How does M3 Canon shoot background blur?

M3 Canon shooting background blur method is as follows:

1, with a large aperture. Set the camera to AV and set the aperture to the maximum. With other parameters unchanged, the larger the aperture, the better the blur effect.

2. Use a large focal length. The focal length can be simply understood as the number on the side of the lens. The larger the number, the greater the focal length, which can be changed by rotating the lens. With other parameters unchanged, the larger the focal length, the better the blur effect.

3. The distance between the characters and the background will also affect the blur effect. Other things being equal, the farther the distance between the character and the background, the better the blurring effect of the background.