Introduction to CPL/Polarizer
Circular polarization is mainly used to increase color density, deepen the sky blue, highlight white clouds, and eliminate the reflected light from non-metallic surfaces such as glass or water.
Circular polarizer, also called polarizer, or CPL for short, is a kind of color filter. The excellent function of the polarizer is that it can selectively let the light that vibrates in a certain aspect to pass through, in color and black and white
It is often used in photography to eliminate or weaken the strong reflection of non-metallic surfaces, thereby eliminating or reducing light spots.
The polarizer is made by bonding two layers of glass with a layer in between. The crystals are oriented to make a thin film, and these crystals are arranged in order. The polarizer is mounted on a rotatable frame. By rotating the frame at a high speed, it has several uses in photography:
A: Eliminate or weaken the reflection of non-metallic surfaces.
Such as glassware, display windows, water surfaces, reflective surfaces of paint and plastic surfaces.
B: Control the brightness of the sky to darken the blue sky.
When shooting outdoor or landscape photos, sometimes it is necessary to control the brightness of the sky tone of the screen to darken the sky, achieve the distance between the brightness of the sky and the brightness of the ground scene in the screen, and adjust the tone of the screen. For example, the blue sky and the white cloud tone are more prominent.
C: Increase the color saturation of color images
Polarizers can reduce or eliminate polarized light and eliminate reflected light while improving the color saturation of the image to varying degrees. In color landscape photography, the use of polarizers has received widespread attention, and the use of still life photography of flowers has also resulted in brilliant, clear and eye-pleasing color masterpieces.
Question: The image is blurry after using the polarizer.
Answer: If the indoor light is insufficient, it will prompt focus failure. It is recommended to try it in a place with sufficient light.
Question: The scope and occasions of CPL use
Answer: 1. Eliminate stray light;
2. Dimming effect;
3. Eliminate or weaken the reflection on the water surface;
4. Make the blue sky bluer and the water more stylish;
5. Eliminate moisture and dust in the air to make the transparency better.
Q: The light or angle used by CPL
Answer: 1. Shunguang——good
2. Diffuse light———good
3. Backlight——middle
4. It is 90 with the sun°Horn——good
5. At 45 to the sun°Horn——good
6. Facing the sun or accessories——Difference
Question: How to see whether the effect is achieved by rotating the CPL?
Answer: When shooting the subject surface stray light is eliminated(Half or all), Usually a little bit darker.
Q: Should I take off the UV mirror when using CPL?
Answer: The more lenses there are, the more there will be refraction. It is recommended to remove them as it is less likely to produce vignetting.
Q: How does CPL rotate?
Answer: It is best to turn it counterclockwise, clockwise will become looser, and may even cause the polarizer to fall off.
Q: Do I still need to buy CPL after buying a gradient gray lens?
Answer: Gradient gray mirror and CPL are different products. Can not be the same.
Polarizers and gradual gray are somewhat similar when used to darken the sky, but the principle is completely different. Polarizers only allow light perpendicular to the polarization axis to pass, and light from the other direction cannot pass. When rotated to a certain angle, the sky is Less light from above can pass through, which can highlight the effect of blue sky and white clouds. In addition, the biggest purpose is to resist the reflection of the surface of the shooting object, such as glass, water surface, metal plate and so on.