Two Exposures Explained: Ambient & Flash
So it is imperative that you understand what is happening inside your camera and flash, because the thing with the flash, especially these guys, the speed lights, it can go sideways really fast. It can really go sideways fast because there are so many different variables on and things happening that again from shot to shot. You see all these different things happening, and sometimes you get stuff. It's all blurry with a ghost floating through it. Like what is that and all that stuff? So we need to know what exactly? This Flash is doing exactly what the cameras doing so we can control everything. That's what we gonna do. So we need to start that one place. And that is this. When we add a flash, any kind of a flash. We had a flash to our camera on camera flash off camera flash the pop up flash flash of any kind. Anything that flashes one exposure becomes two exposures. That is the key. There are two different exposures. There is the ambient light, right? That's the light that sort of flo...
ating around out there that we can't control. We have the ambient light, and then we have the light that is coming from our flash And we have to control those two things independent of each other. And we can So we can say I want to have mawr Ambient light, less ambient light, brighter background, less background I wanna have mawr flash less flash I want the ambient light And not only do we have two different exposures we have two different qualities of light now to pay attention to So are ambient light can be hard light And our light from our flash could be soft light or the ambient light can be soft And the light from the flash could be harder They can all be hard or all soft And we get to choose all those things. The important thing to understand is there separate and we can control them independent of each other. And that's the fun that we're gonna do. Okay, so this first shot right here, flash exposure is the same. So you see, on Mrs Lucia on her face is the same brightness, right? The same amount of light on both pictures. But look at the tree in the background on this one. On the on the rights are left side over here. The tree is much brighter than it is on the right side. Okay. See how we were able to change that? And this really went like this. Click, click, click done about that fast. So we can control those two things independent of each other. And we can do the same thing with the light from our flash. So check this out. Now, look at the tree. The tree is the same. The same exact exposure. But on the front, we were able to change what our model of likes over here. Really dark under exposed. Not the appropriate. My light on the right looks awesome. Right. So, weaken, change those two things. Let's plea. Tend, by the way, we are at the beach. Okay, So this is water going down here. Jaws maybe. Are I can't drop anyway. That's jaws, right? Maybe. I don't know. We don't need just, um not the beach. We have a model with flowing hair flowing here. Okay. And then we have a tripod with the camera on it with a flash on the camera, something like that. And then we have big headed person right here taking pictures. Okay? So what will have Let's pretend that we have, um, a big, bright sun, Right? Here's our big, bright sun and it's blasting like, lasting, like this is, Let's say toward the end of the day. Okay. By the way, guys from Seattle, that's the sun. It's a big, bright thing that floats around out there at once in a while. Eso This is going to be lighting up all of this background right here. Now, if you take a picture normally with no flash, what will happen is the back of this person is going to be silhouetted, right? You're gonna have all this ambient light's gonna look great. And then this is gonna be a silhouette, and it's not gonna look so awesome or you're going to have a picture where the person is x Suppose in the background is just totally washed out, right? Totally washed out. So we're gonna try to do here is we're gonna turn on a flash. It's going to turn this flash on pure and that flash. What it does is it illuminates the front of the subject. Okay, so we have That's our two exposures, right? We have our flash right here. That's the flash. And then we have our light from the sun. This is ambient light right here. Okay, that's what we have. Now, this ambient light is something that is very interesting. So the ambient light and let me just show this year on the screen, we have something that we have to react to. The ambient light. Okay, this light right here and the reason because is that we can't always control it, right? The sun we can't control. There are clouds moving in and about things like that. Um, and because of clouds and the time of day, ambient light has this tendency to change on us. And so this light right here what we have to dio when we start, we have to say, Hey, Mr Camera, let's figure out what we need to do with this stuff here to get a good exposure. That's where we need to start. We need to say, how do we get a good, proper exposure with this? And then once we have that, then we can take our flash and adjust it so that we have something that Seaver either brighter than the ambient light or balanced with that or just a little bit under. But we have to start with this ambient light and make sure that it's good. And so we're gonna do that. Now we're going to start by looking at, which is gonna be a refresher for some people. But stick with me on this because once we figured this out is gonna apply directly to this and then we're going to start looking at how we can do that balance between those two things and trust me, you'll go. Oh, right, that's it. So we're gonna do here is Let's talk about this. How does the camera figure out how much light toe let in and how does it balance those three things? So somehow, mysteriously, when you put your camera on aperture priority mode a shutter prior to mood or whatever it knows, right? And even if you have it on manual mode, there's a little meter there that tells you what to set your dials and switches to, and somehow it knows how to tell you what it is and so we might know. And I'm gonna show you this thing right here and it is this that 18% gray is 100% of wacky. So what are camera does? Let me just show you with This is it has a little light meter inside there and it looks all the different light in the scene. All the darks, all the brights over here. It would look at it. You know, this white stuff here in this gray and this stuff over here, and it sort of puts it into a blender. It blends it all that are, and it averages all that. It throws all the color away averages those darks and brights and everything, and it expects everything to mix to a middle gray, which is 18% gray. Sort of like this background right here on this presentation. That's what it expects. And things can go really wacky because your camera is stupid. Okay, your camera is really stupid. OK, So what we're gonna do is we're gonna talk about this thing right here. This t t l meet during this is why people love light meters because they're not as dumb. They're still done, but not as dumb as your camera. And it's t tl metering. And so tt l by the way it stands for through the lens. That's what t t l is. So light goes through the lens, it goes into our camera. And guess what? Titi Also stupid, stupid. It doesn't know it doesn't know what you wanted to do. You have to tell it. You have to tell it what to do. And so let me show. You have this little diagram here to sort of illustrate what's going on. So through the lens works like this light comes in. That's a little yellow arrow. It travels through the lens. There it is. There's the mirrors inside this right here and these mirrors. What they do is this. 1st 1 allows, like to bounce up. There's this thing right here inside the viewfinders called a Pinter prism that allows, like to bounce around and come out. And that's how we see what the is coming through. The lens right. The light goes through there and we can see stuff inside up here in this little area right here inside the Pinter prism on most cameras, that's where the light meter is. That's where it is. It's right up in there. So as you're pointing the camera, moving it around, it's seeing everything you're seeing and it's saying, OK, let's mix everything up to that little gray and let's figure out how we should adjust our camera settings to get a proper exposure down here. Some of that light goes through this first mirror. There's a little second mayor there. That's your autofocus. That's what that is. Okay, so here's the problem. And here's where things happen with the flash that gets wacky and this is a preview. We're going talk a lot about this here in a second. When you take a picture, those mirrors open, and when they open, the light doesn't bounce around anymore. So this light meter doesn't see the light when your shutters, the mirrors are up in the shutters up. So when you're in, your camera's shutter is open, light meter shuts down. It can't see anything that causes all kinds of problems with the flash, which we're gonna talk. This is this is this is foreshadowing what that is