Depth of Field Pt. 2

What is the circle of confusion? How does this affect what the viewer of the image perceives overall? How does the camera's sensor come into play with the circle of confusion?  Why?

    The circle of confusion is the leeway for the point of focus as it is difficult to get something perfectly in focus. Looking at it more technically, when a point of light reflecting into the sensor, it forms a single spot of light if it's in focus; however, the further from the point that the subject is, the bigger that spot of light gets, making the image more and more blurry. The circle of confusion is how big that spot of light can get before it affects the image. This affects what the viewer perceives as the bigger the spot of light, the blurrier the image. The camera's sensor comes into play regarding the circle of confusion through the size of the sensor. This is because the smaller the sensor, the shallower the depth of field will be, meaning that the circle of confusion will be smaller and there will be less leeway for the image to be in focus.