How does Nikon d780 clear the background?

It seems that you need to change a large aperture lens.

1, using a large aperture lens (fixed focus lens):

In order to shoot a blurred background, a lens with a large aperture is the best choice, but generally speaking, a lens with a large aperture will be more expensive, especially a fixed focus lens. For example, 50 pieces 1.2 costs 1 ten thousand yuan, and 50 pieces 1.4 costs 3000 yuan (50MM is the focal length) (1.2 and 1.4 are the most expensive.

2. Use telephoto lens (zoom lens)

In addition to large aperture lenses, telephoto lenses can also have this effect. A telephoto lens can get a blur effect by maximizing the focal length. We often see many photographers shoot models with 70-200 (using the blur effect of telephoto lens).

3. Use aperture priority mode:

Aperture priority mode is suitable for beginners to take blurred photos. Generally speaking, the larger the aperture, the more blurred the photos, such as F 1.8 F2.0, etc. Of course, it has something to do with the lens you are equipped with. The lens will have a value from the maximum aperture to the minimum aperture, so you can adjust the aperture to the maximum.

4. Use full manual mode (M file):

M file is a mode suitable for people who are familiar with photography. M file can set all parameters, including shutter, aperture, ISO, etc. With M-files, you can get the photos with the most accurate exposure and the most suitable for your taste.

5. Focus on the theme:

In order to take blurred photos, the focus is very important. For example, when we shoot a model, the model is standing in the middle of the flower. Be sure to focus on the model's face, preferably her eyes. After the aperture is opened, there will be less places to focus clearly, except that the model's face is clear, the surroundings will become blurred and the background will be blurred.