What are the skills to blur the background of telephoto lens?

1. The topic should not be too big. It is best to blur the flowers in both telephoto and wide angle. However, it is difficult to take portraits, and it is basically impossible to blur the background when taking full-length portraits of adults. Therefore, if you want to blur, you'd better take a bust, or just take a close-up of your face. It is ok to take a bust of a child.

2. The subject should be as far away from the background as possible. The background is too close to the subject to be blurred. My experience is that if you take a bust, the background should be more than 5 meters away from the main body, preferably 10 meters away. If it is less than 5 meters, it is basically impossible to blur. If you shoot flowers, the background can be blurred about 10 cm.

3. The light-dark ratio between the subject and the background should be as large as possible, that is, try to choose a dark background, so as to achieve the effect of highlighting the subject.

4. The light should be as strong as possible and the shutter should be enough. Hand shaking will affect the focus at macro, and it will also affect the focus at telephoto.

5. The telephoto is not the most important factor to determine the depth of field. The most important factor is the size of the imaging subject or the size of the object distance. The bigger the subject is imaged, that is, the closer the object distance is, the better the blur is. So S3/S5 has better ability to control the depth of field at the macro end than at the telephoto end. However, portraits can only be shot at the telephoto end. At the same time, due to the perspective, the background blur effect of telephoto shooting will be more in line with people's visual habits.