With slow shutter speed, it's more likely that you or your subject is going to move while the shutter is open, causing motion blur in your photo.

如果快门速度较慢，则快门打开时，您或您的拍摄对象很可能会移动，从而导致照片出现运动模糊。

youdao

With a slow shutter speed it's more likely that you or your subject is going to move while the shutter is open, causing motion blur in your photo.

但是这里一样有个缺点，那就是使用慢速快门时，如果你或者你的被摄主题有任何移动的话，你的照片中就会出现动态的模糊。

youdao

So now you know what "dragging the shutter" means... you have dragged it down to slow speed shooting.

现在你明白拖动快门是什么意思了吧，拖着快门放慢速度。

youdao