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Current time:0:00Total duration:2:07

Video transcript

in the previous exercise you probably notice that a very small aperture results in a sharper image but it's a dim image because very few light rays are making it through that pinhole and entering the camera we can make the image brighter by expanding our aperture size but there's a trade-off when we do this it results in a blurrier image here's why let's look at our scene again and look at one point in that scene there's light bouncing all around our scene and at that point light rays are going in all directions our pinhole only lets light from one direction through as we make it bigger it lets more light rays through making the image brighter but this presents a new problem it lets light from our point spread across more of the image plane that tiny point in our scene now covers a big area in our image that's the image blur aside from the size of our aperture there's another important feature of this camera that we can manipulate that's the distance between our image plane and the aperture I'm going to call that distance the focal distance if we move the image plane closer to the aperture the objects in our scene appears smaller but we see more of the scene so we say our field of view widens when we do this if we move the image plane farther away from the aperture the opposite happens now the objects in our scene appear bigger but we don't capture as much of the scene in this case we'd say the field of view is narrower so there's some kind of relationship between the focal distance of the camera and its field of view this is a really important concept so let's pause here in the next exercise you'll have a chance to develop your understanding about what's going on here by playing with a virtual pinhole camera with a variable distance between the aperture in the image plane give it a try