The role of filters How to use filters better?

The following are some common filters and how to use them. 1, color temperature conversion filter When the color temperature of the irradiated light does not match the color temperature of the color film, it is necessary to use a color temperature conversion filter to convert the color temperature of the irradiated light into a color temperature consistent with the color film. There are two kinds of color temperature conversion filters: one is the blue color used for sunlight shooting, such as Leiden 80 series. The other is amber, which is used for sequins in the sun, such as Leiden 85 series. 2. When a polarizer is used in color photography, the reflection on the surface of an object will often reduce the color saturation of the photo, such as shooting water features, glass walls, the sky and other nonmetallic surfaces. The use of polarizer can eliminate reflection without affecting the phase of the subject. Polarizers can also control the brightness of the sky and balance the contrast between blue sky and white clouds, blue sky and buildings. When in use, it should be rotated to select a suitable position. The light blocking rate of polarizer is relatively high, and the factor is 2.5-4, so the exposure should be increased accordingly when shooting. The polarizer on the left eliminates the reflection of water to a certain extent, which makes the background of lotus darker and highlights the main body. There is no polarizer on the right, and the over-bright water surface reflects light, which affects the performance of the main body of the lotus. 3. Color temperature balance filter The function of this filter is to slightly correct the color temperature of the irradiated light and absorb too much red or blue light in the light. For example, in the early morning or evening, the color temperature of sunlight is low and reddish, while in cloudy days or under the shade of trees, the color temperature of sunlight is high and bluish purple. 4, UV mirror UV mirror, also known as ultraviolet mirror, transparent. Using this mirror when shooting open vistas in high mountains, seaside and other places can filter out ultraviolet rays, reduce blue-purple light waves transmitted to the film, make the vistas clear, improve the contrast and color saturation of distant vistas, and make the colors more realistic. In addition, this kind of filter can often be installed on the lens and used as a lens protector. 5.Sky lens This is a light red filter, which can absorb the light equivalent to the green spectrum of the negative in illumination. Shooting color film in clear sky, using this mirror can reduce the blue tone, which is beneficial to color reproduction and can keep the skin color of the characters true and natural. Sky mirror 6, half-color mirror, two-color mirror and three-color mirror all belong to special effect filters. If used properly in color photography, photos can produce special artistic effects. Semi-transparent and semi-reflective mirrors, dichroic mirrors and trichromatic mirrors are composed of colored colloidal filters sandwiched between two pieces of optical glass. There are various color combinations, which can produce various special color-changing effects. When using this kind of lens, the lens is mounted on a rotatable frame to increase the diversity of color changes. 7. Cross mirror, snowflake mirror and miter mirror. In some artistic photography and advertising photography works, the light source or reflected light point presents dazzling light, some are cross-shaped, and some are in other radiation shapes, which is very beautiful. How are these works made? It turned out that a cross mirror or other light mirror was added in front of the camera. After using this lens, all the light spots in the photo can emit corresponding flashes. It is ideal to shoot jewelry with this lens at sunrise. 8. Filter coefficient and increasing exposure level After increasing the filter, due to the increase of light blocking rate, it will have a certain impact on film exposure. The influence of low light blocking rate can be ignored, such as UV mirror, fog mirror and color gradient mirror.