Friends who can SLR help to answer it.

This is called light painting in photography. The effect in the picture is very introductory and easy to do. There are also many advanced tutorials on the Internet.

1. Set the camera mode to m (manual) and set the shutter to 10S or above.

Secondly, enter the setting menu and set the flash synchronization to Hou Lian synchronization.

Third, find a dark place.

Fourth, prepare flashlights, mobile phones, light sticks and other luminous items. The other person draws a shape in front of the camera with a lamp.

5. Pop up the flash, focus and press the shutter.

You can try to adjust the shutter, aperture and ISO several times to make the drawn lines change. It is best to draw the shape in advance to avoid scribbling after pressing the shutter.