Thread: Back button focusing...who uses it?

Since getting the 7D I have been using back button focusing with ai servo (not always with). All I can say is if you have not tried it, give it a go it's fucking awesome and is IMO some what of a game changer for advancement. Takes a bit of getting used to but it is pretty intuitive.

Absolutely. Would not switch back. It's critical for shooting sports.

Who wouldn't?

+100. It felt a little awkward at first (started with my 40D a couple of years ago), but love it -- can never go back. Sometimes when somebody else gives me their DSLR to use, I wonder why the focus is changing when I start pressing the shutter button. Only downside is if I hand MY camera to somebody else to take a shot, I have to explain back button focus.

Only downside is if I hand MY camera to somebody else to take a shot, I have to explain back button focus.

I think it's a major plus for this some times. When some lady offered to take a shot of my wife and I at Morraine lake all I had to do was stand where she was taking the shot from, focus and hand it off to her and of course like most people she just mashed down the shutter button anyways, but since it was already focused = win. Was funny to see her reaction when it fired off like 6 shots since it was on high speed lol. I guess if you are wanting a buddy to shoot you skiing it could be a bit of a hassle where changing distance ect.

Yeah for sports it's fucking $$$$$$$

I think it's even more important for framing the focused element off-center and not confusing the camera.

^I have noticed IMHO that my compositions have improved as I can dedicate more "focus" on that aspect without having to reframe for each shot.

I know this post is a couple weeks old, but I haven't been on in ages. Personally, my favorite thing about back button focusing is that it lets you go seamlessly between single and continuous AF with no effort or wasted time.

If anybody hasn't tried this, by the way, set the shutter to focus priority (or whatever Canon calls it when the camera will only shoot if it's in focus), then prefocus on a spot, hold the shutter button, and it'll automatically shoot when the subject comes into frame. Freaking awesome for the motorsports work that I do, and I bet it'd be great for MTB or certain ski stuff.

^ what the hell?

I can't get that to work like that on my 7D. Maybe I don't have the settings right.

Been doing it for years... Fuzz sums it up well:

Originally Posted by Fuzz

+100. It felt a little awkward at first (started with my 40D a couple of years ago), but love it -- can never go back. Sometimes when somebody else gives me their DSLR to use, I wonder why the focus is changing when I start pressing the shutter button. Only downside is if I hand MY camera to somebody else to take a shot, I have to explain back button focus.

I've completely remapped all of my buttons so that no one can use my camera

Dof preview -> One Shot <-> AI Servo
AF On -> AE Lock
* -> start metering and focus
controller pad -> move the focus point
shutter -> start metering and release shutter
M-Fn -> electronic level in VF (boo yeah, this one is great!)

Tutorial on this just to add to the useful thread - http://www.learn.usa.canon.com/resou..._article.shtml

Based on the response of this thread, it sounds like I should give this a go. But I've never understood the true value. What's your guys take on these observations:

Originally Posted by tutorial

If you are shooting something like a series of portraits of a person, and you want them composed off-center, back-button AF makes it super-easy to take as many pictures as you want

When would I ever take as many pictures as I want? I may take one, move to a slightly different position (where I would need to re-focus anyway), take one, move... etc.

Originally Posted by tutorial

For sports photographers and others taking action pictures, back-button AF lets you stop focus whenever something might interfere with the moving subject you’re tracking

When I hold down the shutter half way, the focus stays where I initiated the focus. If something moves in front of it, it doesn't change the focus. Also, if I'm shooting sports, the subjects are always moving, and either I need to re-focus or use AI servo, no?

If I am in the same place shooting the same basic scene at the same focus (rarely to never, but for the sake of argument), I focus once and turn off AF. Is this technique basically an easier way of doing that?

Originally Posted by Natedogg

If I am in the same place shooting the same basic scene at the same focus (rarely to never, but for the sake of argument), I focus once and turn off AF. Is this technique basically an easier way of doing that?

This technique is a much easier way of doing that. You "turn off" autofocus by not using your thumb. If you only use your index finger then it's like having MF.

It's really nice in case you are tracking something, stop shooting, but you accidentally let go of your finger all the way. In that case, you have to reaquire focus. With back button focusing you can keep focus going regardless of whether or not your finger is on the shutter release. And THAT allows you to have the exposure unlock!

Gotchya. But one last stupid question:

Originally Posted by SchralphMacchio

It's really nice in case you are tracking something, stop shooting, but you accidentally let go of your finger all the way.

If your subject is moving, don't you have to constantly refocus anyway? Unless you're using AI servo, which I admittedly have not fooled around with much. I tend to pre-focus a spot and go for one all-or-nothing frame.

edit--does 'tracking' imply you're using AI servo?

Originally Posted by Natedogg

When would I ever take as many pictures as I want? I may take one, move to a slightly different position (where I would need to re-focus anyway), take one, move... etc.

What you're talking about makes sense for formal portraits. But when you're shooting candid shots with an off-center composition, you may shoot a burst (and also wait between bursts) to get the best expression/pose. With regular One Shot focus, you have to keep your finger half-pressed on the shutter the whole time in order to avoid "resetting" focus.

When I hold down the shutter half way, the focus stays where I initiated the focus. If something moves in front of it, it doesn't change the focus. Also, if I'm shooting sports, the subjects are always moving, and either I need to re-focus or use AI servo, no?

The first part of your statement applies in One Shot focus. But if you're in AI Servo, anything moving in front of the camera will make it change focus.

Back button focusing allows you to switch between one-shot focus and continuous (AI Servo) focus on the fly without fiddling with dials or settings. The back button sets focus -- that's it. Back button pressed and held = continuous focusing (AI servo). Back button pressed once = focus set and kept (no matter when you press the shutter to take a single shot or a burst, focus doesn't change).

The thing about back-button focusing is that you need to try it out for yourself to see the benefits. When I first read about it, I couldn't see why it would make any difference. Even when I first started using it, I didn't see the benefits for the first day or so. But after a few days of using it under different circumstances, I couldn't think of doing it any other way.

^truth. AI servo is always set on my camera since I do back button focus.

Understood. Thanks, guys.

Originally Posted by Fuzz

What you're talking about makes sense for formal portraits. But when you're shooting candid shots with an off-center composition, you may shoot a burst (and also wait between bursts) to get the best expression/pose. With regular One Shot focus, you have to keep your finger half-pressed on the shutter the whole time in order to avoid "resetting" focus.

Actually, if you're taking single shots in "Formal Portraits" you're doing it wrong, especially in the digital world where there's no/low cost to take oodles of pix. Too big a possibility of people blinking, looking away, or other small stuff that you're not necessarily going to catch when chimping. Always take 3-4 shots, shit... memory is cheap.

^ Seriously. Remote release with 5-6 bursts.

Originally Posted by Tippster

Actually, if you're taking single shots in "Formal Portraits" you're doing it wrong, especially in the digital world where there's no/low cost to take oodles of pix. Too big a possibility of people blinking, looking away, or other small stuff that you're not necessarily going to catch when chimping. Always take 3-4 shots, shit... memory is cheap.

You're right about using burst mode -- what I should have said (and meant to say) is studio shots where things are not moving can be shot with One Shot focus. I do always shoot burst mode when shooting people in formal and informal settings. Note that I was talking about using One Shot focus, not burst mode -- you can still shoot burst with One Shot focus, but the problem is you cannot let go of the shutter because the focus will reset.

Originally Posted by Fuzz

Only downside is if I hand MY camera to somebody else to take a shot, I have to explain back button focus.

Originally Posted by SchralphMacchio

I've completely remapped all of my buttons so that no one can use my camera

Man, this really bit me in the ass in J-tree last month. I also now only shoot full manual metering with spot metering, which screws up if you switch into "AV" to hand to someone because it's not metering the entire scene. I figured rather than switch all of my manual settings off, just go into idiot mode and hand the camera over.

But when I switch my camera into idiot mode, it goes to full all-points AF. So the person using my camera has no control over AF - so I have a lot of nicely composed images that my partner took of me tying into ropes, climbing, etc - in some of the most amazing light (late afternoon light in the high desert is unreal) ... and none of them have me in focus, more like bushes, or the climbing rope, or some really high-contrast rock features.


Hahaha ... the photographer always gets screwed whens stepping in front of the lens for a minute! One of these years I'll have nice climbing and/or skiing images of myself to show my kids ...

yes, if I don't have it it sucks

Originally Posted by Tippster

I think it's even more important for framing the focused element off-center and not confusing the camera.

This....

does anybody know if (and how) i can make this work on my sony slt? there is a dedicated "af" button on the back, but i think i cant deactivate the af on the shutter, except through switching to mf, and then i cant use the af-button on the back either. very stupid. dunno if i want to shoot skiing pictures without bbf.

freak~[&]