The Exposure Diamond
When we're shooting in a studio, we have an exposure triangle that has to do with our flash, our flash exposure triangle. When we're shooting in ambient light on location without a flash, we have our normal exposure triangle. And those two things, we have to put them together to make a diamond. So to help you understand this, I've made a silly little chart here on my iPad. So we're gonna bring that up. So you can really see it, I'm gonna go away, and I'm gonna make this a little bit larger here. And let's take a look at our normal ambient exposure. That's the light that we can't control, the sun or whatever. We can control that with our ISO, our aperture, and our shutter speed. With our flash, we do something different. We use our flash exposure diamond. So that's the aperture, the ISO, and the flash power. And so if we combine those two things, we have a diamond. Now the thing to note here. I'll make this a little bit smaller, so I can pop back up on screen. The thing to understand he...
re is that two things are shared between these two exposure diamonds. And so if you change one of those two things, you're changing the ambient light and the light from the flash. So let me just walk you through that. And so what we'll do here is... Let me get my little scribbly tool. There we have it. Good. So we have our ISO, this guy right here, and the aperture. Those two things are shared between our flash exposure and our ambient exposure. So if we take our ISO and turn it up, make it higher, that's gonna make our camera more sensitive to the light from the flash. It's gonna make our camera more sensitive to the light from the sun or the ambient light. Our aperture value, you can make it very small. You can make it a very big aperture opening. That will also control how much light is able to enter through the lens from the ambient light, or how much light is able to enter from our flash into the camera. So it will control both things. So if we take our aperture and make it smaller, the exposure of our flash and our ambient light is both going to go down or up. If we take our ISO and increase it or decrease it, the exposure from our ambient light and our flash is both going to go up or down. Those two things change both exposures. So normally, you would set those two things and not change them, and then you would change these other two things, our shutter speed over here and our flash power. And those two things are gonna control the ambient light and the light from the flash. Why does the shutter speed only control ambient light? So remember that sink speed animation? All that stuff? The shutter is either fully open when we're at sync speed and the flash turns on and off, so it's as if the shutter isn't even there, or because it's moving across the sensor and the flash is firing multiple times with high speed sync, it still has no impact on the flash 'cause the flash is just repeating its exposure. So the shutter has no impact on our light from the flash, the flash exposure at all. It just changes the ambient light exposure. And the flash power, turning the flash up or down, so full-power, half-power, quarter-power, whatever, that doesn't change the ambient light at all because the ambient light is so much brighter than the light from the flash. Unless maybe you're shooting at night or something like that. But then you don't have ambient light. So the flash power is just controlling the light from the flash, and the shutter speed is just controlling the light that is their ambient light. And we can control those two things. So what we want to do here is we want to figure out how do we control these things in an intelligent way to get a repeatable exposure. And I have some things for you. So I'm gonna go away again. I'm gonna fade myself out here, and I want to show you some things that you can download. So we have two things. We have this one. This is our sync speed worksheet. You can download this, the bonus materials. I want you to download this and print it out. And I have created a system of figuring out how to correctly set the exposure. So the first thing that we would do is... I'll make this a little bit smaller. The first thing that we would do is we want to set our ISO value. When we're out shooting out in bright sunlight, normally that value is something like 100, as low as the camera can go. The second thing we want to do is we want to set the shutter speed. So this is, by the way, if we're shooting at sync speed or slower. So our second thing we want to do is we want to set our camera's shutter speed. And so because we're shooting at sync speed, on my camera that would be shutter speed of 200. The next thing we would do is we would look through our camera's builtin meter, and figure out what the correct exposure is for our ambient light. If it's really, really bright, it's probably something like F14 or something like that. So we'll just say that's F14. And now that we know what our aperture value is, we can meter our flash or use TTL metering so that the flash power matches this aperture value. So that flash power would be 80% or 20% or whatever, whatever it takes for our flash to meter at F14. So you can do that using the builtin TTL metering or you can do that with the manual meter. We're gonna do both things. So that is if you're shooting at sync speed. So in bright sunlight, you probably can't shoot at sync speed. And so we have a different way of doing this. And so what I'll do is I will get rid of all of these things here. ♪ Doo doo doo doo doo ♪ Sorry, I am messing up. There we go. So I'll get rid of all of those things. So the other thing we can do is this worksheet. This worksheet is what I call my depth of field worksheet. And so the way that this works is your priority is depth of field, so how much is in focus. So the first thing we're going to do is the same as before. We're gonna set our ISO. So we'll set that as low as possible. We're gonna start here at ISO 100. And then the second thing we're gonna do, we're not gonna do shutter speed. We're gonna set our aperture value. So if I want shallow depth of field, I might set this at F2.8 or F4. So that's 2.8. So I've set that. Then I can look through my camera, look at the ambient light and figure out what my shutter speed should be. So in this it's probably something like 1/4000th. Something like that. I don't know. It depends on the ambient light. So once you have that set, then you can set your flash exposure. So that flash exposure needs to meter the same as what we have here. So it has to meter at 2.8. So that might be 100% power. It might be at high speed sync. Whatever it is, this has to match that. And you can do that by using TTL metering or a manual meter. If you do a manual meter, it has to meter at F2.8. And that's how that works. So what we're going to do is... I'll shrink this back down here so you can see me again. So what we're going to do is we're gonna do both of these things. We are going to start by using our sync speed worksheet. We're gonna take this and we're gonna have Sidney come out. And we're gonna walk through these things, setting the ISO, the shutter speed, the aperture value, and then matching our flash to that aperture value to see what it's like to shoot without high speed sync. Then we're gonna switch over to our second worksheet, the depth of field worksheet, and we're gonna do the opposite. We're gonna open up our aperture, and then we're gonna figure out how to balance the ambient light, and then we're going to learn how to get our flash to match that exposure. And then we're gonna just play with changing the exposure of the ambient light and play with changing the exposure from the light from our flash. Because what we'll find out is that if you're using through the lens metering, which we're gonna use most of today, it might not get it exactly right. And so download these worksheets. Print them out. You might want to print several copies. So as we're going through these different demos, you can keep up with me by writing down exactly what I'm doing. Remember, when you are doing this in your location, the values are not going to be the same because the ambient light is not going to be the same. But if you know the steps involved, you'll be able to repeat this and it'll work just fine. Okay, so the next thing we need to do is we need to get a model in. We need to get our lights and everything set up and get shooting. So let's do that next.