and I'm more likely to use manual focus than one-shot for static subjects.

What I have done is experiment with what else to do with the AF-ON button, and I've used it as AF-OFF to stop focus - a bit like lifting off the button in the past - and now I mostly use it to recall an alternate camera settings as a way to change my shutter speed when shooting sports. 

I am amazed that some people use double and triple back button setups with the AF-ON, asterisk and AF point button all instigating different AF settings and focus. My own brain and manual dexterity does not cope with this. Though I often change my camera setup specifically for the subject I am shooting.

[Tronhard]

I too am somewhat amazed at multiple versions of BBF.  I still prefer the 'old' style as in the videos from Canon that I post up for those who want to consider or use it.

Whether one does or does not, or how one does, I think that the great thing is we all have multiple options to choose from, and that has to be good:  cameras have come a long way in ergonomics, and control over controls.

[stevet1]

" double and triple back button setups with the AF-ON"

" multiple versions of BBF"

I can see that my initial confusion was not unwarranted.

Steve Thomas