In this episode learn how to introduce more ambient light to your flash exposures.
AdoramaTV presents Exploring Photography with Mark Wallace.
Hi everybody welcome to another episode of Exploring Photography right here on AdoramaTV, I'm
Mark Wallace. Well this week we're going to be talking about two exposure triangles.
The exposure triangle for ambient light, it's the normal old exposure triangle we all
know and love and the flash exposure triangle. There's actually two different
exposures happening at the same time. That's right when you add a flash to
your camera, one exposure becomes two. You’re getting the ambient light, that's
all the light that we can't control. Things like the Sun and these lights
that you turn on inside your house and you’re getting exposure from the flash. Now we
all know about the normal old exposure triangle, it has the ISO the aperture and the
shutter but the flash exposure triangle is a little bit different. Now it also
has the ISO because they camera's ISO determines how sensitive it is
to light. It doesn't matter if it's like from the flash or ambient light and
we know that the flash has to have its light go through the aperture so those
two things are in common between the exposure triangle and the flash exposure
triangle, but when we get to the shutter, well that's where things turn around
just a little bit.
The reason for that is that the shutter in your camera really has no impact on
the flash at all. It's like it doesn't exist. Well, why is that?
Well it's pretty simple when you're using a speedlight in a normal mode not
high speed sync when we get there that's different. We’re not going to talk about
that, but that's an exception, but when you're using your flash in a normal mode
or using a studio flash things work like this. When you press the shutter
release on your camera, your shutter opens and when it's fully open that's when the
flash fires. Now what that means is because the
shutter is completely
open its just like it doesn't exist at all, which means it can't have
an impact on the flash. So what's the third thing that impacts the flash? Well
it's the flash power. The output power if its at full power or half power or quarter
power etc. So our flash exposure triangle is ISO aperture and flash
output and so that means that you can control your flash output and the
ambient light output, or not the output but the exposure, the flash exposure and
the ambient light exposure independently of each other. You can make the ambient
light brighter or darker and you can change the flash exposure brighter or
darker. Now changing the flash exposure we've probably done this a million times you
just adjust your flash output up or down or use flash exposure compensation and
it works terrific but to change the ambient light we need to change our
shutter speed and we can really effect how our ambient light is in our photo. Now
to explain all this it's really sort of difficult to do that in the studio so
we're gonna go outside and I'll show you exactly how it works. Well now we are outside I’ve put a
jacket on and this sort of cold weather out here in Gavin's backyard and I've
asked Brian to join me. You might remember Brian from some of my previous
episodes. So now we're going to walk through how the shutter will allow us to
increase the amount of ambient light that our camera sees. Remember the
exposure triangle is ISO shutter and aperture so I have my shutter at a
180th of a second. My aperture is right now at about 4. Aperture of f/4 and
ISO is at 200. So with those settings I'll turn off my flash, Brian look straight at
me, I'll take a picture and you can see that the ambient light just doesn't
really exist. It's totally underexposed. Now remember the flash exposure triangle is
ISO, it's the aperture but it's the flash output. Now when I turn on my flash this
flash is going to use its through the lens metering to give us a proper
exposure so the light that we're seeing here. Bryan look right at me, is just the
light from the flash and it's pretty obvious because Brian has that really
flat flash on the camera
look. So how do we introduce more ambient light? You don't want to change the ISO, we
don't want to change the aperture because that is set for our flash its
all good, but if we start slowing down our shutter, watch what happens. So I’m going to
slow this down a couple stops, we’ll take a picture here. You can see now that some
of the ambient light is creeping in. I’ll slow this down a couple more here, so now
we're at 45th of a second and you see more ambient light, let's keep going
down here so now we're getting to a much slower speed thats 124th of a
second and you can clearly see there that we have a lot of ambient light and
because we have so much ambient light the flash doesn’t have to work so hard. So we are
just taking that down a little bit. Look at that. Thats a 12th of a second and now we can see the
garden and all of that kind of stuff because the cameras on a tripod, because
the background isn't moving. We don’t really have worry about camera shake that
much, and because Brian is being frozen by the flash we can sort of get away with that
slow shutter speed, so taking that shutter slowing it down will
introduce more ambient light. Well there you have it, as you can see changing
the shutter speed effects our ambient light. Now I've skipped over a few things
as this video would be 20,000 minutes long.
Specifically high-speed sync but don't worry that is covered in another video
that I did. You can find it at Adorama Learning Center and you can see it I've added a
link in the description of this video and one more thing that you
might want to know and that is sync speed, that is the fastest speed you can use
when you're flashes on your camera. I've also described how all of that works in
groovy animations so you can check that out, again in the description of this
video there's a link or just go to the Adorama Learning Centre. Speaking of the
Adorama Learning Center you should check it out there are hundreds of videos
they're absolutely free and if you don't wanna miss a single episode
well just click the subscribe button. Why not it's absolutely free and that way
you don’t miss
anything. Thanks so much for joining me and I will see you again next time.
Do you want great-looking prints at low-cost? Be sure to visit our easy to use online printing
service. AdoramaPix has professionals who treat your images with the utmost
care that you can count on.
For a quick turnaround on photos, cards or albums use adoramapix.com