Hi, I'm Tony Northrup and for chapter 4 of my book Stunning Digital Photography,
my daughter, Chelsea and I are
out at a baseball diamond to demonstrate why you
should learn to use back button focus. Back button focus is a technique that
stops your camera from auto focusing when you push that shutter button
halfway.
Normally you push the shutter button halfway, your camera autofocuses and then when it focuses
you push it all the way to take a picture. And that's awfully convenient
especially if you don't know how to use a camera.
But if you separate the focusing
and the picture taking, it opens up a whole new world of possibilities and
allows you to take pictures so much
faster. And one of the best examples of when to use this
is sports photography. But it's also terribly useful for
night photography, portraits, wildlife, weddings
candid shots. Just about anything you might do, back button
focus can make it better. So first I'm gonna show you just how much better
by taking a couple of shots my daughter here. Now,
she's batting and when she's at home plate I like to use focus recompose so I can
put hervright at the edge of the frame and use that rule of space to leave plenty of room in
front of her.
But when she's running down the baseline, my camera's auto focusing system needs all
the help it can get to keep up with her. So,
in other words when she's batting, I want to use single focusing,
known as one shot for Canon cameras or AF-S for just about anything else.
And then when she is running I want to use continuous focusing, AFC
or a just AI servo
on Canon cameras. And it would be a little tough
to switch modes while I'm trying to take pictures because
I don't know when she's gonna hit the ball, right, but as soon as she does I'd have
to switch modes and that could take a little bit.
So I'll demonstrate taking pictures without
using back button focus first.
Nice one, Mad. So there you can see, I
did manage to switch from single focusing to continuous focusing in a couple
shots before she got to
first base, but I'm also really practiced with my camera.
If you weren't quite so good at switching modes it would take you even longer.
But with back button focusing I won't have to switch modes cause I'll leave my
camera in continuous focusing
and when I want to do focus recompose I just hold down the
AF-On button or whatever but I've assigned to use back button focus
and I'll hold it down until the focus is on her on the mound and I can recompose
and not worry about the camera refocusing. Then when she starts running I'll just hold it
down and keep the focusing point on her.
Because it's already in continues focusing mode, there's no need to change modes.
So let's see how many shots I get using back button focus.
Great, awesome.
So you can see there was almost no delay there. All I had to do was to
put the focusing point on her and then hold down that back button focus. It took me
less than a second
and that gave me 10 times more shots
of her running down the baseline. So now that I've sold you on the usefulness of
back button focus, how do you actually get it set up? And unfortunately it's
different for
every single camera. All I can do is tell you to search
for the model number of your camera and the phrase "back button
focus" in, say, Google. So you might say "Canon 70D back button focus"
and you'll find somebody has nicely provide instructions for you. In general,
it can be a one step process or a multi-step process. Usually you have to find
the setting in your camera that turns off
autofocusing when you push the shutter button halfway down. Then if your camera
doesn't have a dedicated AF-ON button,
you need to assign autofocusing to one of the buttons on the back
of the camera. Those two steps are enough to allow anybody to use
back button autofocus. It's going to take some practice though.
You'll need to use it for a couple days until the muscle memory kicks in
and you learn to automatically focus using that back button.
And until you get to that point, you might miss a few shots, so I encourage you to set it up
and then practice practice practice. If you ever need to switch back
to your traditional focusing system, just put that camera over in the green mode or
fully automatic mode and usually the camera will override all of your
existing settings.
If you like this video please subscribe and click
like and for lots more instructional videos like this check out
chapter four of my book Stunning Digital Photography. which has more than seven
hours of video. You can get it at sdp.io/store
or at Amazon. If you have any questions please write a comment
down below. Thanks!