Photography is the measurement method of human body size with the smallest error.

Photography is the measurement method of human body size with the smallest error. (correct)

Daguerre photography is also called "silver photography". It was originally created by Daguerre, a Frenchman. /kloc-0 was published in the world on October 7th, and used around 1839 and 1860. This is the earliest photography method with practical value in the history of photography. This is a direct positive method that appears on silver-plated copper plates and cannot be printed and reproduced. Its basic method is silver plating on polished copper plate.

The surface of silver is smoked with iodine vapor to produce photosensitive silver iodide. Put this photosensitive silver plate in the cassette for later use. When shooting, this kind of silver disk is put into a square box camera with a lens aperture of F3.6, and the exposure time is about 1 minute.

After shooting and exposure, the silver surface was developed by mercury vapor fumigation. In the light-receiving part of the silver plate, mercury and silver form a shiny amalgam, forming a bright part of the image. The unexposed part of the silver plate has no amalgam and still exists in the form of silver iodide. After development, the silver plate was fixed with baking soda solution, and silver iodide dissolved, showing a black copper plate, which constituted the dark part of the image.