What does door B of the camera mean?

1. The so-called light bulb, also known as manual shutter, means that when the shutter is pressed, the shutter opens to start exposure, and when the shutter is released, the shutter stops exposure. In other words, the exposure time of door B is determined by the length of the shutter pressing time, and it can be controlled freely without setting the exposure time. This is the role of door B.

2. The name of door B is taken from the English word "bulb", which comes from the rubber ball squeezed by the photographer when he opened the shutter in the old photo studio. This rubber ball shutter release device is still in use today and can still be seen on cameras in many modern photo studios.

3. At present, many digital cameras on the market have B doors, and only a few small portable digital cameras don't have B doors.

4. Set the camera to full manual mode, that is, M-range; Set the shutter to the lowest until the shutter value becomes a "light bulb", which means that the "B door" has been opened. If there is no light bulb mode, your camera has no B door. You can also look directly at the knob at the top of the camera to see if there is a B sign. If there is no door B, there is no door B.

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How to use door b:

Fix the camera with a tripod. Then turn the camera to gate B. Some cameras have a separate B-door mode in the mode dial, and some cameras adjust the shutter speed to B-door after 30 seconds in M-file.

Use a smaller aperture after turning to door B. At this time, it is best to use the cable release to operate the camera shutter, otherwise the shutter button will be pressed all the time. Even if you ignore the camera shake, your hands will be sore if you press it for a long time. Press the shutter button on the shutter line to lock the shutter.

Then wait two or three minutes for a short time and half an hour for a long time to see the brightness of the ambient light. So it is necessary to take more photos. When you feel that the exposure is almost complete, you can unlock the shutter button and the exposure is complete. When shooting, press the shutter and the camera will start to expose until the shutter button is released.

References:

Baidu encyclopedia. B men