The general market price of polarizers ranges from a few hundred to more than a thousand yuan.

In high school, we learned that light is an electromagnetic wave, which is formed by the vibration of alternating electric and magnetic fields perpendicular to the direction of propagation.

This kind of wave whose vibration direction is perpendicular to the direction of propagation is called a transverse wave.

Sound waves are propagated by the forward and backward compression vibration of air or other media. Its vibration direction is the same as the propagation. This type of wave is called a longitudinal wave.

A characteristic of transverse waves is that their vibrations are polar.

In a plane perpendicular to the direction of propagation, it can vibrate in either direction.

We generally regard the direction of light wave electric field vibration as the direction of light vibration.

If a ray of light all vibrates in the same direction, we call it polarized light, or more strictly, fully polarized light.

Generally, natural light vibrates evenly in all directions and is unpolarized light.

However, the glare formed by reflection from a smooth non-metallic surface at a certain angle (called Brewster's angle, related to the refractive index of the substance) is polarized light.

If it deviates from this angle, some unpolarized light will be mixed with the polarized light.

We call this light partially polarized light.

Partially polarized light comes in degrees.

The greater the angle of deviation, the fewer components of polarized light will eventually become unpolarized light.

Polarized light sometimes brings disadvantages to our photography.

The reflected light on the surface of the glass prevents us from photographing the things inside the glass showcase, the reflected light on the water surface prevents us from photographing the fish in the water, the reflected light on the surface of the leaves makes the leaves turn white, and so on.

The clear blue sky also scatters polarized light in the vertical direction that is 90 degrees to the direction of the sun, which makes the blue sky less deep.

At this time, we need to use a polarizer.

Linear polarizers are generally made of polyvinyl alcohol film that has been processed by iodine dip-dying, etc., and are glued between two pieces of flat optical glass.

It can pass about 80% of linearly polarized light in the same direction as its polarization direction, and less than 1% of linearly polarized light that vibrates perpendicular to its polarization direction.

Through a polarizer, these polarized lights can be basically eliminated, and many photos will appear more saturated in color and clearer.

The specific adjustment method of the polarizer is as follows: Install the polarizer directly on the front end of the lens of a SLR camera or ordinary DC, and slowly rotate the adjustment ring of the polarizer while looking through the viewfinder (ordinary DC must be observed using the LCD, not the optical viewfinder)

) Observe the polarized light source in the subject until it disappears or weakens to the desired effect.

If the camera does not have an adapter ring and cannot install a polarizer, or you can only use side-by-side viewfinding, you can put the polarizer in front of your eyes and rotate the polarizer adjustment ring while taking the view until the polarized light disappears or weakens to the expected size, and then

On the premise that the orientation of the adjustment ring remains unchanged (that is, the direction indicated by the mark on the adjustment ring remains unchanged), move the polarizer to the front of the lens on the camera.

After that, the camera cannot change the shooting direction at will, otherwise the polarization direction of the polarizer needs to be readjusted.

Another thing to note is that when using a polarizer, it is not advisable to use a hood (obvious problem) because the filter needs to be rotated; the camera should be placed in the shadows as much as possible.