 So a lot of my friends ask me, Shane, how can I take better photographs? And one of the things I always say is that people should try to understand the system behind photography in order to be able to really control their camera in a really effective way. And that's really kind of the key to taking good photographs, is being in a good working relationship with your camera. To do that, you really need to understand stops. Stops are super important. And stops sounds like sort of a funny word, so I'll kind of talk a little bit really quickly about the origin of it. It comes basically from f-stops, which is kind of a measurement of your aperture, sort of one way of measuring how open your aperture is. But stops has also come to be sort of shorthand for the amount of light in an image and differences in the amounts of light in an image and a way of measuring your exposure. So how about we talk about what the different stops of light are? And I'll try to show you sort of, I'm going to build sort of a diagram to help you understand what stops are. So let's take at first a real quick look at aperture. So when you have a lens, you have a certain amount of openness that has different settings. So, for example, the most open that you can make, a very expensive lens, for example, is .7. That is just a measurement, it's just a number, it's just .7. Then the next stop up from that is 1, and then it goes to 1.4. From there it goes to 2, from there to 2.8. And there are lots of stops in between along the way. These aren't the only numbers. So between, for example, 4 and 5.6, there is a 4.2 or 4.5. There's lots of different numbers in between all of these. And actually, it's kind of funny when I was looking at some photographs earlier today, though, I realized that I stick to these numbers often, which are basically the traditional f stops that you have on very old lenses. New lenses have little tiny increments in between them, so they'll have two stops in between each of one of these, or two, or called third stops. They're not full stops, it's a really important distinction there. So each one of these is called a stop. So you have 1, 2, 3, 4, you know, you're just going down. You have each one of these things being a stop. And I hope that this is okay to read. It's kind of a little bit confusing. All right, now we're going to take a look at shutter speeds. So we've got shutter here, and we'll use yellow for this. And we're going to start at a quarter of a second, so a quarter of a second, and then you're going to move up to an eighth of a second. From there you're going to move to a 15th of a second. Then a lot of you guys should understand after a 15th of a second, it's going to go a 30th and it's just going to double. All the way up basically, except there's a few spots like this right here where it kind of, there's a little bit of messy math where it goes from a 60th to a 125th. But, you know, we're just going to look over that and ignore the fact that it's not exact math. It's about, it's an estimated math. And then right here we've got up to a 500th, and then to here to a 1,000th. All right, so the thing is these are all shutter speeds, but they're also stops. So a stop in the, in the turn, in the way that it's kind of understood as measuring light is actually just a measurement of the percentage of light as you're going up. So right here you are cutting your light in half. Right here you are cutting your light in half. Each stop represents cutting your life and cutting your light in half or in the other direction doubling your light. So if you're going in this direction, you're adding more light to your exposure to your image. So either way you go, each time you're doubling your light or cutting it in half. Also, same thing is going to apply for ISO. So ISO is going to be measured in increments. Often you'll see lots of different. There's smaller, there's slower films and faster films on these and there are between steps too as well, just like with all this. But generally you're going to see 100, 200, 400, 800, and 1600. And see how it's doing the exact same thing. The number is doubling. So 100 times 2 is 200 times 2 is 400 times 2 is 800. And that is just exactly the same as this right here. So when you have go from 1600 to 800 you are doubling the, or sorry, you are making the film half as sensitive. So this is actually cutting down on the sensitivity of the film which is sort of the receiving end of the whole situation or of the sensor. And here in this case from 100 to 200 you are doubling the sensitivity of the film. So the thing is when you have all of these different steps you basically for every image you're selecting a set of these numbers, a set of these settings and creating an image with it. So say we were like in kind of a dimly lit room and you were taking a portrait of someone maybe sitting at a table or something like that and there wasn't a lot of light. A setting that you might use for that sort of situation might be f2.8. You might be at, if you have a little bit of light maybe you're at a 60th of a second. And maybe you're shooting it on low ISO film for some reason. So that might be your setting. So all of these things are a combination that create that stool that we were talking about in the exposure lesson. If you haven't seen the exposure lesson I would recommend checking that out if you can kind of imagine all of your settings as being a part of a three-legged stool. And if one of them is too short or too long the stool tips over so you want your exposure to be correct. Now what would you do for example if you wanted to have a shallower depth of field what would you do? Well you would move your setting here you'd cross out your 2.8 and say you'd select a 2. Well that just changed your stool. One of your legs is now is now a little bit longer or shorter depending on how you want to use the analogy. And so now things are out of balance. Now you're actually going to have an overexposed image. It's going to be too light because more light is coming in. You have increased the amount of light coming into the camera. You haven't changed your ISO or anything. So what can you do? Well one really great thing you could do is just move your shutter speed one stop. So you just go up the other way. So you're going moving this way here and the other on the other setting you're moving in the other direction. Now you can also for example we can undo all of that here. Let's see here. Undo that change. One thing you could also do you've made your you've allowed more light into the camera say you wanted to keep this shutter speed for whatever purpose and for whatever artistic purpose or something like that. Well then you could cross out your 200 theoretically on a digital camera and just switch your digital camera to 100. That's going to make the exact same exposure because you have added a stop of light here and you have subtracted subtracted one stop of light here. So this is really just simple simple math. All it is is just ones and ones and twos and threes essentially if you understand if you memorize each one of these steps. So if you just take a look at these numbers memorize these numbers and in some ways you'll you might have to memorize the ones in between them at some point but if you memorize these numbers and you memorize that just simply that each one is a stop away from each other. Then it's just a simple set of math if you if you switch for example from 2.8 to 5.6 and you're going to know that you need to go one to one to it's really simple so the last couple days I've been walking around trying to figure out a way that I could explain and show you what stops of light look like and how they work and if I had any images of that and then I was just packing for a trip this morning so you can see all my stuff laying out on my bed here and I looked down and the light was shining it was morning light was shining in on my bed and I was like oh hey that's two three stops of light right there I should I should talk about that. So how about we take a look then at what I did here. My foundational settings for this so I didn't change these settings I only changed my shutter speed so I'll show you how this works. I shut I set an ISO of 200. And my f stop is f4 so those were the things that I didn't change what I what I did change was my shutter speed. So here we are at 100 and 25th of a second. Hopefully you can read that then I moved one stop to one 250th I moved another stop to a 500th and then I did one more stop just for just for the heck of it to a thousand so you can see here the light intensity falling on the objects on my bed is different so here the window you can see the window is kind of the light coming in from the window is kind of being cropped by the window frame here and so it's kind of landing on my bed just like that and this little spot right here is in this exposure really really hot you could say it's overexposed it's hot and then you look down here and everything is properly exposed so the proper exposure for this part of the bed is actually right about here I mean I just about just about nailed it on that it's not perfect but you know it's it's about right now that though makes the problem has gives us the problem of this right here so it really is important in a great way it's a great way of showing you how the intensity of light falling on objects can change your exposure so here we've got basically in some ways almost two photographs now if you look over here to the right you can see at the 500 point at the five one five hundred mark is about where I've hit the proper exposure up here so you can see then that there is one two stops of difference between the correct exposure for these two scenes that's two stops where you're really going to have sort of a situation where one thing is either going to be blown out or one is going to be too dark which is going to be it's going to be underexposed so one two and you can also see the great thing about this here is you can see how different stops of light work so we have here is our here is our point zero and then we have one two three moves but actually in all honesty let's take a it's actually just the number of pictures the differences in light are right here between the images so we have one two three stops of light one two stops of light and three stops of light now honestly if I were taking this photograph and I were just using it if I had a purpose for all this stuff down here if I wanted to make sure that you could see this I would probably if I was choosing an image choose this one right here a lot of times I often underexposed my images and this will be the exposure that I will take for some reason but this is probably this image that I start is probably the the more accurate image for what you would usually be doing in most situations but this just is a great example of how stops of light work and so when when you're taking photographs try to be aware of what kind of difference what kind how much contrast is there between these different points of light and what ways can I measure that and what exposures can I try that will hit them sort of in the middle so here I think this is a pretty nice exposure for this for this kind of light but moving it back one stop is actually pretty good even though it's a little it's a little warm it's a little bit it's a little bit close to overexposing you can see here the book and things like that are are getting really really hot but you know you want to have a little detail here in this image so you might have to say okay well I know by looking at my histogram that this is properly exposed or I metered off of one of these things but I'm going to move it back to here so that I can get a little bit more detail in in this area that has about two stops of light less than this area right here alright so that kind of gives you an idea of what a stop of light is and how it works and what it maybe looks like in an image I hope you enjoyed that and learned a lot and come check out more lessons at alversity.org