How to use the flash of SLR?

1. Generally speaking, flash synchronization can be divided into automatic and fixed. In automatic mode, the shutter speed will be adjusted according to the aperture. When it is fixed, such as your 1/200 seconds, the shutter is fixed.

2. After selecting a fixed flash synchronization time, the shutter speed is fixed. For example, yours is 1/200 seconds.

3, the choice of aperture is not indifferent, because the aperture can also control the depth of field. The fixed flash is synchronous and the shutter is fixed.

4. flash synchronization is the same as built-in flash. You are using fixed flash synchronization now.

Fixed flash synchronization is usually a high-speed flash synchronization of a camera, and its shutter speed is fixed. The amount of light passing through is adjusted by the amount of flash. If the aperture is too small, the index of the flash is not enough, and the subject is far away, the flash can not effectively fill the light. At this time, it is necessary to appropriately increase the aperture, or change a flash with a large index, or get close to the subject, or improve ISO.