Understand ISO: It is not really what you think it is.

1. Introduction to ISO: Good day. My name is Warren Marshall. This course is all about ISO. We're going to teach you how to use ISO. We're gonna teach you what ISO actually is. And we're going to teach you how to improve your photographs with the knowledge that you get from using your ISO in the right way. Now, many of you will know that I'm not a big fan of the exposure triangle. The exposure triangle is a way that a lot of photographers use to describe the three exposure options that we have, ISO, aperture and shutter speed. One of the reasons why I don't like it is because ISO has no bearing on our exposure. I'll explain that to you in a little while. But ISO is supposed to be a measure of the sensitivity of your sensor to the light. It's not actually the case. It's also not a creative option for us as photographers. Not nearly as much as aperture, shutter speed, lens choice, viewpoint composition, all of those things. But ISO is still an important part of what we do. And you're going to learn all about ISO in this class. We're going to cover aperture and shutter speed and some of the other technical side of photography in future courses. So come in, have a look at what our ISO is and the skin will give you a good basic understanding of how to control your camera. 2. What Really is ISO?: Welcome to this class. Now, ISO, as I mentioned before, is said to be a way of controlling the sensitivity of your sensor to the light. It's not really the case. Back in the film days, we used to have film rated at different ratings. We used to have two different rating systems. We had din, DIN and we had ISI. So low DIN or ISA numbers were reasonably low sensitivity the film. And high DIN or ASA numbers, we're very sensitive to film, so we would use those in darker conditions. In 1974, digital photography was in its infancy. The International Organization of standardization was set to change those ASA and DIN writings to one standard that will be worldwide. They came up with the ISO system. Iso roughly standing for the International Organization of standardization. Now, ISO was a very similar system to the other two, in that it rate of the sensitivity of various different films. Low ISO films were reasonably slow or less sensitive. High ISO films were reasonably fast or very sensitive to the light. Now, with digital, with their digital sensors, we can't change the sensitivity of our digital sensor. It is just one base sensitivity. It doesn't change how ISO changes the way our images in our digital cameras is that in post-production, after you've taken the shot, your camera artificially increases the exposure or decreases it depending on the ISO that you have. So if your base ISO is 200, on your digital camera, you take a photograph at 800 ISO. Your camera will in post-production in the processor in the camera, increase the brightness of that photograph by two stops. So it doesn't actually control the exposure of our image on our sensor. All it does is artificially raise the brightness of our photograph to a level that would be equivalent to 800 ISO. Now, this is a fairly complicated process and it's a little bit difficult to think of and to cope with for most digital photographers. So for the moment, we are just going to assume or imagine that the ISO rating of our digital cameras does change the sensitivity of your sensor. Okay, I'll explain to you that it doesn't really, but it makes things easier if we imagine that it does. 3. How to Use ISO: So how do we use ISO and our photographs? Generally speaking, a low ISO of maybe 100 or 200 would be used in situations where we have a lot of light, bright sunlight for instance. So we don't need that extra sensitivity or that extra boost in gain from our ISO. When we're shooting in duller light, then we need a higher ISO rating. So we might use a 1002 thousand. A lot of cameras go up to 64 thousand or more with their ISO. So the camera's boosting that signal quite a bit to achieve the brightness that you would expect from a 64 thousand ISO image. So once again, low ISO, say one hundred, two hundred, will be used in situations where we have a lot of light to work with. We don't need a lot of sensitivity to produce an image at that sort of brightness range. When we're shooting in duller light conditions, maybe predawn or post sunset or in the evenings or in an interior of a room. We might need to boost our ISO up to maybe 500, 1000, 2000, depending on the conditions that we're working in. Now the way that I use ISO is that I don't change it often. I tend to use ISO as my base sitting get to a particular location. So if I'm shooting on the beach on a bright sunny day, I'll arrive there, get my gear yet, and I'll probably set an ISO of 200 or 100 and leave it there for the whole day. I'll only change it if my lighting conditions change. If the sun goes behind the cloud or if the sun goes down, then obviously my environmental light is less. So I need to change my ISO to cope with that. But most of the time during the hour or two hours that I'm shooting, my ISO stays the same. If I'm shooting indoors, if I'm shooting available light indoors, then I might set an ISO of 506, 100, or even 800 and leave it there for the whole time that I'm there. It's not the sort of thing I change often, like my aperture or my shutter speed. I tend to leave it the other sign white, which is another reason why I think that exposure triangle is a little bit misleading because the ISO is pretty much a constant when we're shooting in a particular location. 4. How to select Your ISO: The way you set your ISO and your camera varies between camera makes and models. But it's a fairly basic settings I should be fairly easy to find. Just check your instruction manual and that will tell you how to change your ISO. Now, to start with, if you want to be in control of your camera and you want to be able to set a particular ISO, you'll need to turn off auto ISO. Automatic ISO is often the default setting that a lot of cameras come with out of the box. So you need to turn that off first because if you leave Auto ISO on it, we'll often second guess you and change that ISO away from what you originally set. So you're out of control. I prefer to control my camera and set the settings that I want to set. So I shoot on manual settings, on manual exposure mode dial and turn off my auto ISO. So once your auto ISO is turned off, you can set whatever ISO you like. If you're shooting outdoors, set it to 100 or two hundred and four hundred is a fairly good default for most situations. So set your ISO depending on the conditions that you have. I'll include a little cheat sheet that will show you approximate ISOs to use in various different lighting conditions. And that should get you off to a good start. 5. Noise and other issues: Now you may say, what is the best ISO to use? I've described various different lighting conditions. You can set particular ISOs. But if you are shooting indoors and you've got control of your lighting, that you can boost it up brighter or drop it down lower. You generally better to shoot on the lowest ISO so that you can. Now a lot of photographers say that they always shoot on 100 or 200. Which to me is a little bit strange because sometimes they would be in situations where that's going to be way too low. So my general purpose eyes so is 400, RUs 200 a lot? I use 800 a lot, but generally I'm around that 400 area. Now, one issue that you do need to consider when you are playing with this ISO and using various ISO settings is the secondary consideration of ISO. Now, the secondary consideration of ISO is that it will add more noise to your image as you get higher with your ISO. Now noise is the tiny little grains of color that make up your picture. When you zoom in very close to a photograph, you'll see that it's made up of tiny little grains of color. Now, that granular look tends to be more obvious as you go up higher with your ISO. Now again, a lot of photographers really freak out about images with a little bit of noise in them. That's why they locked to shoot at lower ISOs all the time. I would much rather shoot at whatever ISO suits my conditions, then have to try and struggle to get my other settings to compensate for my low ISO. So I regularly shoot at high ISOs, 1, 0, 0, 0, 0, 5000 sometimes. Because if the lighting conditions are so that I need that high ISO to create an image, then I'll do that. Have looked at some of these images that are created on high ISO 1, 0, 0, 0, 0, 5000. They do have a little bit of grain in, a little bit of noise in them, but I think it adds to the feeling of the image. I loved some of these images because they look so ether all and so beautiful. So embrace that grain. Sometimes it's great to shoot with that sort of noise in your image because it gives you a different feeling in your image. Obviously, if you have the choice and you've got plenty of light around, you're better off to shoot at lower ISO because the quality of your image will be that much better. There are a couple of other things that increasing your ISO will affect in your image. The first one is the dynamic range. Dynamic range is the amount of tones that your image can capture from blacks to watts. When you're shooting at your base ISO, which is 100 or 200, your camera will be able to record its normal dynamic range from black to white as you go up higher with your ISO, once you get to reasonably high ISOs, it starts to reduce that dynamic range. So you might find that your shadows aren't quite as visible or your highlights might not show up quite as well. Now, this really is a very minor consideration, but it's there nevertheless. So you need to consider that. One other thing that really high ISOs can do too, is to meet your colors a little bit. Your colors don't look as brought in those higher ISO images. So think about that. If you're shooting an image that doesn't rely on that bright color to produce it, then it's not a major problem. But these are other effects that you're high ISO can have on your image. Okay. 6. Priorities: So even though ISO is important, it's fairly low on my priority scale. When I'm thinking about the most important parts of my image. If I need to go up to a 1002 thousand ISO, I'm fine to do it. But if I can shoot at 100 or 200 and fine to do it as well. But I wanna make my life easier. And I want all of the other more important things in my image to take priority. So my overall exposure, my focus, my colors in my image when I'm shooting people, the pose, the expression, the lighting, all of those things take higher consideration there. My ISO. Now I shoot most of my stuff outdoors with flash. When I'm using flash, I have the big advantage of being able to control have brought the lot is on my subject. But my ISO still matters to a certain degree because my background is there. My background has a certain amount of ambient light on it. So if I want that background to be exposed the way I wanted exposed on need to control my ISO in that situation. So exactly the same situation would occur if I was shooting available lot. I would just set my ISO to a particular range depending on the light in the environment and how bright it is to get my background right. And then I can just alter the power of my flash and my other camera settings to control a lot on my people. I'm using constant light such as LEDs or something like that, which I don't do very often, then I still need to be conscious of my ISO because LED lighting or any sort of constant loading tends not to be as bright as flash. So I tend to use higher ISOs for those sort of shots as well. A lot of LA days time putting out very much light at all. Particularly if you're shooting in the middle of the day or in daylight hours, you need to have them very close to be able to have an effect on your subject. They will get better in the future. But at the moment, diode very dull and they don't have anywhere near the amount of power that even a small cheap flesh unit will have. 7. Your Project: Your project for this class is to produce two photographs. One at low ISO, so 100 or 200 ISO. And the other one at a much higher ISO, say one hundred, ten hundred to 5 thousand ISO. You'll need to adjust your other settings depending on the lighting conditions at the time, you might need to make the shutter speed faster or your aperture smaller when you're using those high ISOs so that you don't blow out your exposure. So do those two shots, upload them into our project section and give us a few words about the differences between the two. Maybe which one you like the best, how easy your founded shooting at higher ISOs, anything like that. That's going to help us and help our students to understand more about this topic. 8. Wrap up: So that's the end of this course. Iso is an important thing in our photography. Astronauts. We need to know about ISO and we need to know how to use it. But it tends, as I said, not to be quite as creative with some of the other options that we have available in our camera settings and AR camera controls. But an understanding of why. So we'll give you a good idea of how bright your image is going to be. So if you can try different ISOs, try shooting a different ISOs and see how you feel. Don't take my word for it. You are an individual. You know what you're doing, work out what's best for you. I always tell people not to believe anything that people tell you until you try it out and experiment with it and see the results that you get. You might find that you like different ideas than, than I do. So try that, see hey ago and I'll see you in the next class.