One of the film stunt photography methods uses infrared rays as a light source, and the photosensitive film used is sensitized by a cyanine dye that absorbs infrared wavelengths. The infrared spectrum used for photography is in the range of 700 to 1300 nm. When shooting, add dark red to the front of the lens.
The black color filter filters out ultraviolet rays and visible light in sunlight, or irradiates the subject with an infrared light source. The photosensitive film is exposed to only infrared rays and a small amount of red light, and then subjected to general development processing to obtain a positive film. Because infrared rays can penetrate soot and mist, you can get a clear image in distant and high-altitude photography. TV is used to simulate night scenes in daylight.
According to tests, infrared rays can reach more than 40% in natural light radiation. In black and white photography, visible light can be blocked from red to dark red to dark red by using special filters, so that infrared images are sensitive on the film. For example, the “Ryden 87C” filter can block all visible light to produce a purer infrared photographic effect. This filter is almost opaque to the naked eye. In the specific operation, the focus should be adjusted before adding the filter. Take a shot to get the normal amount of exposure. In general, infrared photography can be used with the "Ryden 25" red mirror, which can also produce a more obvious infrared effect. So what are the reasons for infrared photography? Analysis of the brightest objects seen by the human eye, such as the blue water surface and the sky, they can not reflect more infrared light, so although the imaging of ordinary black and white film is normal, the infrared film shows a darker color. Trees and grasslands can turn white because of the large amount of chlorophyll that reflects infrared rays, in order to achieve a more realistic concept. Infrared not only provides a special creative method for photography, but also because of its high transmittance, it can also be photographed in the face of fog and smoke, and is often used for exploration and military reconnaissance in scientific research. The use of infrared rays has the characteristics of penetrating the surface of the picture into the interior of the paint, and it can also judge the authenticity of the famous paintings of the masters.
