In this video I'll take a look at flash
sync speed... what it is why you should use
it, and when it might not be the best choice.
Hello I'm Gavin Hoey, and you're
watching AdoramaTV,
brought to you by Adorama...
the camera store that's got
everything for us photographers, and in
this video I'm gonna have a look at how
shutter speed can affect your images
when you're shooting with flash in a
small home studio..
Now one of the things I've noticed with
the more modern flash point transmitters
is try as I might I
can't get it over two hundred and
fiftieth of a second shutter speed.
I can have anything up to that but nothing
beyond it, and that's because the trigger is
actually helping me, it's limiting my
camera to its flash sync speed.
What does flash sync speed mean?
Well for that I need to look at the mechanics
inside of a camera, where I'll find a
curtain that covers a sensor, press the
shutter that moves out the way exposing
the sensor to light, and at the end of
the shutter time a second curtain covers
it up once again..
Now in reality it's a bit more complicated
than that, but that's basically what
happens and my flash sync speed is just the fastest
shutter speed where the whole sensor is
exposed, as the flash fires go beyond the
flash sync speed, and the curtains would
cover up part of the sensor when the
flash fires.... meaning I'd have a shadow or
part of the picture missing.
So if I can choose any shutter speed up to two
250th of a second on my
Olympus camera, yourl mileage may vary..
Which one would I go for?
And it's a really good question, and the
only way to answer that is...
to take some test pictures..
so I'm gonna set up two
different scenarios...
let's get some light,
set let's get a model in,
let's get shooting...
so to help me out today, I've got the
amazing Sophie.
Sophie is gonna be the
model for this shoot, and before I take
any pictures with flash I'm actually
going to take some pictures without flash.
To understand what goes on with
flash sync speed and your camera.
you need to take a few pictures to work out
what happens at different shutter speeds.
So to make this work I need to be in
manual mode that means I can choose an
ISO and aperture and of course most
importantly the shutter speed.
So I'm going to start with a shutter speed that
isn't normal in a studio... a quarter of a
second, and then I'll increase it up to
my flash sync speed, and check the
results.. let's have a little look so no
flash fire whatsoever, after quarter of a
second f/5.6, ISO 200... by chance,
the results are almost the correct
exposure for the
ambient light in the room.
now if I take my shutter speed up to a
15th of a second...
that's two stops less light, and
take the same picture Sophie is there
but it is starting to get a little bit
dark... two more stops adjustment will take
me up to a 1/60 of a second, and Sophie
is starting to disappear, and at my
flash sync speed of 1/250/th of a
second Sophie has completely gone,
and actually that's exactly what I'm trying
to achieve...
I'm really using the shutter speed just to
underexpose the ambient
lights. get that really dark picture
because the flash, is way brighter than
any room light you can have, which means
the camera will now only record the
flash ,and gives us an exposure that I've
got total control over... so basically when
it comes to your flash sync speed,
just set it the highest you can in your small
home studio, and everything will be fine
job done... sort of... so there may be times
when the flash sync speed isn't the
correct speed to use, so maybe you want
to include some of the room in your shot
or maybe you have an amazing setup..
a little bit like we've got here with
these glowing jars of LED lights.
Now if I was to use the same flash sync speed
as I used before... things might not go the
way I like.
I've already set the flash,
I've set the exposure correctly, let's
just take a test picture at the flash
sync speed.. see what we get.
So at the flash sync speed... Sophie is correctly
exposed.... the jars are there, but the LEDs
don't really look like they're glowing.
If I increase my exposure by two stops
the shutter speed gets a little bit
longer, which means there's more time to
record the LEDs which look slightly
brighter, but the exposure on Sophie from
the flash still looks exactly the same...
increase my exposure by another two
stops the LEDs appear even brighter,
but Sophie remains the same, and finally at a
quarter of a second, my longest shutter
speed.... the LEDs are really
bright, lots of time to record them...
and yet Sophie the flash exposure on her
still remains the same.
So this time you might think the correct
shutter speed is actually the longest
shutter speed.
It seems to make the LEDs bright, but
doesn't seem to affect the exposure on
Sophie... but if you do that, you run into a
couple of problems.
Yuu might get camera shake..
or motion blur where Sophie moves
even a little tiny bit, and that can ruin
the photos...
so to avoid any blur I'm gonna go with a
shutter speed over 1/60th of a second
but I still want those brighter LEDs...
so I'm gonna change my other settings,
I'm gonna go with an aperture of f/1.2 -
so much wider than it was before,
and a slightly higher ISO at 400.
Let's have a look at this result... so
the jars look bright, I like that, but so
does Sophie, and that's because ISO and
aperture will affect not only the
ambient light, but the flash that's
recorded as well.
So to adjust that I simply need to dial my
flash power down,
take the same shot again, and that looks
perfect on Sophie, because ISO and
aperture affect ambient and flash, but
shutter speed only affects the ambient
light that's recorded.
The reason that flash isn't affected by
shutter speed is all down to its super
short duration...
I mean the whole thing starts and ends in
thousandths of a second... it easily fits
in the window of opportunity that is our
mechanical shutter, the flash sync speed
so that's a technical bit out the way...
let's do something a bit more fun and
actually take some pictures in this
lighting.... so Sophie are you ready okay.
let's do it.
The vast majority of the photos I take
in my small home studio have a shutter
speed that is the flash sync speed...
but it's really good to know what
circumstances you might need to change
that... now if you're sitting there
thinking what about high-speed sync...
well that's the subject for another video...
if you've enjoyed this video or
you've got a question leave me a comment below.
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I'm Gavin Hoey thanks for watching.