So it's all about auto focus on today's
episode of
Hey there welcome back,
of course it's ask David Bergman.
I'm David Bergman, answering your
photography questions as always,
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Today I've got a question from Stephen R,
and he asks
"With the new Canon 1DX Mark III what is the best
focus method for a moving subject.
Ah the Canon 1DX Mark III, the brand new camera.
Right now as of early 2020 this is a
pre-production model of the camera, it's
just become available for pre-order so
I'm fortunate enough as a Canon Explorer
of light to have one, and I've been using
it for a while now.
Now you're asking about autofocus
settings, with this particular camera.
That's a real specific question,
and I am going to talk about a
couple of functions specific to this
camera, but I really want to talk in
general about using autofocus with
moving subjects that should work with
most DSLR cameras
Now one of the first things that happens
is people come to me
all the time, and they show me their
pictures and say, oh my kids are moving
around, and they're not in focus, and one
of the big reasons is the first setting
that you need to worry about when you're
talking about autofocus is...
on Canon it's called one shot versus AI Servo and
those two settings by default, out of the
box, the camera comes set in one shot
mode, and the way the autofocus works in
one shot, is the camera will hunt for
focus, and when it finds the subject and
it focuses on them, then it will stop
focusing, so it basically locks focus in
as soon as it finds focus on your
subjects, that's great with something
that's not moving, but if that person
moves at all, they're gonna be out of focus.
So for example I took Andreas
out here in the park, when I had him move
towards me, I had him running towards me
and when he's just standing still, the
frame is perfectly sharp, and I can shoot
away, but once he starts moving towards
me and starts running in one-shot mode,
you can see the focus stays back where
it was, it's not gonna move with him as
he runs towards me.
Now if I take the camera, and I switch
over to Servo mode,
now what's gonna happen is, while focus
is being activated, however you choose to
do that, and we'll get to that in a second,
but while focus is being activated,
as he now runs towards me,
that focus is going to continue to move
with him, and gonna keep
him in focus the whole time, and as I
shoot pictures, every one of those frames
you can see is in focus, the whole way, so
that's one of the big settings that for
some reason, it comes in the box in
one-shot mode, so you want to change that
if you're shooting anything that's moving.
Now another setting that comes
into play here is, what I call back
button focus, and for some reason they've
determined that the shutter button
should control two things, taking the
picture, and focus, I think that's a bad
idea those are two completely different
functions. so what I like to do is, remove
the focus function from the shutter, so
that the shutter will only take pictures,
and then on the back of the camera
there's a spot where it says AF on, and
there's a button there right where your
thumb tends to be placed, and if you, if
while you push down on that button by
default, it is set for autofocus on.
So if you're an AI Servo mode,
and using that back button to focus while you're
pushing down on your thumb button,
it's gonna be focusing constantly, so again as
he was running towards me I'm holding my
thumb down on that button, that AF on
button, and he's in focus the whole way,
if I take my thumb off of that button,
it's gonna stop focusing at that time,
so it's kind of like a focus lock, but much
easier to think about, because basically
when you're pushing your thumb down, it's
a, it's focusing, and when you let go of
your thumb it stops, it's really, it takes
up maybe a few minutes or maybe a couple
hours to get used to, once you're used to
it you really can't go back and shoot
any other way.
Now the next setting you really have to
think about with autofocus is your focus
point size, you can choose different size
of focus points in some of the more
advanced cameras like the 1DX Mk III.
So you can choose a very small focus
point all the way up to a large area, now
the smallest focus point is always going
to be the fastest, and the most accurate
in focusing, because it's only looking at
a tiny area of the frame.
When you use that little spot, that little area is
going to be in focus, the challenge with
that is if you use a tiny spot, you've
got to keep that sucker right on your
subject, because if you move off even
just a little bit, you can see it's going
zip out to the background really quickly
because it's only looking at that one
spot, and really nothing else.
Now most of the cameras have the option
to expand that focus point to a larger area.
In Canons case, they have two other settings
called AF expansion, and what that does,
you can see it's a box with a few little
boxes around it, and what that what
you're doing is telling the camera, okay
use that center point, but if I go off
just a little bit, use those outer points
and give me a break here, help me out a
little bit, so when I'm on Andreas
face here, if I move just a little bit
off you can see that it's actually
staying on him until I move completely
off of him.
So it just gives me a little
bit of a wider area to work with, that's the
mode I use 99.9 percent of the time when
I'm shooting any kind of action, sports
concerts, anything that's moving really
quickly, now there is another way to go
and that's called zone focusing, and
that's a wider area auto focus, where the
camera is looking at a much larger area.
The way that works is, is you're telling
the camera anything in that zone,
whatever's closest to the camera that's
what you want to focus on,
so you're giving up some control to the camera
there, or you're telling it that you're
letting it make the decision on what to
focus on based on whatever's closest to the camera.
So the challenge with that is if
something comes in front of what you
want to shoot, like for example,
when he holds his hand out in front of his face,
that focus is going to zip out and focus
on his hand, you may or may not want that,
but you don't have the control, you don't
have the choice to stay on his face.
If you're in that wide zone area,
if you're just shooting a group of people,
and you want it to focus on their faces
and just take a picture, that's fine,
but if you want the control I would
recommend using one of those smaller AF
expansion areas, and putting it right
where you want it, and then you don't
have to worry if he holds his hand in
front of his face, that you can still get
the picture with his face in focus.
Now the newer cameras again like this
1 DX Mark III, have some other really great new
settings like face detection, and head
detection and eye detection, and those
work really really well.
It's kind of changing how we shoot a little bit,
where now you can let the camera do a little
bit more, the 1DX Mark III,
also has People Priority Focus,
so it knows when there's a person there,
and if you have that turned on,
it will focus more, it'll put more emphasis
on focus when there's a person,
and the frame which is super, super cool,
there are a lot of other settings in
these cameras that, that I've done deep
dive videos before, but there are case
modes in here where you can change
things like tracking sensitivity,
acceleration and deceleration tracking,
and things like that, it really depends how
deep you want to get into these focus
modes to make those changes, but I think
I covered the big points, if you, if you
get just those things set up properly
you're going to make pictures that are
going to be sharp, no matter how fast
your subject is moving.
So thanks Stephen for asking that
question, I really appreciate it,
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