An alternate to BBF

[Only RF]

Just to add many years ago pro photographers asked Canon for this feature. Not everyone finds it easy to keep the shutter ½ passed, especially between burst sequences while tracking a moving subject. When this feature was added AF was no where as sophisticated as it is today. If you lifted your finger off the shutter past half way AF would stop and it could be difficult to reacquire it again.

Removing AF from the shutter and assigning it to the AF-ON solved that problem. You could press and hold the AF-ON and AF is was engaged continually. The shutter was in charge of metering and of course exposure. If you lifted your finger off the shutter past ½ way AF is not interrupted.

Todays AF is so much more advanced. The most basic cameras are better than the high end ones from when that feature was added. Lighting quick AF acquisition, very good tracking not to mention eye AF.

As Bryan said these days there are so many more customizing options available with mirrorless cameras. When the AF-ON feature was first released that was it. AF-ON just activated AF. Maybe the D line had an option or two but no where near what even the R10 has today.

One day while trying to find better ways to control eye AF I asked myself, do I really need to remove AF off the shutter with mirrorless AF tech? By not doing so freed up another BBF to better control it. It may not work for others but I've really been enjoying shooting that way.

 

[Philnick]

The reason Back Button Focus was invented was so that pressing the shutter would not refocus after you had already focused where you wanted to. That concern is as valid now as ever. You've focused on something the camera might not select on its own. Do you want to let it second-guess you and focus somewhere else just as you press the shutter button?

I've recently switched from Servo AF to Single Shot on my R7 so it doesn't continually freelance and change where it's focusing. This way, it will continually focus Servo-style as long as I hold in the AF On button, but when I let go of that button focus will stay where it was.

What motivated the pros' request to Canon long ago was the need to prevent their focus on their chosen subject from being stolen away by someone or something else nearer as they pressed the shutter. That hasn't changed.

Automation is fine as long as we can choose when it operates but not when it decides to be a back-seat driver and grab the wheel uninvited.

For the same reason, I don't use autoexposure, just Manual exposure with a live histogram in the viewfinder. I don't want my exposure to continually change as I pan around a scene. I grew up with a match-needle exposure gauge in the viewfinder of my film SLR. I want to be the driver, not a passenger.

 

[Only RF]

I've been shooting with the shutter half pressed and or the AF-ON for AF and don't recall my cameras ever refocusing on anything else. I always have RS set to -2 so if something temporarily interferes with the subject it ignores it. It's a little different these days with eye detect because if another person obstructs my original subject it is obstruction with an eye. STS takes over.

This is the reason I used BBF before I started using it for an eye detect override. I can do this just as easily with the shutter ½ pressed. This frees up another BBF for overriding eye detect

Similar to point number one above, but yet another benefit of pulling focus away from the shutter button is that critical timing becomes simpler to manage. For example, if you were shooting a speaker at a podium, he or she might periodically look up or make a gesture that would be an ideal instant to capture. If you’ve focused with back-button AF, your index finger is free to shoot at the decisive moment. There are no worries about holding your finger half-way down and waiting, waiting, waiting in that position for your subject to do something interesting.

https://support.usa.canon.com/kb/index?page=content&id=ART170279

 

[Only RF]

Just so I'm clear when use the shutter ½ pressed I track a bird and do series of burst shots. Between burst shots I find it easy to raise the shutter button back up to half way and not further so as to not lose AF. These if I do AF Preview kicks in. In a crowd I disable AF Preview if I want to track one subject.

 

[Philnick]

Found last night that eye detect wouldn't work at all in Single Shot mode and I had to put my R7 back into AI Servo mode for it to find anyone's eye.

Am I missing something?

 

[Only RF]

It should. Did you that by changing a mode like C1-3? I’ll test it and get back to you.

 

[Philnick]

No. I run with the mode dial set to M.

 

[Only RF]

I use M mode and C1-3 are also M. I have custom options for each mode. I was not sure so that was why I asked. You are sure you in Eye Detect?

 

[David Berry]

I use M mode and C1-C3 are also M. I have custom options for each mode.

That’s also my choice for my R5.

 

[Only RF]

Up in Canada and our football Western final is on. I’ll test at ½ time.