“…The mechanical table body is mainly composed of semi-circular camera arm, semicircular light source arm, stage, rotary guide rail, camera trolley, light source trolley, rotary trolley, light source, bracket and darkroom cover. The darkroom hood is composed of a folding frame and a light-absorbing curtain, which can effectively reduce the influence of other stray light on the experiment [27][28][29]; The camera arm is used to support the camera -60˚~+60˚pitch movement, the light source arm is used to support the light source -60˚~+60˚pitch movement, and the rotary guide rail is mainly used to support the 360˚rotation movement of the camera and light source. The stage is used to carry the experimental sample, which can be adjusted in three dimensions in space, and the hollowing is so that there is a certain space below for This structural scheme follows the principles of light structure, convenient transportation, accurate positioning, stable movement and simple structure to carry out the design, the camera is easy to disassemble and assemble, so that the position accuracy of light source rotation, light source pitch and camera pitch can be guaranteed, and the finished product is shown in Fig 6.…”