What was the name of the dance held by photographers in the studio in the 1950s?

This thing is called pneumatic pay-off, which is used with old large format cameras (some hand-held cameras can also be used). This ball is called blowing balloon, and the rubber tube is connected to the air cavity interface on the camera shutter button. When the balloon is squeezed, the air is compressed and the camera shutter moves.

Professional photography requires high camera stability, and sitting camera can meet this requirement. The release of pneumatic cable can further reduce the vibration caused by knocking the shutter on the machine by hand. At the same time, the use of pneumatic pay-off also facilitates the communication between photographers and customers (making up for the situation that photographers hold the vendor's drums to tease children themselves).

Nowadays, digital SLR or micro-camera has replaced pneumatic cable release with shutter remote control or electronic shutter connection, and its working principle and function are the same.