In this article we will analyze the meanings of the following words: focus and autofocus.
To begin with, let’s do this experiment: pick up a small object in front of you, such as a pencil, at eye level, at a distance of about 15-20 centimeters from the face and look at it. You see it absolutely clearly and can see every smallest detail or inscription on it. Now the pencil is in focus of your eyes, which, like the camera lens, are an optical device.
Note that the background, that is, all the objects behind the pencil, appear in a blurry, fuzzy state (and the farther after the pencil they are, the more fuzzy they are perceived while you look at the pencil).
Now look behind the pencil, leaving it on the line of sight, and look at the objects in the distance. While you look into the distance, that is, you focus your eyes on objects in the distance, the pencil is not clearly visible to you, it remains blurry, but if you look back, the picture changes exactly the opposite.
And that’s when the object is clearly visible, without blurring, they say that the object is in focus, that is, the focus is on the object. Or you can hear the expression: bring sharpness. This means the same thing as focusing on the object, making it clear on the image.
For the purity of the experiment, you can repeat it by closing one eye, it will save you from a split image.
Focusing on the camera, depending on the model and your settings, is done either automatically (autofocus), when you press the shutter button, or manually, by rotating the ring on the lens.