What's the use of color filters? Types and uses of color filters [detailed description]

The camera filter is an additional lens installed in front of the camera lens to filter natural light. The biggest advantage of the filter is that it is convenient for users who can't PS. With good composition and your own ideas, you can easily shoot creative works by pressing the shutter. Let me introduce you to the knowledge of camera filters.

The function of camera color filter Types and uses of color filters

1, red mirror (r):

Absorbing blue light can produce romantic sky effect or moonlit effect when shooting during the day, and it has the function of absorbing ultraviolet rays. When shooting, it is generally necessary to add three levels of exposure, which can be mastered flexibly according to shooting requirements and filter depth. This kind of mirror is generally used for black-and-white photos and can also be used for color photography. The filter functions of other colors are basically similar.

2, UV (ultraviolet) mirror:

The mirror can basically eliminate the influence of ultraviolet light and stray light on film sensitivity and protect the lens at the same time. Photography is more needed in plateau areas.

3. Blue mirror (b):

Used for black and white photography. Mirrors absorb red, orange and yellow through cyan, blue and purple light. When the wavelength is about 400-500nm, it is necessary to increase the exposure by about 2 levels (depending on the depth of the color lens).

4. Mirror of the sky:

Sky mirror is extremely light magenta, which can not only absorb ultraviolet light, but also absorb part of blue light and green light, so it has a certain effect on the color balance of the final picture.

5. Reflector:

The mirror is a rectangular reflector with positive reflection (mirror vacuum silver plating) and a pair of coaxial knobs at both ends (for adjusting the lens angle).

6. Gradient mirror:

Gradient mirror is one of the most important filters in photographic art creation. It can be divided into gradient mirror and gradient diffusion mirror, and can be divided into soft gradient and hard gradient in gradient form. Soft? That is, the transition range is larger, and vice versa, that is, the transition range is smaller, which should be chosen according to the creative characteristics.

7. Atomizing mirror:

This kind of mirror is a common filter for natural scenery photography, and is also widely used in advertising photography and portrait shooting. It can make the work have a foggy effect and increase the sense of atmospheric perspective.

8. Polarizer (polarizer):

PL mirror for short, this kind of filter can effectively weaken or eliminate the reflection of non-metallic surface. Polarizers can be used for black-and-white and color photography. Adding a polarizer to color photography can darken the sky while still maintaining other original colors of the scene.

Functions of various filters in digital cameras

Photography needs not only cameras and lenses, but also many small accessories, and polarizers are one of them. For outdoor landscape photographers, the use of polarizers is almost as common as UV mirrors, and it is also very simple to use. Can make photos look more transparent and brighter.

However, the role of polarizer is far more than that. It can also darken the sky and eliminate reflections, which is very useful when shooting water and glass. Polarizers can also block light and slow down the shutter speed. To understand the usage of polarizer, you need to master some theoretical knowledge. ? Polarized light? This word comes from physics. The reflection of nonmetallic surfaces such as glass and water is polarized light, while the clear blue sky is 90? The scattered light in the direction is also polarized light. These rays need to be avoided and polarized light can be eliminated, which can darken the sky and effectively reduce the influence of glare on photos. Polarizer can eliminate polarized light at a certain angle by using grating principle. Special attention should be paid to the shooting angle here. When shooting in reverse light or positive light, the role of polarizer is limited, and it must be at a certain angle with the light source and reflection.

Polarizers are very useful when shooting scenery, especially when the sky gets dark, which can make the color of the blue sky more saturated and highlight the clouds in the sky. However, extremes meet, so don't use polarizers too much. For example, the reflection of leaves and grass is polarized light, which is conducive to expressing details and layering. If these lights are eliminated, the picture will be supersaturated and have no sense of hierarchy.

The greater use of polarizers is to eliminate reflections, such as reflections on water and glass windows. In this way, you can shoot more details, such as things in the window, or rocks and weeds in the water. Moreover, the polarizer can reduce the amount of light entering the lens and slow down the shutter speed, similar to the medium gray density mirror.

Polarizers can be divided into linear polarizer (LPL) and circular polarizer (CPL). The former is mainly used for old manual cameras, because it will interfere with automatic exposure and camera metering system. At present, most polarizers on the market are CPL, so you should choose them according to your own lens caliber, and choose ultra-thin polarizers when shooting with wide-angle lenses to avoid dark corners.

When shooting scenery, learning to use a circular polarizer will have an immediate effect and make your photos look brand-new.

Install the filter correctly.

Screw the filter on the lens, keep it clean, wipe off the dust carefully, and avoid touching the lens with your fingers. Then slowly turn the polarizer, and you will find the change of light in the picture. The illumination direction of the light source and the angle of the reflecting surface will affect the final effect.

Set shutter speed

Pay attention to the setting of shutter speed when using polarizer. Polarizers can make colors more saturated, but also reduce the amount of light entering the lens. In order to slow down the shutter speed and affect the image clarity, it is best to ensure a safe shutter speed or use a tripod to shoot.

Rotating polarizer

After adjusting the exposure parameters, you can start shooting. Choose the composition, look at the viewfinder and turn the polarizer. You will find that the color of the sky changes greatly. You can also experience the influence of different light on polarizer from another angle.

Photo analysis

1. The polarizer reduces the reflection on trees and makes the green color more saturated, but it also retains the layers and textures of leaves, adding a touch of new green in spring to the picture.

2. The filter weakens the reflection of the lake, so that the foreground in the picture does not look pale, and more underwater details are presented in the picture.

3. Another advantage of the polarizer is that it can increase the contrast and make the photo more layered and deep.

Practical skills

Pay attention to the position of the light source

When using a polarizer, always keep in mind the position and angle of the light source to determine your shooting angle. When the sunlight is perpendicular to the shooting angle, the polarizer can play the greatest role. Adjust the shooting angle according to the effect you want to achieve.

Pay attention to the color change of the sky.

Because the effect of polarizer will change according to the angle of light source, there may be uneven brightness of sky color when shooting scenes. At this time, it is necessary to adjust the angle of the camera and rotate the polarizer to achieve the most natural effect.

Don't overuse the polarizer.

Although the polarizer is very useful, we should also grasp the degree. For example, with a wide-angle lens, the angle of the sky and the sun is different, and the darkening effect will be uneven. There is also the need to prevent the color from being too full, which will also damage the image quality.

Ensure correct exposure

Polarizers can reduce the amount of light entering the lens, and the shutter speed will slow down accordingly. At this time, it is necessary to prevent camera shake, check the histogram in time, and ensure the exposure of photos.

Eliminate the subtle influence of strong light and reflection, and improve the quality of landscape photos

Some landscape photos don't have calm water and large blue sky, but you still need a polarizer. For example, in the waterfall scene below, a polarizer is installed, which eliminates the pale reflection on the rocks below the picture, enhances the saturation of green moss and plants, and enriches the details of the picture. When shooting, don't just twist the polarizer in front of the lens, turn the lens more to find the most suitable effect. You can take more pictures and enlarge them on the computer to see the subtle changes brought about by different lens angles.