The filter is made of plastic or glass and then added with special dyes. The transmittance of the glass piece is originally similar to that of air. All colored light can pass, so it is transparent, but after dyeing the dye, the molecular structure changes, the refractive index also changes, and the passage of some color light changes. For example, a white light passes through a blue filter, and a blue light is emitted, while green light and red light are rare, and most of it is absorbed by the filter.

 

Filters are used to attenuate (absorb) certain bands of light in the light or to precisely select a small range of light waves to pass through, while reflecting (or absorbing) other unwanted bands. By varying the structure of the filter and the optical parameters of the film, various spectral characteristics can be obtained, allowing the filter to control, adjust, and change the transmission, reflection, polarization, or phase state of the light.

 

Some optical components are precision instruments, especially optical filters, and the surface is easily scratched. Improper cleaning and storage methods can damage the filter surface film, reducing its application performance and shortening its service life. Therefore, the correct way of maintenance is extremely important. Let's take a look at the small details that the optical filter should pay attention to during normal use:

1. During normal use, it should be handled as carefully as possible, while paying attention to the external environment, avoiding the zipper, buttons and other scratches on the filter, or placing the filter in a dirty or dusty environment. in.

2. Take a finger cot when touching the filter to avoid salt and acid on the surface of the substrate.

3. When taking the filter, hold the edge of the filter. Even if it is with a finger cot, do not touch the light-transmissive surface of the filter.

4. The filter should be placed on a soft and clean object, not on glass, metal, table, or dirty paper.

5, should be placed in a clean capacitor paper or special lens cleaning paper when stored. The storage temperature is preferably around 23 ° C and the humidity is not higher than 40%. It is better to put it in a dry storage cabinet.

6. Do not stack the filters together to avoid wear.

7. If the surface is stained or fingerprinted, wipe it with absolute ethanol or a similar functional solvent. The specific method is as follows: wear a fingerless finger on the finger, soak the towel with absolute ethanol, and drag the edge of the towel soaked in ethanol to move in a single direction on the surface of the filter. Wipe the action as lightly as possible.