This video is a video about the basics of digital cameras. In fact, it is true that the technical know-how of video shooting has become meaningless these days. The reason why the video shooting method is difficult to explain is because of the development of smartphones. It's time to just take out your phone from your pocket and shoot a video. But creators who value video beauty still buy and use expensive cameras like this. The reason is simple. The depth of field and the texture of the video that smartphones cannot realize. I think the reason why people buy cameras is exactly these two reasons. There is Auto mode that can be used by pressing the shooting button without any special settings, such as auto mode like a smartphone, but if you want to use auto mode, It is recommended to use a cell phone rather than a camera. Anyway, for that reason, if we want to use the camera properly, we need to have a clear understanding of exposure. First, exposure is brightness. For example, if you want to take a bright picture, you can take a bright picture, but this is usually called overexposure. If you want to take a dark picture, you can say that this is exposure under. It's possible to guess from here, but having over and under means that there is a certain standard, and we call that standard a fixed exposure. And on the camera, the fixed exposure is usually marked as 0.0 or 0.00 in a mechanical way. Exposure is determined by the three factors of shutter speed, ISO, and aperture, and the exposure is fixed exposure as a combination of these, and it can be over or under. The aperture, shutter speed, and ISO have their own functions, but each function is connected organically, so if one side works, the other side is also affected. Like a double-sided tape. This is the core of exposure and the most basic basis. Now, we have to understand this part clearly and start now. Let's go into the aperture first. The aperture is the hole in the lens. In fact, it's not a hole, it's a structure that's like a blade because several horses are interlocked. It looks like a hole. What is the concept of observation? When you look at something with your eyes, the reflected light comes into our eyes. Then the camera also needs light to distinguish objects. Humans accept and interpret the reflected light by our brains, but the camera is not the brain, but the sensor. It's an image sensor that you see now. The aperture is a hole that controls how much light will come in. The bigger the hole, the more light it receives, and the smaller the hole, the less light it receives. I said that the exposure is determined by the three factors of the aperture, shutter speed, and ISO. Then let's make a guess. When the shutter speed and ISO values are the same, the aperture is likely to be overexposed because it absorbs as much light as the aperture opens wide. On the other hand, if you set the aperture hole very small, the light will come in relatively little, so it is unlikely to be overexposed. The important thing is how wide the aperture is. How do we know this? It is common to be measured by the f-value of the camera. As you can see now, the number f is marked at the bottom. That's the value that shows whether the aperture hole is large or small. The aperture can be said that the lower the f-value, the larger the aperture hole is, and the higher the f-value, the smaller the aperture hole is. For example, with a Sony camera, you can see that the aperture value changes when you turn the dial, but when it goes down to f1.8, the aperture hole is open to the maximum, and when it goes up to f11, the aperture hole is narrowed. And the aperture has another function other than accepting a lot of light. It's called out-focusing. If you want to take a shot that feels like an expert took a picture, if the background is crushed and blown away, it feels like an expert took a picture. The reason why this is the case is because it's a scene that's hard to see in the real world. It's not that you can't see it. It's just hard. It's because it's a scene like that. It feels prettier. It's actually very simple to blow the background like this. You can open the aperture. This is called the depth of field. The more you open the aperture, the more the background is blown away. And in other words, the depth of field is low, and the aperture is closed, so the background is almost gone. This is called the depth of field. Why is it deep? You can understand it like this. Why do I say it's shallow and deep? If the water is shallow, it will only wet a part of my body. On the other hand, if the water is very deep, the whole body will be wet with water. So the deep one is all focused. And the shallow one is very focused. Now, we've learned two functions of the aperture. First, you can adjust the amount of light you receive. You can blow the background. Now, you might think that it's better to open the aperture a lot, but that's not true. Because if you open the aperture, the exposure is over, so the image is very likely to be blown away. So you need to understand the next concept, shutter speed. For example, you want to go to your friend's house. I pressed the shutter of the apartment front door. And my friend slightly opened the front door. I'm telling you this. I'm going to open and close the door for a very short time, for 1/30 second. You come in quickly in the meantime. It doesn't make sense. If it's 1/30second, I'll put a finger in here. Anyway, I don't know why. The door opens and closes for a short time. 1/30 second is the shutter speed. No matter how much I open the aperture, I send it in a hurry to see the light. If you don't open the front door, the light can't be passed through the sensor. To be precise, the front door is the sensor's opening time. For example, in the past, DSLRs had mirrors like this. If the lens is in front of you, there's a mirror here. And when you take a picture, the lens opens and the light comes in. The mirror will go up and down in an instant. So if you take a picture with a DSLR, it makes a click sound. The sound of the mirror going up and down. On the other hand, mirrorless means there's no such thing as less. So there's no mirror. It's 100% a mirror. Wow, this is a real mirror. Anyway, the shutter speed is the time when the mirror opens and closes. When the mirror opens, the light comes in. If it closes, it can't come in anymore. It's blocked. So, even if you opened the aperture hard, If the mirror doesn't open, the light can't pass. You can think of it like this. Mirrorless. So, the shutter speed is open and closed. You can say that. When you physically observe it, it looks like that. In fact, when you look at the structure of the sensor, You can see that the surface opens and closes according to the shutter speed. If you set the shutter speed to 1 second and take a picture, Literally, the front door opens for 1 second. And in fact, 1 second is a very long time for the camera. Usually 1/60, 1/1000, even 1/4000. It's going to open and close for a very short time. The time set by the shutter speed is the shutter speed used to take a picture. For example, if you set the shutter speed to 1 second, Then, by opening and closing for 1 second, It creates an image of a picture. But on the other hand, if you set the shutter speed to 1/60, A picture is completed in a very short time. One image is completed in 1/60 seconds. In other words, you can take 60 pictures in 1 second. And this is called a 60-frame video. In other words, the shutter speed is related to the frame of the video. For example, if it's 24 frames, 24 images in 1 second are passed through. 30 frames are 30 images in 1 second. Then I'm curious about something else. Can we set 30 frames and set the shutter speed to a slower speed than 1/30 seconds? It's impossible. As I said before, 30 frames is a picture of 30 images in 1 second. In order to do that, you have to take more than 30 pictures in 1 second. But slower than 1/30 seconds. For example, if you set the shutter speed to 1 second, You can only take one picture in 1 second. You have to set it to 1/30 seconds, but the shutter is open and closed at that speed. Because it repeats this, You can take 30 pictures in 1 second. If you go below that, it doesn't fit the calculation. Anyway, back to the concept of exposure. Exposure is a shutter that takes enough light first, I took a short picture of it as a shutter speed, I told you it was an image. So, to get the exposure I want, You have to consider how much you're going to open the aperture of the shutter. Second, you have to consider how long you're going to open and close the shutter speed. If I opened the aperture wide for out-focusing, Then a lot of light will come in. But in that situation, if you set the shutter speed very slowly, There is a high chance that the exposure will be over. There's too much light coming in during the time the mirror is open. So if you open the aperture a lot, On the contrary, you have to set the shutter speed a little short to get the right exposure. But on the contrary, I don't like out-focusing. I thought it would be nice if the focus was evenly on all screens, so I tightened the aperture a lot. Then, the light that passes in the first place will come in very little. But in that situation, if you set the shutter speed very short, only this much light will come in. Then the image gets dark. There is a high possibility that it will be exposed. So, if you tighten the aperture, on the contrary, you have to open the shutter speed a little longer. If you open the door for a long time, even if the light that comes in in the first place is small, the light will come in properly in the end. Now, if you understand the aperture and shutter speed like this, it is not an exaggeration to say that we have learned a lot about exposure. In fact, when I shoot, I opened the aperture as much as I could, and I did the shutter speed as long as I could, but there are definitely situations where there is not enough exposure. In this case, there is nothing we can do. You have to use the light that has already come in. What you need at that time is ISO. You can think of ISO as the last bar. Because it is used when the limit of the amount of light that can be accepted is clear. Even though I opened both the aperture and shutter speed, the light is still not enough. For example, in the case of this room, it is a little bright because the lights are on, but the environment called room is a very dark environment than we think. ISO is also called the sensitivity of light in professional terms, which literally means how sensitively you will handle the light that comes in. So, ISO is the minimum light that can be the most efficient. The situation of raising the ISO directly is very clear. When there is not enough exposure, that is, when the screen looks dark. But you shouldn't raise the ISO carelessly. Because it is a spark by heating the light that has already come in, there is a heating phenomenon in the image. In other words, noise occurs. ISO 200 and ISO 25600 have a significant difference in noise particles. So, it may be good to raise the ISO as little as possible in terms of quality, but when I usually shoot videos, I set it to 800, 1000, 1200, 1600, and if the exposure is a little insufficient, I raise it to 3200 or 6400. But I never raise it above that. Because the noise in the video gets too bad. When we shoot, we have to raise the ISO inevitably, but in a dark environment, there is little light, so we have to raise it. But I don't recommend raising it too much, like 12,000 or more. So, today I summarized the concept of exposure of the camera as an example. And to tell you a little bit, exposure is not always the best 0.0 exposure. Exposure is literally a standard according to the exposure meter. Usually, when I shoot a video, I usually shoot with +1.3 or +2.0. Because I overexposed. Here's another concept of dynamic range. If you understood the concept of exposure in today's video, you should understand the concept of color next time. I'll explain in detail about color correction, color grading, and dynamic range. If you enjoyed today's video, please press like before you leave. Your likes are a great motivation for the creator to make the next video. So don't forget to press like and leave. Then I'll say goodbye in the next video. Thank you.
