Aperture; Shutter Speed; ISO; & Light Explained-Understanding Exposure & Camera Settings Video Lecture | Capture like a Pro: Digital Photography Tutorial - Professional Skills

hi I'm Tony Northrup and for Chapter
four of my book stunning digital
photography I'd like to explain to the
relationship between shutter speed
aperture ISO and light they are all
connected to each other and adjusting
any one of them can be compensated for
by adjusting any other in other words if
you make the room brighter by raising
the lights you'd have to make your
shutter speed faster to compensate for
it it can be pretty complex and it can
be really hard to explain in writing
that's why I'm going to walk you through
a series of tests with my camera here
and this little lab setup that I've made
to show you exactly how everything works
what I'd like you to do is to watch this
video from start to finish and then
setup something similar in your own home
all you need is a dimmer switch once you
get some hands-on practice with it
you'll start to make more sense now
understanding these is important because
not understanding them can cause a lot
of problems with your photography shaky
pictures are not getting everything in
focus that you want to and once you get
an understanding of it you'll be able to
fix those problems
noisy pictures too so let's get started
by taking our first picture on totally
automatic mode the mode I'm using now is
the program mode which is p on most
cameras and it lets the camera make all
the decisions for you and if you're ever
unsure about the settings or you're
giving your camera to somebody who isn't
a competent photographer send it on P
mode and it'll take care of everything
for you it's a great way to go when
you're feeling a little bit nervous
about your photography however for those
of us who master shutter speed aperture
ISO and light its a mode that you won't
ever want to use because you always want
to be able to control those conditions
so you can see the camera does just fine
what I'm going to do now is to cut the
lights in the room by about half and
I'll take another picture
now as you can see the exposure didn't
really change between those two pictures
the brightness of the picture is exactly
the same and that's because the camera
Auto exposed it it looked at the light
and the room and adjusted the ISO
aperture and shutter speed in order to
get a well exposed picture
however those had a side effect as
you'll notice the fan is a little more
blurred than it was in the previous
picture and that's because it had to use
a longer shutter speed to expose the
picture properly with even less light
that's one of the reasons you need to
understand these because you might or
might not want that extra blur in there
and you do have total control over it
now you also notice that the brightness
didn't change and a lot of people think
they can change any one of these
settings and it will adjust the
brightness of the picture and automatic
mode it's not true
you can adjust the ISO or the shutter
speed or the aperture or the light in
the room and the camera is always going
to adapt to it so changing any of one of
those won't change your brightness to
interchange of brightness use exposure
compensation and in most cameras that's
controlled with a dial on the back
though sometimes you need to press an
extra button or go into a menu system so
just for an example I'm going to add a
stop of exposure compensation so we can
see the difference
as we can see there the picture did get
brighter it got one stop brighter to be
precise because I adjusted the exposure
conversation by one stock now a stop and
photography is a doubling or halving of
the light if you double the amount of
light in the room you've added one stop
of light if you cut the shutter speed in
half if you go from one 250th of a
second to one 500th of a second you've
increased the shutter speed by one stop
now
I'm going to move the camera into manual
mode whereas the ISO aperture and
shutter speed were all unlocked so that
the camera could adjust any of them when
I have it in program mode in manual mode
I can lock down everything and prevent
the camera from making any automatic
decisions it gives me complete control
so that's what I'm going to do and I'm
going to set it in manual mode and then
configure it so that it will expose the
picture properly and we'll take a test
shot
but I did there was I set the camera to
manual mode a shutter speed of one one
thousandth of a second f28 and ISO 6400
those settings together allowed the
camera to expose the picture decently
and you can see that blade of the fan is
just about frozen because one one
thousandth of a second is pretty fast
you can also see that the objects in the
background my dad the cue balls and my
book they're all pretty well blurred
you'll see in some later pictures those
will get sharper and sharper the first
thing I'd like to do is experiment with
changing the ISO ISO which by the way is
not an acronym you can look it up ISO is
the sensitivity of the camera's sensor
if you increase the ISO from say 100 to
200 you're increasing the ISO one stop
and that's doubling the sensitivity of
the sensor the typical usable range goes
from about 100 to 6400 so this was at
6400 which is a pretty bright ISO
because this room is pretty dim so I am
going to drop it down to 3200 and we'll
see the effects
as you can see the picture got darker as
your ISO gets lower the camera gets less
sensitive and if you don't let the
camera adjust the other elements the
aperture or the shutter speed
automatically then the picture is going
to get darker so let's move the ISO up
two more stops to 12,800 and see what
the effect is
as you might have guessed the picture
got brighter because we increase the
sensitivity of the camera without
changing any of the other settings and
we've been in manual mode where we
locked all the settings except for the
one that we were controlling now I'm
going to switch back to program mode
which will make everything but ISO
automatic and I'm going to take a couple
of shots at different ISO so you can see
the effects you can see here that the
camera exposed the picture at 1/350 of a
second and f56 and it was well exposed
now I will drop the ISO to 3200 that's
dropping it to stops so the camera will
need four times as much light and as you
can see the picture is still well
exposed but the camera had to change the
settings to one 180th of a second and
f/4 increasing the amount of light using
the other factors and as you can see a
result of the longer shutter speed the
blades got more blurred now I will drop
the ISO way down to ISO 100
and as you can see because it's an
automatic mode I can change the ISO to
anything and the picture is still
properly exposed but let's take a closer
look at those pictures and we'll see
some really important differences as we
get really close to those pictures will
see that the pictures at the high ISOs
are really what they call them noisy and
noise is the digital equivalent of film
grain and it's not pleasant it's
something to always be avoided now if
you look at that iso 100 picture you can
see that it's nice and clean and
beautiful iso 100 is almost always
better than the higher ISOs but one of
the challenges of photography is that
when you choose a low ISO you're going
to have to change some of your other
settings such as the shutter speed and
aperture as well now let's take a look
at the shutter speed you can control the
shutter speed by putting your camera
into shutter priority mode on almost all
cameras that's marked by an S on Canon
cameras though it's marked by a TV now
when you put your camera in the shutter
priority mode it gives you control over
the shutter so you can specify how slow
or how fast you want it and the camera
will change the other settings for you
most notably the aperture and perhaps
the ISO if you have it set to auto ISO
to allow the picture to be exposed
properly when are you shutter priority
mode anytime the speed of the picture is
important to you if there's a moving
subject in your picture you want to
switch it to shutter priority mode so
guess that your kids basketball game if
you're taking pictures of your dog
running or a bird flying those are all
times you want to be in shutter priority
mode so let's take a picture with the
default settings and shutter priority
mode
so at one 250th of a second the fans on
that blade are pretty well blurred now
let's imagine that I wanted to be able
to show those fan blades nice and crisp
I'm going to crank that shutter speed
even faster so let's jump up to one one
thousandth of a second
that's better they look nice and sharp
but what if that isn't the effect you
want what if you want to show motion
blur this is really common if you're
shooting a moving car for example you
got to get some spin showing in those
wheels and if your shutter is too fast
you're going to freeze too much motion
intentionally showing blur is one of the
tricks and one of the benefits of using
shutter speed so let's drop that down to
one sixtieth of a second and see the
effect
there's that nice blur I wanted at that
speed the fan blades are a complete blur
shutter priority gives you a control
over just how much motion your pictures
show
there's also motion in your own hands
and if your hand holding a picture and
it's ending up blurry
it's probably what they call camera
shake and you can control that by using
shutter priority and specifying a
shutter speed that's fast enough for you
to handhold check chapter 4 for detailed
information about avoiding camera shake
chapter 5 as well now I will show you
what happens when you change the lights
shutter speed gives you control over the
shutter and the camera will not change
it the camera will change the aperture
and if you've chosen auto ISO it will
change the ISO as well but it will never
ever change the shutter you have control
over that so I'm going to drop the
lights in half and we'll see what the
camera does differently
as you can see when I lowered the lights
in the room the camera compensated for
that not by changing the shutter but by
lowering the f-stop number choosing a
lower f-stop number opens up the
aperture the iris of the camera letting
more and light in it had to do that in
order to get the picture properly
exposed but in shutter priority you
control the shutter the camera controls
the aperture so let's take a deeper look
at aperture now I'll switch the camera
into aperture priority mode and take my
first picture
I took that first picture at f/8 which
is a pretty moderate f-stop number now
one of the things that aperture controls
besides the amount of light that gets in
through the iris is the depth of field
now there are other factors that
influence depth of field as well and I
describe those in chapter 4 but for the
sake of this we're only controlling the
aperture so at f/8 I got the objects in
the background kind of in focus but
let's say I want them nice and sharp
what I'm going to do is to choose a
higher f-stop number so let's crank that
f-stop number up and crank up the
background sharpness to
now at f32 I have enough depth of field
that you can read the title of my book
in the background I control the aperture
in aperture priority mode the camera
doesn't do it so let's imagine that I
don't want to see the background in
focus let's imagine I want a nicely
blurred background this is really
popular in portraits we're having a nice
blurred background helps to eliminate
any distractions to do that I'm going to
choose a low f-stop number because a low
f-stop number means low background
sharpness let's crank that down to f28
and take another picture
at f28 that book is completely blurred
and even my dad in the middle is pretty
blurry now you also notice those fan
blades got a little more distinct that's
because the camera chose a faster
shutter speed because it was using a
larger iris a larger aperture which let
in more light and that's how aperture
works now there's one other thing that
I'd like to show you and that's how a
flash can control the amount of light in
the room totally automatically so I'll
attach a flash to the camera now
now as you can see the flash had an
interesting effect on the fan blades it
kind of froze the motion but then you
can still see some blur when the flash
actually fired the imprint of the blades
at that current position were burned
into the sensor but because they were
moving the rest of the time the shutter
was open you see this kind of
interesting effect where they're blurred
and then frozen almost like a ghost
moving into position
it's one of the cool tricks that you can
do with flash now why might you want to
use a flash and add light well first you
might want front lighting if the subject
is backlit a front light would help fill
in any shadows so check chapter three
for detailed information about
controlling your light you might also
want it because you're not happy with
the compromise of ISO aperture and
f-stop given the amount of light if
you're forced to use ISO 6400 and you
just hate how noisy it is put a flash on
add a little light to the room and
that'll let you use a lower ISO if you
liked this video I hope you'll check out
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free to contact me at Toni at North org