The Triangle: Aperture, ISO, Shutter
so we're gonna still keep tearing things apart. Okay? We'll keep tearing things apart in detail of what happens when the shutter opens and how ambient light and how flash is all exposed. All that kind of stuff. And so to start, we're gonna go even deeper. Okay? So to start with, totally forget about the ambient light, okay? Just forget about that. Pretend that there is no ambient light just for a second. All right, So we have three things in our little exposure triangle, right? Have aperture. We have a shudder. And we have I s o aperture controls, quantity, shutter controls, duration, and I eso controls sensitivity. Okay, for now, as we tear this stuff apart, we're gonna get rid of. This is so stuff. So we're gonna talk about these two things quantity and duration. Think of them in those terms. Quantity, duration. How much? How long? All right. So when we look at those two things, remember quantity, aperture, duration, shudder. When we look at these things duration, you will find it do...
esn't matter the duration when we're talking about flashed, Remember, we're not talking about ambient light anymore. We're just talking about flash duration doesn't matter. And why is that? OK, so to the shutter, the shutter doesn't do squat whips. The shutter doesn't do squat to control flash exposure. A. It doesn't. In fact, the shutter is going to cause all kinds of problems. It's a troublemaker. Why is that? So what's happening is the flight from the flash on Lee comes through the shutter when it's all the way open, which means it doesn't really even exist. I know this is sort of a hard thing to understand, and I have videos to show you this. Okay, so the shutter doesn't really matter to the flash at all. It like it doesn't even exist in the flashes brain. So let's talk about how the shutter works normally. Okay, so I have this little animation here and we'll watch that, and it's about 20 seconds. This is how our shutter normally works with no flash normal shutter, No flash. Here we go. When you press the shutter, release with your finger. It tells the camera to open the shutter. The first curtain opens to reveal the light to the camera sensor. Then the second curtain follows behind to hide the light. Then the curtains reset and wait for you to press the shutter release. Let's watch that again. Notice in this animation that the first curtain opens completely before the second turn begins to follow. This only happens in slower shutter speeds, usually speeds under 200 of a second. Now watch what happens when we speed things up. When the shutter speed is faster, the second curtain can't wait for the first curtain to open all the way. If it does, it won't make it across in time. Notice in this animation that the shutter is never fully open. It just reveals a slit of light as it travels across the sensor and the slit becomes smaller as the shutter speed increases. Okay, so I forgot to tell you the shutter is made up of two curtains, right? The first curtain in the second curtain and they move like we just saw. So, uh, there's this thing called sync speed. What sync speed is it's the fastest shutter speed that allows the first curtain to fully open. Okay, this guy's all the way open before the second curtain begins to close. So in the animation we saw that the faster the shutter is these two things start moving together. So sync speed is that speed where this guy, the first curtain can go all the way open before this guy starts to close. Most cameras, that is, around 2/100 of a second, maybe 2 and on your cameras. If you have a pop up flash or if you have a built in flash, you've probably seen this. You put your flash on, you turn on your camera and it stops at 200 won't go any farther, just like that's it. And it's doing that because of this thing called sync Speed. So let me explain why it stops there and why this shutter can cause problems. What happens is when you add a flash to the mix, things start getting wacky. And so guess what? I happen to have an animation all about shudder and flash. I know you knew I would. So let's watch this. And this is that same animation. But this time we're adding a flash in the mix. When our camera shutter speed is set to sync speed or slower. A few things happen when you push your shutter release button. The first curtain opens, and as soon as the first curtain is fully open, the flash fires. Then the second curtain closes. Normally, if we have our shutter speed too high, we'd have problems. Let's take a look. When you pressure shutter release, the first curtain will begin to open. But before it's fully open, the second curtain begins to close. When the first curtain is fully open, the flash fires just like it did before. But this time, part of the sensor is covered by the second curtain. This will cause our photo, have a black area, and the faster your shutter speed, the more black you'll have in your photo. Okay, now, this is for studio photographers. We all know this. We have this problem with that sync speed because you can and studio photography. You can get that you could make that mistake. The camera will make you let you make that mistake with their on camera flashes. The camera will allow you to make that mistake with using a sink speed that's too high. So back to this shutter thing. So why the shutter doesn't matter, so the shutter doesn't matter, because it's all the way open. When the flash fires, right? It is always open, right? Because we knew three things control exposure, right? I s o sensitivity. Shudder, but wait, shudder just went away. So we can't control our flash with their shudder. I know this is, like sinking, and I can see it. What? And we also have our aperture, right? So aperture can control flash because it controls quantity. So the aperture can say, Hey, not that much light, more light so it can control that. So what we're showing here is that because the shutter doesn't matter to our flash, we have to invent a new exposure triangle. And once weeks understand the exposure triangle for the flash, that's what we're gonna use to control our flash exposure. And then we're going to use our normal exposure triangle, which we talked about control and being light. And if you know those two things, guess what? Uh, now I can control ambient light and flash. That's how we do it. Right? Awesome. Okay, so I don't know. I said that said we're only talking about light from the flash, right? Right now, we're only talking about light from the flash. Don't forget that. Okay? So the question is this What controls flash exposure? I'm gonna call the output from the flash. That's what I'm gonna call so flash power output from the flash. Because guess what we can do. We can tell our flash to have more light or less light. We can tell it to increase or decrease Weaken do that, which is really cool. And so what we have now is this the flash exposure triangle? It's a new exposure triangle, which is really cool. And look, it looks just like the other one did. Sort of the aperture. We have the flash output and we have the I. So So let's take a look at these three things because we want to figure out something quantity, duration, sensitivity, right. Those three things. We still need those three things. So amateur controls quantity, correct flash output controls. What? I know It's a trick question. It controls quantity and duration. Ah, OK, I know. Uh, right. Can you see why it's so difficult to use these little speed lights Or, like, variable after variable after variable after variable? And so we're just breaking it down. So why is this quantity and duration? Let me explain it to you. Our flash has something called a flash duration. In other words, how long it's on quantity and duration. Flash duration is how short or how long that light from the flash is on. Now the cool thing about this, we will find out that you can freeze motion better with a duration of your flash. Then you can with your shutter. Let me explain that Here's the flash. Now here's the shutter, right? Let's say the shutter is zipping at 8/1000 of a second without a flash, and we're trying to shoot a baseball player, right? So it goes and Onley slices out 8/1000 of a second of something happening. But remember, our little flash can flash. It's something like 10/1000 of a second, or maybe even shorter. So if the only thing that the camera sees is the light that comes from the flash weaken sliced time out at these really, really small intervals and we can freeze motion better with the flash than we can with a shudder. These two guys quantity quality in duration again, we're not going to talk about our eso yet. We're gonna move on from that it's gonna be good. So what controls Ambien? Exposure, looking controls, the ambient exposure. We have this. We have shudder, aperture, and I s O. So what we're doing here is we're saying when you mix these two things together, flash an ambient light we have. So it affects both things. Aperture effects boast. Both things shudder. Onley affects the ambient light so you can change your shutter speed up or down. It's going to change your ambient light. It's gonna leave your flash alone because it doesn't affect it.