The function of polarizing filter

People's lives are also colorful, and people's lives are also good. For example, the use of high technology is also quite a lot, and the role of this polarizing filter is one of them. In fact, there are many in society, and the true meaning of this polarizing filter may not be known by many people, but everyone should not worry too much, because the Internet is relatively developed now.

In fact, different people have different views on the effect of this polarizing filter. Below is some information about the effect of this polarizing filter. At the same time, I hope everyone can make good use of it.

1. Improve the tint and color of blue sky. Polarizing filters can block part of the polarized skylight without or basically affecting the original tone (such as light and dark contrast Lb, black and white contrast) and color tone (such as color restoration, color contrast Lb) of other parts of the scene. Therefore, a polarizing filter can darken the brightness and tone of the blue sky with polarized light. This can not only adjust the tone of the sky to be more suitable and appropriate, but also reduce the contrast between the sky and the ground scenery, making the contrast and tone between the two more balanced and harmonious. At the same time, the polarizing filter can also improve the hue of the blue sky, making the blue sky in color photos bluer and more saturated, making the white clouds more prominent and vivid.

Because the entire blue sky is 90 degrees to the direction of sunlight projection. Therefore, the scattered light in the sky in the south, north and zenith in the morning and evening, as well as in the north, east and west (including the south in southern my country in summer) at noon contain a large amount of polarized light. Obviously, to obtain the best effect when using a polarizing filter to adjust and control the tone and hue of the blue sky, it is advisable to make the shooting direction exactly perpendicular to the direction of sunlight projection (that is, let the photographer's index finger and thumb form a 90-degree angle. When the index finger points to the sun, there is the most polarized light in the blue sky in the direction of the photographer's thumb. At this time, shooting with a polarizing filter can achieve the best effect of darkening the blue sky). See Figure 5-5. When taking landscape photos with black and white film, using a polarizing filter and a yellow filter in combination can create a picture effect in which the blue sky appears dark gray and the white clouds are bright and prominent.

2.Simulate night scene effects. In black and white photography, since the polarizing filter can darken the tone of the blue sky with polarized light, it is often used in conjunction with a red filter to shoot black and white film in the sun to simulate the effect of a moonlit night (the exposure should be appropriately underexposure).

Polarizing filters are also often used in color photography to darken the blue sky tones to simulate night scene effects under the sun. When shooting, face 90 degrees to the sun. The blue sky position at the corner was shot directly with light B-type color film without adding Leighton 85B, and the sky tone was darkened through the polarizing filter in front of the camera lens. To simulate a realistic moonlit night effect, the sky should be underexposed by about 1.5 levels when shooting, and light with a color temperature of 3200K can be used to provide appropriate fill light for the illuminated and backlit sides of the person's face. Although this method can be used for push-pull motion photography, horizontal panning is not suitable, so as to avoid the change in sky density when panning to different azimuth angles, which will make the film simulation "expose".

3. Improve the image clarity, texture and color saturation of the flare area on the surface of non-metallic objects. When ordinary white light shines on an ordinary object, the surface of the object will absorb part of the colored light and reflect another part of the colored light, so that the human eye can know the inherent color of the object from the reflected colored light. However, when high-intensity white light (such as outdoor sunlight) shines on the surface of a smooth object, the object will not only reflect a part of the colored light that reflects the object's inherent color, but will also directly reflect a considerable part of the total colored light emitted by the light source without absorption (if the light source is sunlight, this part of the reflected light is white light without showing any color). In the highlight areas of smooth objects, the intensity of the latter type of reflection is much greater than the former, resulting in bright spots and flares in the highlight areas of the object, diluting the hue of the object itself, making it tend to be or even appear to be the color of the light source, thereby significantly reducing the color saturation of the object in that area. For example, under sunlight, the bright spots on the roof of a car reflect strong white light, which often makes the color of the car body in that area unsaturated. For example, the green color of wet grass with dew and water droplets often appears lighter, and some green leaves and green grass on a sunny day reflect a large amount of blue skylight, presenting a tendency to be light blue and cold.

Through the above understanding and introduction, I believe everyone has a certain understanding of the role of this polarizing filter. At the same time, I also hope that everyone can be helped by the above knowledge. At the same time, I also hope that everyone will read more books about this polarizing filter, increase their common sense, and do more things that are good for themselves. This is the best.