Stops of light This is the key to understanding manual exposure. The problem with stops of light and the information that's out there on the internet is often that people don't understand all the different measurements of those three different leavers. So imagine those three different leavers each have a knotch each one of those notches. The measurement, although it's the same is called a stop is communicate in a different way. So let's have a look a graphic that's going to help us to understand how each of the leavers is measured. Now, if we come back to the triangle, we've got ISO, we've got shutter speed and aperture.

What we need to understand is what's called stops of light. Now, if you remember when we looked on the back of that camera, and we was looking at the little light meter, it was saying that a zero or centerline and one to minus one two, that's a stop of light. Now, the ISO measures stops of light. And we'll talk more about each of these individually in these measurements, so often it'll start at 50. On some cameras, most consumer level cameras are going to be 100 ISO, it's gonna be the first ISO. So then we're gonna move up to 100 ISO, that's the next stop.

And then we go up to 200. And it's a little bit confusing because there were 400 and 816, hundred and four and if you notice it doubles every time, but each one of those is only one stop and that throws people but if you can learn this chart with the ISO starts at 50, your camera's probably 100 and then it will go up your camera Stop at 6400 more modern cameras go to 12,800. We'll talk about that a little bit later when we talk about ISO specifically. But you can see each one of those a stop, and then we come to shutter speed. Now this really throws people out because this, the large number is the start. And that's the fastest.

And then we have it. And then we get to 121 25th. So you can see we go 818 thousandth of a second. So one 4,000th of a second one 2,000th of a second, one 1,000th of a second, on 500th of a second one to 15th of a second one on 25th of a second, then it jumps to 160, which doesn't quite work out. But that's the next measurement. One 120 fifth 160 on 3115 one eight, so it doesn't split half but it splits close to half and then it was rounded up or down.

Every time we adjust the shutter speed by one of these measurements, we have adjusted the stop of light. And then we have aperture and aperture is strange as well because the lowest number is the starts at F 45 is the smallest aperture, we want to add another stop, we go to F 32 want to have another stop, it's 22 and 16 and eight, all the way up to F on. Most people have a lens. Usually that's about f 1.4 or F two around that. Now one thing to bear in mind with aperture is first of a stop on aperture can be seen on the back of the camera. But what we're showing here is single stops of light.

So these are the things you need to learn to adjust those leavers by a stop every time. Now the aperture is gonna work. Ours to do some very tiny adjustments. But what we're interested in is the pure stops is the one the two not the little notches in between 1234. So F 45, f 32, f 22 f 16 f eight. That's what we're interested in.

As to the naming conventions, go and have a look online ISO comes from film shutter speed is is is obviously time. And aperture is obviously a mathematical term for the size of the iris in the camera relative to its actual size itself. So that can be a little bit confusing, but all you need to know is that each one of these is a stopping light. So we police leavers while we're using manual, if we adjust ISO by one stop up or one stop down, we're going to get those in And if you remember in the previous moment of showing you how we use the meter and the histogram, I was adjusting that by a third at a time but I was always using the aperture for that. So what I'm going to do now is I'm just going to bring the camera up and I'm going to show you where we adjust those on the back of the camera and how that each one of those stops is going to do the same thing.

So let's post some of those leaders and see what happens. Okay, so here we are, we're in the middle. And what I want to do now is adjust the meter by a stop. Now I'm already at my maximum ISO. So let me take it down a stop by changing my ISO. So watch the ISO numbers at 6400.

If you remember the chart, we are going to go to 3200. Now there is ISO settings in between Now we've gone down one stop, that was the ISO. So that was one of those leafers. So we've pulled that lever, we've gone down a stop. Now what I'm going to do now is use the aperture to go down, it never stops. So let's pull that lever.

So I've gone from F 5.6 to fa, and if you can see that, that little eight over there. So now I've just pulled the lever and I've gone down and never stop. But hopefully you can see that I just pulled that lever, and we've gone I never stop. So now let's see if we can get our exposure back by using the last lever, which is our shutter speed. So now we've adjusted from 30 to eight. And now we're back where we started and we pulled those free, leave it