What is the meaning of door B in digital SLR camera?

What is gate B in digital SLR camera? Light bulb? It is also an exposure mode, which allows us to control the exposure freely. When a rookie gets a SLR camera, he always looks at the pile on the camera. c、B、M...？ I can't read the subtitles What exactly is gate b? In fact, this is the exposure mode of SLR camera; For micro-cameras or ordinary digital cameras, the buttons of door B will not appear directly on the fuselage. Micro-cameras can enter door B by adjusting the shutter, while digital cameras have no exposure mode at all.

First, the unique B key of SLR camera is the unique exposure mode of SLR camera, which allows the photographer to adjust the aperture at will.

The B key of SLR camera is an exposure mode that photographers are familiar with but not familiar with. After we choose the exposure mode, we can adjust the aperture and shutter speed freely. Although it is similar to shutter mode or even M mode, the biggest advantage is that we can hold the shutter for a long time for exposure! When we feel dim when shooting the scenery, we can press the shutter for a long time in B mode to get our favorite photos. Of course, the camera consumes a lot of power in exposure mode, and the shooting time will be longer.

Second, for ordinary SLR cameras or digital cameras, the significance of door B is actually not great.

Maybe some photographers are wondering why there is no door B in their micro-list. In fact, the B-door shortcut is generally more common in professional SLR cameras, because as a consumer WeChat SLR, there is no independent B-key mode. To enter exposure mode, we need to adjust the shutter in M mode to see it? Light bulb? State; For ordinary digital cameras, unfortunately, due to technical limitations, there is no exposure mode. Digital cameras basically record meetings and have no significance of exposure mode.

It can be seen that door B is the exposure mode of the camera, which is more common in professional SLR cameras.