Hey we're talking about the difference
between mechanical and electronic
shutters on today's episode of
Hey everybody, welcome back.
Here I am of course as
always answering your photography
questions, don't forget to go to
AskDavidBergman.com,
submit your own photo questions there,
and I will pick the best ones to answer
right here on a future show,
today's question is from Mike P and
he asked what's the difference between
mechanical and electronic shutter on a
mirrorless camera, is mechanical better
for shooting sports due to rolling shutter?
Alright a lot of people may not
realize that actually in a lot of
cameras now you actually have two
different kinds of shutters, you can
shoot mechanical or electronic.
Let's talk about what they are and what
rolling shutter is.
Now let's rewind back
to the 35mm film days, all of
those SLR cameras had mechanical
shutters in them, basically there's a
shutter that covers the film and then
that shutter opens up, exposing the film,
technically there are two shutter
curtains, one of them opens to expose the
film, and then a second one closes up to
stop the light from hitting the film,
finishing out your exposure so the
amount of time that shutter was open, and
your film was exposed, meant your image
was brighter the longer that was open
right... so that's a traditional mechanical
shutter, and a lot of modern even
mirrorless and DSLR certainly have that
type of mechanical shutter.
Again with the, with a mirrored camera
with a DSLR, what happens is the mirror has to move
out of the way first, then the shutter
opens exposing the the digital sensor
now, in a DSLR instead of film, then the
second curtain closes up, and then the
mirror has to flip back down, so that you
can look through it, now on a mirrorless
camera with a mechanical shutter, there's
no mirror, so the way that process works
since the shutter is really sort of
always open, because you need to be able
to see that Live View image, there's no
mirror there, so the shutter curtain is
open, and then when you take a picture,
the shutter curtain actually has to
close down first, then like sort of
prepare to take the picture the shutter
opens, the second curtain comes and
closes, and then that shutter has to open
up again, so that you can then go back
into Live View mode and see, you know,
what's happening there in front of your
camera.
So that's the way a mechanical
curtain, a mechanical shutter works.
Now let me show you some pictures, a lot of
times when you compare a mechanical
shutter to a mirror, excuse me, an
electronic shutter, we talk about things
that are moving fast, cuz that's what's
gonna cause this rolling shutter that
we're gonna talk about, but I want to
show you first what a mechanical shutter
looks like.
Now to photograph some fast
action, a lot of times we like to use
things like airplane rotors or
helicopter blades, or something like that.
Something moving really really fast, now
instead of going outside and waiting all
day for a helicopter to go by, I took out
my drone, I have the DJI Mavic mini and I
took it outside and played around a
little bit in the neighborhood, and then
hovered it low to the ground and took
some pictures with different different
shutters.
So first I'm going to show you
here let's go into the computer, this is
with the Canon 1DDX MkIII camera, and
this is, these are pictures of the drone
now.
This is at 4,000 or 8,000 of a second,
actually sped up at some point
and you can see these images are what
you would expect from a traditional
mechanical shutter camera, and yes
there's plenty of motion blur on those
blades, but that's to be expected, they're
moving really really fast, so I don't
know what the RPMs are on that, but, but
it's I don't know, how fast you'd have to
go to be able to freeze them.
It would have to be insanely fast, but you
can see those those blades,
they look like normal rotor blades on that
drone, they're just a little blurry because they're moving
so fast, that's completely normal, so
that's the way a mechanical shutter
works.
Now let's compare that to an
electronic shutter.
What is an electronic shutter?
Well a lot of mirrorless cameras
use this, and what it is is, there's no
mechanical shutter curtain, there's no
physical curtain in front of the digital sensor.
All it does because that sensor
is being exposed to light when you're
looking through the live view, all it
does is it basically electronically
activates those pixels, and then turns
them off, right, I'm oversimplifying a
little bit, but that's basically the way
it works so there's no physical curtain
to block the light, it's just turning the
pixels on and off.
Now with that, there are some
advantages of doing that, some of the
advantages of electronic shutter.
First of all there's no, there are no moving
parts, there's nothing moving,
so if you were doing an
image like a long shutter, a long
exposure image, well you really want the
camera to be stable a lot of times.
If you're shooting with a DSLR,
you might lock up the mirror because that mirror
flipping will move the camera just a
little bit, well a lot of people don't
realize but the shutter actually because
it's moving can affect that as well, so
they call that 'shuttershock' right,
just a little bit of motion when that shutter
moves, so that camera shake is prevented
completely when you're shooting with an
electronic shutter, because there's no
movement, there are no moving parts, so
that's really cool, also you could shoot
silent, completely silent, since nothing's
moving, and it's just an electronic
activation, you could shoot completely, so
that's great if you're a wedding
photographer, shooting in a quiet... you know,
during a quiet ceremony, wedding ceremony,
or if you're a photojournalist working
in a courtroom or on a film set,
that's really really nice to have that silent
mode, and also in some cases you can
shoot even at faster shutter speeds
because of that, that mechanical process
isn't happening, there are some
electronic shutters that'll let you go
as fast as 30mm of a second, which is
really really cool to have if you need it.
Now there are some disadvantages and
Mike you brought up the biggest one, we
call it rolling shutter, now the way the
data is taken off of that sensor,
it scans those pixels one line at a time.
Instead of a mechanical shutter where
pretty much the entire frame is exposed
at once,
this is, it has to pull that data off the
sensor one line at a time, so if you have
a really fast motion, especially
something that's moving horizontally,
you're really gonna have some distortion,
and my friend Joseph Linaschke, has a
great demo, but basically you take your
arm and you, if you were photographing
your this arm moving left to right
really fast, let's pretend you know
you're in a moving car, and the tree is
flying by... as this is moving right, in
relation to the camera, the camera is
collecting data as it goes down, so if
this is moving as it's gathering that
data, and pulling that data off that
instead of being a straight line, all of
a sudden now, that actually probably be
this way, that tree or your arm, my arm
in this case, is going to be slow,
it's not going to be straight up, so we
call that rolling shutter, that's because
of the way that that data is pulled off
of the sensor, so that is definitely a
disadvantage with fast moving motion.
Now the other thing, you might have
another disadvantage, is you might,
have a thing called banding,
where a lot of lights
actually pulse, they, they pulse with
different color temperatures.
We can't see it with the naked eye, our brain
compensates for that, so we don't really
see it, we see it as a solid color, color,
but for example like the sodium vapor
lights in an old high school gym, or some
LED lights actually do pulse different
colors, and sometimes you'll see it if
you shoot bursts of images where each
frame is a different color, which seems
odd right, of a very, you know very fast
burst of a scene.
If you're seeing that, that means that light
is actually pulsing, so if you're using an
electronic shutter, and it's pulling that
data off one line at a time, the issue there is
you might see streaks of different
colors throughout the one frame, and
that's that's not ideal, so let me now go
back into the computer here, and I'm
going to show you the same drone, I
brought it out now, I brought up in my
EOS R, and I put it on silent mode, which is
the electronic shutter and you remember
what it looked like before with the
mechanical shutter with the electronic
shutter, ouch, this is what those blades
now look like, it's so bizarre looking
right, and the reason is again if you
think about the way that data is being
pulled off, those blades are moving so
fast that by the time the next line is
captured, is pulled off of that,
not captured, but pulled off of that
sensor, the blades have moved into a
completely different position, so because
of that it's really distorted, and just
really kind of funky right, it's kind of
a cool artsy thing, but not something I
would ever really use, so that is not
ideal for something moving that fast
right, so now Mike you asked me about
shooting sports from a practical
standpoint.
It really depends on the sport, if it's just sort of people
running or moving, it depends on the
camera, but, but you might not notice it
that much, but anything that's moving
really fast, the ball right, or maybe a
tennis racket swinging or a baseball bat
especially down at the end, maybe
people's hands as they're jumping or
something, you know, if you catch them at
the peak of the action, you might not
notice it, but their arms or their legs,
that are still moving,
you might actually see some distortion.
That is not ideal, I would say given the
choice I would shoot with a mechanical
shutter when I'm doing sports.
Now technology is changing right,
newer technology is helping to alleviate this
problem, all electronic shutters do have
rolling shutter because we don't
currently have a camera that has what's
called a global shutter, where it
actually captures the entire sensor in
one shot, there are no, that doesn't exist
right now in early 2020, but new
technology like the Canon EOS 1D X MKIII
actually has a brand new processor on
it, the Digic X Processor, and it is a
DSLR, but you can, it's sort of a hybrid
where you can shoot live view instead of
shooting optically, and that is you can
then choose if you want to shoot
electronic, or mechanical and so you kind
of have the best of both worlds because
now if you're shooting sports or
something, I mean it's a great sports
camera, you want to be shooting
mechanical, but even that electronic mode,
because that new Digic X Processor is so
much faster than older processors - it's
scanning those lines faster, and it's
minimizing that rolling shutter effect,
so it's not gone completely, like I said
every electronic shutter has that issue
but with newer cameras we're seeing it
less and less, banding is minimized and
rolling shutters minimize so that's only
gonna get better and better, so Mike I
hope that answers your question again.
I think given the choice if you can
shoot mechanical shutter for sports
action, sports action, I think you're
gonna be better off,
but as newer cameras come out, there's
gonna be, it's gonna alievate that
problem quite a bit, so thanks for
joining me everybody.
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