So let's have a look at the light meter. Every Tesla has a built in light meter. The light meter is your guide for your exposure before you take the shot. So the light meter is going to help us get to the middle of the exposure. We're going to find the middle of the exposure if we can find the middle of the exposure, then the white should be correct. And the black should be correct.

So let's have a look at how that works. I'm going to shoot the back of a camera now. So you can see what the light meter looks like and how it works with some adjustments. Now this is a Canon seven day is the camera I use for my general sort of photography when I'm out and about now On the bottom left hand side, you can see a little meter, which says minus three, minus two, minus one, and it has a center arrow. This is one plus two plus three, that is the cameras light meter, we're going to use that to find the middle of the exposure. And if we can find the middle of the exposure with that triangle, then we can know that our whites are good, and our blacks are good.

Now, this light meter is quite accurate. But we'll find that when we introduce another tool, which is the histogram, which we use, after we have used the meter, and we'll come to that into in the next lecture. We'll find sometimes this meter gets tricked. Now what's important to understand about light meters, is they take the whole scene And they will take an average of that scene, it will take middle gray in the tones. So it won't see color, it sees grace, and it and it will look at the image and say, the if I take all the little pixels from the image and I compare them, and then I average them out, what I'm going to find is my exposure. The problem is that when you use a light meter, like this, you don't always get an average amount of light in every image.

Sometimes there's more blacks, some that times is more white. And in those instances, the light meter fails to work accurately. But we can use the histogram to figure out how to adjust that back. And after a little while, it becomes very easy to use this light meter, and you'll even start compensating naturally without using the histogram. But let's just have a look. at how this works.

So we can see that there's a dial under the center spot. So this is saying this is exposed in the middle. Now we're going to be talking about stops of light. On the back of the camera, that one represents a stop of light, the two represents a stop of light and the free represents a stop of light. So if we now want to move that along, we're going to have to use one of the free leavers that we've got in our camera to control the amount of light that's coming in. And those free leavers are the ISO, the shutter speed, and the aperture.

Now, each camera, when you're in manual mode will give you the option of controlling one of those leavers. And we're going to go into this in much more detail. But you're going to pull one of those leaders up or down and it's going to increase The amount of light coming into your camera, which is going to change the light meter reading on the back. So let me show you how that might work. So initially, we're right in the middle. But if I take the shutter speed meter, and I take it up a stop.

And remember, don't worry about all these terms right now, or when you get to the stop lecture, this will make sense. That's why it's important to watch all the lectures don't just drop in and out. They won't make sense until you've gone through them all and then go through the course a second time. So what we've done here is we've reduced our exposure by stop and the light meter is telling us we've gone down a stop, so we're stopped under, so we're underexposed. Now if we go the other way, and we're one stop over. The lever we used was our shutter speed.

So we slowed our shutter speed down and we've gone up Whoa, stop. So that light meter, if we stick that in the middle, like so, when we take our shot, we know we're pretty close. That's how simple it is. Now, we might have to make some adjustments because the camera will only give us an average of the scene. And it might be wrong. It might be right, we don't know yet.

This image is right, because we've got an equal amount of tonal value. That's the way I've set this shot up. So we've got equal, if we added all the whites and the blacks and the grays together and average them out into one color, they would come out middle gray, that's how the center works is looking for middle gray. So the tonal value is good, we're in there, that's the meter. So that is what we're going to use before we take our shot to get roughly and it will be roughly because it can be a stop or even two thirds of a stop out and we'll show you in the next section. How to bring that back.

And how to compensate for that. But roughly, we have a correct exposure so when we pull in all those levers, so when we change in the ISO using the ISO button, we're changing the aperture using the aperture controls, or we're changing the shutter speed using the shutter speed controls. That arrow will move up and down. And it's telling us we're one stop over with too bright, but just right, we're one stop and we've tipped our seesaw that direction. If you bring that seesaw image back to mind now, when you're underexposed, you'll be on minus one because the seesaw tipping That way, when you plus one, you can be overexposed because the seesaw is now tipping that way, and you can bring it into the middle. So we've balanced the exposure.

And that is how you use your camera meter to balance your exposure.