Application skills of criminal photography technology

Compared with other criminal investigation techniques, criminal photography has strong intuition and convenience, so it has been widely used in criminal investigation. Let me introduce the application skills of criminal photography technology to you.

Application skills of criminal photography technology (1) Make a good choice of shooting methods.

When using criminal photography technology, it is necessary to choose the appropriate shooting method according to the actual situation in order to obtain better shooting effect. For example, in the field shooting, if the blood and traces left on the scene are long, and it is impossible to show the influence with one lens, you can use the method of subsection shooting to show the traces on the scene with several images. However, when using this method, it is necessary to use consistent exposure value to shoot and make the images overlap and cross. Secondly, if it is necessary to observe the shooting effect immediately, so as to provide imaging that meets the needs of the case, the shooting method of adjusting the shooting contrast and correcting the density can also be used [2]. Specifically, it is to reduce the overall contrast according to the requirements of on-site shooting, and use the automatic balance function and exposure gain function to shoot traces of limited on-site environment. After the shooting, the computer can be used to compare and adjust the local density of the images, thus providing a basis for criminal investigators to infer the criminal process. In addition, using infrared imaging and ultraviolet imaging technology, hidden traces can also be photographed. Using these two technologies, hidden traces can be directly displayed on the camera display screen. In the process of shooting, the clarity of the trace can be adjusted by replacing the filters with different wavelengths, and the shooting record of the trace can be completed.

Application Skills of Criminal Photography Technology (2) How to Choose the Shooting Angle

If you want to skillfully use criminal photography technology, you must choose a good shooting angle. In the process of shooting at the scene, as soon as the photographer enters the crime scene, he can take a panoramic shot of the scene environment by using the elevation angle, so as to use the surrounding environment to set off and compare the important signs and physical evidence at the scene. At the same time, according to the building number, address, house number and other signs of the site, the photographer can also take close-up photos of multiple groups to make the photos prove each other. When shooting the on-site physical evidence, you can also shoot it from four directions, which can fully show the location and surrounding environment of the physical evidence. In addition to on-site shooting, it is also necessary to choose a good shooting angle when shooting identification. For example, when shooting criminals, we need to shoot criminals from the front and side. At the same time, criminals should be required to take off their glasses, hats and other decorations to make their five senses clearly exposed [3]. When necessary, original photos of criminals should also be taken. In addition, keep the camera lens flush with the criminal's chest.

Application skills of criminal photography technology (3) Actively cooperate with criminal investigation.

When using criminal photography technology, we should actively cooperate with criminal investigation to shoot. For example, if investigators need to extract fingerprints on the spot, they can use iodine vapor, aluminum powder and nitrate solution to process fingerprint traces, and then use equipment with professional macro shooting function to shoot, so that the image information of fingerprint traces can be accurately captured. When taking photos of corpse identification, considering that the face of corpse may be damaged by time or trauma, digital camera can be used for multi-angle shooting. On this basis, the original photos can be modified by forensic photography technology, and the body can be touched up and digitally made up, so as to obtain similar effects as forensic cosmetic surgery. Therefore, the use of this technology will be able to provide greater help for the identification of corpses.