What is the safety shutter when shooting with a SLR camera? Is the safety shutter absolutely "safe"?

Safety shutter actually refers to the shutter speed to ensure the imaging quality. Just an important reference.

When shooting with a SLR camera, the exposure is determined by the aperture and shutter. When shooting some specific people or still lives, photographers like to use aperture priority to ensure a large aperture to highlight the subject. If the light is insufficient, it will slow down the shutter speed.

Due to the slow shutter speed, the movement traces of photographers and cameras will be recorded, resulting in blurred photos. The critical point of this speed is called the safety shutter (speed). Ordinary hand-held shooting is generally limited to115s, and a faster safety shutter is needed when zooming in or out.

The safety shutter is not mechanically set on the camera, it is just a reference data for the photographer to judge. Safety shutter is not a rigid iron law. It is very important to adjust the photographer's posture and breathing. Relying on shooting or getting on a tripod will improve the success rate of photos.

However, if we continue to slow down the shutter speed, we will face that the irregular motion of the subject will also be recorded, so photographers need to use lighting, narrow the aperture and even improve the sensitivity (iso) setting to solve this problem.