boberic Loc: Quiet Corner, Connecticut. Ex long Islander

Definitely shut the half press off

monroephoto

The concept of BBF does apply to many serious cameras and brands. I notice you shoot Nikon and Sony. To activate back button focus, the cameras may have a different set up to separate the focus and exposure functions from the shutter button. But this set up is only a small part of understanding the utility and usefulness of a back button focus choice. WARNING: if back button focus is something you might want to try and activate on your cameras, you will likely need to initially read an instruction manual. That might consume minutes of your time, as opposed to the maybe ten seconds it took you to read two lines of text in that post.....which, by the way, seemed to be very helpful to the sender. Isn’t that what this forum is all about? Have a great day, sir.

amfoto1 Loc: San Jose, Calif. USA

For any moving subjects you MUST continue focusing.... so you cannot lift your finger off the AF On button (i.e., the "Back Button")...

But since you're using BBF you don't need to keep the shutter release button half-pressed. (Just be sure you have, in fact, set up BBF... which on those Canon models simply means turning off AF at the shutter release button, since by default the AF On button is already set up to start and run AF).

The reason for this is because the AF On button will continue to maintain focus (just be sure you've selected AI Servo).... AND because pressing the AF On button also activates the metering system and keeps image stabilization running.

HOWEVER, I would recommend you get in the habit of also maintaining half-press of the shutter release button (which also starts and runs metering and IS, even when BBF is set up). The reason is that lifting off the shutter release may lead to more camera shake. When you try to take a quick shot without your finger on the shutter release, the temptation is to "stab" at it.... which can cause camera shake (IS can't solve all camera movement issues). But if you maintain half-press on the shutter release button, you're more likely to use a more proper quick but gentle "pressing movement" to take the shot, as recommended for the steadiest shots possible. In my opinion, it's "good technique" to keep the shutter release half-pressed while tracking your subject.

Think of it as if you're pulling the trigger of a gun. While for safety reasons it's recommended to keep one's finger off the trigger until ready to shoot... Once the gun is aimed down-range we're ready, high precision target shooting has us put light pressure on the trigger and slowly increase pressure until the gun fires... rather than using a "jerking" method that's very likely to pull the gun off target. In fact, many precision shooting rifles now come with a two-stage trigger that acts a lot like the half-press shutter release buttons we've used for years on cameras.

With a camera, you don't have the risk of an accidental discharge like there is with a gun. I mean, what's the worst that can happen with a camera if you accidentally trip the shutter? Especially a digital that can fit hundreds or thousands of images onto a memory card. You just end up with a bad image to delete now or later in post-processing (you never know, though, so I generally don't delete in the field... well, except for those shots of my toes ).

Regarding a wired (or wireless, I suppose) remote... I'd mostly use one for stationary subjects. In those cases, it wouldn't matter whether BBF is set up or not. In some cases, a remote might be used to trigger a camera to capture a shot of a moving subject. But that would usually involve pre-focusing, in which case it also wouldn't matter if BBF is set up or not.

However, there also may be situations where you want to control AF remotely (regardless whether in AI Servo or One Shot mode)... in which case I'm pretty sure BBF would need to be temporarily disabled (i.e., shutter button half-press AF would need to be restored).