What is the principle of taking X-rays? Why the higher the density, the whiter it is? The negative was originally white. Did it turn black after X-ray exposure? Seek a detailed explanation?

Upstairs is bullshit! X-ray imaging is not reflective imaging, so there is no theory that bones are dense and reflective, so they are white. This is the principle of ultrasonic imaging.

So why is the greater the X-ray density, the brighter the gray scale? In fact, it is very similar to traditional film cameras, which are all caused by film. In the past, the camera used film, and you will find that on the negative, black hair looks white, while brighter skin is black. After the film is developed, it is the opposite.

X-rays and CT films are also imaged with film. When X-rays irradiate dense tissues, such as bones and muscles, X-rays are attenuated greatly, that is, a large number of X-rays are absorbed, so there are fewer X-rays on the film behind the human body, while low-density tissues, such as fat and chest, attenuate X-rays less, and a large number of X-rays penetrate the human body and enter the film, exposing the film.

Film exposure is a process in which silver halide on film becomes silver particles through chemical action. The smaller the density of exposed tissue, the more silver particles are produced and the darker the color (silver particles are black, not white! ! ), and the film after dense tissues such as bones is less exposed, so it is white!