How to distinguish the quality of Sunglasses

Judging the advantages and disadvantages of Sunglasses can be examined from both quality and aesthetics.Aesthetic has personal factors, and quality is standard.The quality of Sunglasses mainly refers to the quality of the lens.At present, the world's general standards are the standards of the US Food and medicine and Health Inspection (F D A) standard.

1. According to the F D A standard, while the lens guarantees the light transmission rate, it is necessary to filter more than 90 % of the ultraviolet rays in the sun, and the lens should be labeled "UV-100protct10n"."UV-400protct10n" tag, so it is very important to check the UV tag on the lens.

2. The lens must not have the "degree" of optical lenses.Generally, if the refractiveness exceeds 15 %, it will feel dizzy when wearing.

3. The lens must have a high strength and pass the impact test.Generally speaking, the strength of plastic film (propionic acid or acetate), resin tablets, and glass tablets from small to large.

How to distinguish the quality of Sunglasses lens quality

1,Material of the lens

glass lens: wear resistance, but relatively speaking, its weight is heavier than other materials, and it is also easy to break.

Popular resin lens: This kind of lens is lighter than glass lenses, impact resistance, and is not easy to break, but the hardness is low, so it is easy to get hair and it is easier to have scratches.

2. The refractive index of the lens

The higher the refractive index, the thinner the lens, the higher the price.Such as the optical characteristics of the lens:SunglassesIt is a flat -light mirror, which cannot be littering, and should not have optical defects that affect vision.

The simple method of identification is to place the Sunglasses in front of the eyes and observe the distant targets through the lens, such as window frames or door frames, and then move the glasses up, down, back and forth, the target should not be swinged and wavy deformation.

3. The color of the lens

Sunglasses are divided into dark and light colors without color distortion.The choice of the color shades of the lens should be depends on the places of the required activity. Selecting different colors for different light sources and different use occasions, the color of the lens will affect the Shading effect.To enable Sunglasses to effectively block the strong light in summer, dark Sunglasses are needed, but if you wear a bike or drive, you should not choose a lens with darker colors.In addition, when Sunglasses are used for daily driving, they also need to have the ability to identify different color signal Lights.

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[Types of Sunglasses] What are the types of Sunglasses?

What are the types of Sunglasses

When buying Sunglasses, many friends do not know which type of Sunglasses they need, simply pay attention to the ranking of Sunglasses brand, and choose according to their preferences.eyes, you need to take more care, so you should know more when choosing Sunglasses and less blind.What kinds of Sunglasses do you know?Let me introduce you in detail.

The Sunglasses can be roughly divided into the following:

1. Anti -light protection lens

This kind of lens can prevent strong light reflexes, allow you to see things from being disturbed in strong light, and clearer.The principle of this lens is actually very simple, that is, a layer of magnesium is applied on the surface.If you want to know if your Sunglasses are used in anti -light protective lenses, you can align the glasses at the light source. When you see the purple or green reflection, it means that there is a protective film on the lens.

2. color lens

This kind of lens is also called "dyeing lens". The Sunglasses using this lens can absorb the light of a specific wavelength. The principle is to add some chemicals during the lens production process to make the lens appear color.This lens is the most commonly used by Sunglasses.

Third, coloring lens

This kind of lens is actually the same as the color lens, but this kind of lens is generally used in a degree of Sunglasses. Among them, everyone is most familiar with "gradient -like coloring lens". The color is from top to bottom.From deep to shallow.

Fourth, polarized lens

The word polarization is used a lot in Sunglasses, but many people do not understand the specific meaning. In fact, this kind of lens is to filter the dazzling light emitted by the sunlight in an equal direction, and add vertical special coatings to the lens.outdoor sports (such as: maritime activities, skiing or fishing) are very suitable for use.

Five, color change lenses

Another name is "photosensitive lens".Originally transparent and colorless lenses, when encountering strong light, it will become a non -colored lens to protect the eyes. This is because this type of lens is added with silver chemicals.It is very suitable.

Sunglassesprecautions

If you understand these aspects, you can help when you buy Sunglasses. After buying, you must take care of your beloved Sunglasses!

1. What is the principle of night vision Telescope

1. principle

The microscopic night vision mirror (the same is true for the Telescope) to put the faint light, so under the circumstances that there is no light at all, the microcomio is not seen.

2. Principles of infrared night vision Telescope

This is the real military night vision mirror, There are two types of infrared night vision mirrors, one is active, the other is passive, and the active type is the night vision emitting a bunch of infrared rays. Essencequilt The dynamic type is to transform the infrared rays from the object itself into visible light. If there is no infrared source (most things that can generate calories can become infrared, such as creature, vehicles, flames, etc.), passive infrared night vision mirrors can not be seen. And active infrared night vision mirrors can be seen under any circumstances.

Second, night vision Telescope purchase

1. Active infrared night vision instrument applicable people: only at night.The main point of buying: The second generation is much better than the first generation. It is best to choose the second -generation night vision instrument.Try to choose the night vision instrument of your eyes, which is high, and it is much more comfortable to use than a single Tube.

2. Passive infrared thermal image instrument suitable for people: ultra -long night vision distance.The main purpose is to discover the goal, not to see the key points of the target details.

In summary, you must first know your needs. If you use it mainly at night, try to choose the night vision or thermal portrait.There are no two functions a volume, each with its own strengths.This can be practical.

Third, how far can night -view Telescope be seen

Many consumers do not understand this layer of concept. They believe that they can be seen one kilometer or two kilometers like ordinary Telescopes. In fact, these two products are not a concept. They are different.Observation.The principle is different, so when you look at the so -called parameters of the night vision instrument, don't believe in the indicators on the parameters. The most observation distance of the manufacturer's farthest observation generally has a large error and no reference value.Therefore, you cannot determine that the night vision is far away according to the parameters. The situation of the infrared auxiliary Lights is different. The distance of the situation of the infrared auxiliary light is different.In fact, this is very simple, but it is still difficult to explore than novices just exposed to this night vision instrument.Below I will talk about, under what circumstances can the night vision be seen?Under what circumstances is it close?

1 The night vision instrument observes a distance in the case of all black and light light

1) The distance from the micro -light observation is generally based on 1/4 The moon is based on the conditions of the weather. 50-400 Mi, if the weather is darker, or if the environment is harsh, its micro -light observation distance will be closer.At present, even the night vision instrument of more than tens of thousands of yuan can not be observed in the micro -light to reach 400 Above me.The second -generation night vision instrument can only be achieved 200 Du Mi, usually 1000-3000 The night vision around the yuan, its micr -light observation distance is 50 About meters.

2) In addition to the quality of the night vision instrument, the full black observation distance was seriously affected by the infrared lamp distance.At present, the infrared lamps equipped with the night vision instrument are average 50 About meters.Second generation The night vision can be observed under the observation of all black 100 About meters.In our actual use, there are very few all black conditions.For the second -generation night vision instrument, it is basically not all black when used outdoors.For a generation of night vision instruments, I said earlier, even darker, even if it was all dark.

2 The night vision instrument observes far and near the situation when the infrared is turned on and does not turn on the infrared.

At present, the night vision on the market, each model is different from the far exterior of the infrared and does not turn on the infrared.