Hello, it is back to basics time right now at Camera Lessons Online and today we're going to be talking about ISO and how it affects shutter speed and motion blur and image quality. Let's get into it. So right now is Back to School season. I thought that was a perfect time for us to do some back to basics videos here at Camera Lessons Online. Where we're going to explore the exposure triangle, the working pieces of photography and eventually a video on how to shoot literally anything. As always, everything we do here is brought to you by the website Camera Lessons Online where what we believe is very simple that anybody can create powerful visual imagery and to make those skills accessible to everybody. That's why we do the videos here. We've got the website. We have an introduction to photography class. It's about four hours long and we've got a couple books. I encourage you to go and check it out. Anyway, today we're talking about ISO or as it is also referred to simply ISO. In case you wanted to know this stands for the international organization of standardization. The word order is changed because it's translated from French. And what we're talking about is sensitivity to light. There's a device inside of your camera that's your imaging sensor and it is what's going to actually record light and make a picture out of it. So we have to have some kind of a sensitivity understanding of this sensor to the light that it records. So let's imagine you have a camera, a certain sensitivity and you're shooting a picture of a room with 500 candles in it. This is a blatant fire hazard, but just stick with me for a moment. We have some sensitivity in the camera and a proper exposure and 500 candles. If I blow out half of them, 250 candles remain. And now to make the exact same exposure in the camera, I need to be twice as sensitive to light. So I might double my sensitivity. If I blow out half the candles again, I'm down to 125 and I have to double my sensitivity to light yet again. And this is the way that we start numbering and working with the sensitivity to light in your camera. We start at a base or a native ISO. This is usually 100 and then we boost the signal from there and create more sensitivity essentially out of thin air. And that allows us to adapt to different environments, which does mean that ISO helps us control the brightness of our photographs. However, one thing that's really important to keep in mind is that this is going to have image quality consequences. And it's going to do so because of something that I just briefly referenced. And that is something we call the native ISO of the camera. That's the actual sensitivity to light of the sensor itself. For most cameras, this is 100 ISO, but there are some there lower 64 ISO and the Nikon D850 as an example. And some of them that are actually a little bit higher. There are several Lymphos and Panasonic cameras that have 200 ISO as the native ISO of the sensor. So this is an actual mechanical thing with the sensor itself. Every ISO that we choose above that, for instance 200, 400 or 800, which are ever increasing amounts of sensitivity, we create those by boosting the signal of the sensor itself. Now when you boost the signal coming from the sensor, you generate noise. This is actually a degradation of your image quality. Sometimes we'll call it digital grain, digital noise or just noise. And all of these are going to be degrading the image quality as you increase your sensitivity to light. Now why would we actually do that? You increase your sensitivity to light to essentially make up light that's not there, which allows you to shoot at faster shutter speeds. So I want to show you an example of that. Here's some boring pictures. They're going to be just a couch in my workspace. But I'm going to show you the ISO that I shot at and the corresponding shutter speed that provided the same exposure. As you can see, as I increase the ISO, in order to make sure that the picture does not change brightness, I have to choose ever faster shutter speeds. And this means that ISO grants me the ability to shoot at faster shutter speeds, even in darker environments. And my trade off for getting faster shutter speeds in environments that normally would not call for them is going to be a loss of image quality. And as a result, I like to say that your ISO is actually a crutch for your shutter speed. It props up the shutter speed that you really want to achieve. And it does so artificially by basically inventing light that doesn't exist off of the sensor, which really is effectively just changing your sensitivity to the actual light in an environment. Now, a lot of people think about ISO in a way that is actually incorrect. They think that ISO is something we change depending on the amount of available light. And indeed, if you shoot in brighter environments, you're typically shooting at lower ISO values. And as you shoot in darker environments, you're typically shooting at higher ISO values. But what's key here is that that's not the way we actually made the ISO decision. So right now I want to show you a picture of the Millennium Bridge here in Denver, Colorado. And this is of course a nighttime shot, but I did it at 100 ISO. I did that because I was shooting it on a tripod. Now, of course, you're going to say, well, that makes total sense. You shot it on a tripod. So of course, you don't need a higher ISO. But think about what we just did. We just disconnected the ideas of available light and the ISO you shoot at. They're related topics, but they're not directly connected to each other. Instead, we make ISO decisions based on the possibility of blur in our photography. If there's a higher likelihood of blur, we tend to shoot at higher ISOs in order to achieve faster shutter speeds. Now, it's important to keep in mind here is that there are actually two types of blur in photography. This is not something I mentioned in the shutter speed video, because I think it's good to introduce in an ISO topic. But there are two types of blur in photography. The first is going to be camera blur. This is where the movement of the camera shows up as blur in the image. The second type of blur is going to be subject motion blur. And this is where the movement of a subject shows up as blur within the image. Now, these can be corrected in different ways. If I have camera motion blur, then I can effectively lower the movement of the camera either through stabilization in a lens or camera body or on a tripod. Or I can shoot at a faster shutter speed. But if I have subject motion blur, the only way to solve that problem is going to be by shooting at faster shutter speeds. This is why tripods and stabilization do not help you when you're working with fast moving subjects and subject blur. It's just not an effective way of actually tackling that problem. However, shutter speed can be used to solve any type of blur in an image that you might have either from subject or from camera. As a result, it's an easy thing to go to. As we see more likelihood of blur within a frame, either from camera or from subject, increasing the ISO gives us the ability to choose a faster shutter speed and thus solve the problem. However, if you're likely to be shooting in an environment with camera blur and not subject blur, such as night scenes or a nice long sunrise landscape photograph, then you're better off shooting on a tripod and lowering your ISO in order to get the better image quality. Insumption ISO is going to be essential to being able to actually adapt to an environment that you're working in. We increase the ISO only if we need to achieve a faster shutter speed in order to be able to accommodate for motion and blur within the frame. If you have less possibility of blur, then you're going to be able to lower the ISO. And for this reason, ISO is inexorably linked to your shutter speed decisions, which is why I put the two videos back to back. Next time, we're going to be dealing with the third part of the exposure triangle, which is going to be your aperture. Thank you so much for taking your time to join me. If this was useful, of course I'm going to ask you to like and subscribe. It's free. And thank you for taking your time, and I'll see you next time. Bye.