Excuse me, what do these keys mean? When can I use it?

1 Electronic dial has different functions in different modes, such as adjusting aperture, shutter speed, focusing point, etc.

The hot shoe is a mechanical switch contact, which is used to trigger the external flash synchronously, thus ensuring the synchronization of the camera shutter and flash. The "hot shoes" are arranged in the middle of the socket of the external flash of the camera. There are also corresponding contacts on the pins of the flash lamp that can be triggered by "hot shoes".

13 When removing the lens, press the lens release ring, and the lens can be removed by rotation.

The second picture

2 Automatic exposure lock The automatic exposure lock key is used to lock the exposure value of your photometric part, and it will not affect exposure value whether it is re-composed or not.

Adjust the dial of 5 diopters, such as myopia and hyperopia. Adjusting diopter can make users see more clearly in the viewfinder.

9 The exposure compensation dial is to add some buttons on the basis of the current exposure. For example, under the backlight, the subject is unclear and the light is weak, and the automatic exposure of the camera can't meet our requirements, so exposure compensation is used. The camera will increase or decrease the aperture and shutter according to the compensation amount.

12 The remote control terminal is connected to the terminal of the remote controller, and automatic shooting can be performed after the remote controller is connected.

16 metering button metering switch button, which can be adjusted to average metering, center metering and face recognition metering.