Electroretinography (synonym of xeroradiography) - method radiography, based on dry (or physical) method of photography. In this method, the receiver of x-ray radiation is not x-ray film, and a thin layer of seleniumprinted on aluminium or brass plate which is placed in the cartridge. In this state, selenium plate is not sensitive to x-rays. Electroretinogram characterized by high contrast and sharpness that enables better than conventional x-ray, to reveal the structure of the bone, and even the soft tissues (Fig. ); it can be obtained for 2 minutes; there is no need to darken; one selenium plate can be used up to 1000 times.

Electroretinogram (1) and x-rays (2) of the knee joint.

Currently, electroretinography applies not only for the study of bones and soft tissue of the limbs, but also for the study of internal organs. High contrast image enables you electroretinography large bones and internal organs without screening of the lattice. Shutter speed only slightly exceeds restraint in conventional radiography.
The disadvantages of the method of electroretinography include a relatively rapid decrease electrostatic potential selenium plates after charging. Therefore, the time between charging plates and its exposure should not exceed 15 minutes, otherwise the quality of electroretinogram greatly reduced.