To the naked eye, the light bulb is on at night and the background is black. Why does the camera blur without borders when it takes a picture?

The first one is that the flash is not turned on, and the person is black: when shooting at night, if the portrait appears black, it means that the camera does not have enough light. At this time, you can use a large aperture to increase the amount of light, and the ISO sensitivity should be set higher, so as to find the balance between brightness and noise.

As for the shutter speed, you can try to slow it down. If your camera is not anti-shake, you can try1100s. If the camera has five-axis anti-shake, you can try 1/30s.

The second is to turn on the flash and the background is black. The reason for this is that the lighting range of the flash is relatively small, generally only illuminating the main body, and the flash is very fast and cannot illuminate the background for a while. Remember this formula when shooting night scenes: the flash controls the brightness of the subject, and the shutter speed controls the brightness of the background.

So how can we turn on the flash to ensure a bright background? It's very simple. Use a tripod, turn on the flash, and then slow down the shutter speed to about 2 seconds. The background of the photos taken at this time is also bright. Of course, you can also use some natural auxiliary light, such as the light from street lamps and the light in the window of shopping malls. This will be more conducive to your taking clear portrait photos at night.