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Do you know the difference between spherical and aspheric lenses?

The aspheric

When it comes to the lens, you have to mention the aspherical lens. In many people's understanding, the asperical lens is a symbol of high level, and the advanced lens is almost all aspherical lenses.

Let's start with what is called a aspherical camera lens. The aspherical lens is contained in the camera lens, aspheric is often calculated according to the surface, some aspherical lens side, the other is not, or both sides is spherical, and so on.

In general, a lens with two or more aspherical lenses is a very advanced lens. So, is the aspheric surface a very difficult technique?

We can look at it from the other side.

Now, in terms of glasses, the aspheric surface is also very widely used, and in fact, it is no more expensive than the spherical lens. For numerical control grinders, the wave surface can also be made.

Clearly, many people's understanding of the aspheric surface is still stuck in the leica 501.2 myth, which itself has long since been broken.

Of course, many people would still use the so-called "grinding aspheric", but don't say what grind the aspheric surface. I believe that for many people, it's impossible to tell whether a picture is not a spherical lens.

Is the aspheric surface necessarily good?

Even if it's a cock shot, it's impossible for each lens to be aspherical, the aspheric lens is actually a supporting role in the lens, not the main character, the main corrective, the correction function, after the use of aspherical lenses, the image of the edge of the image will be solved well and the picture will be more average.

So, is it a good thing to have an aspheric surface? From the current situation, the use of aspheric surface technology has become the standard configuration, especially the high technology index lens, for example, large aperture wide-angle zoom lens, it is difficult to guarantee the quality of the picture without the aspheric surface.

But in terms of our film fans, the aspherical lens we can use is relatively limited, after all, we use the camera mainly concentrated in the last century 60-90s, until the 90s, aspherical lens or less. Here we're talking about 135, and less in 120. We have seen that CAI has built so many classic Hau shots, such as the 384.5 on SWC, and there is no aspherical lens.

In a series of SLR lenses designed by Mr. CAI for nikon, many of them have no aspheric surfaces. But it doesn't prevent these lenses from being a good shot, like chase 50, 1.4 SLR, and the picture is average. Aspherical Camera Lens Better than a spherical lens camera  is ture.

Our client base spans across defense, security, bioengineering, pharmaceutical, institutional, industrial, and research industries worldwide. We specialize in DFM (optical assembly manufacturing) input from rapid prototyping to volume production. Our comprehensive metrology coupled with cost-effective philosophy can help Hyperion customers obtain a competitive edge in the global market.

1. Achromatic doublet lensis a kind of common lens. It consists of several groups of positive and negative cemented lenses with different radius of curved surface. It can only correct the axial chromatic aberration of red and blue light in spectral line. At the same time, the spherical aberration on the axis and the coma aberration on the paraxial point are corrected. This kind of lens can not eliminate the second-order spectrum, only the spherical aberration and chromatic aberration in the yellow and green wave regions are corrected. The spherical aberration and chromatic aberration of the remaining chromatic aberration and other wave areas can not be eliminated, and the image field bending is still very large, that is to say, only the clear image in the middle of the field of view can be obtained. It is advisable to use yellow-green light as illumination source or insert yellow-green filter in the optical path. This kind of lens is simple, economical and practical. It is often used in conjunction with correction eyepiece and is widely used in medium and low power microscopes. In black-and-white photography, green filters can be used to reduce the residual axial chromatic aberration and obtain good contrast photographs.

2. Complex achromatic doublet lensis composed of several groups of advanced lenses made of special optical glass and fluorite. The axial chromatic aberration is corrected by red, blue and yellow light, and the secondary spectrum is eliminated. Therefore, the image quality is good, but it is difficult to process and calibrate many lenses. The correction of chromatic aberration is in all wavebands of visible light. If blue or yellow filters are added, the effect will be better. It is the best objective in the microscope. It has good correction for spherical aberration and chromatic aberration. It is suitable for high magnification. However, it still needs to be used with compensating eyepiece to eliminate residual chromatic aberration.

3. Planar achromatic doubletlens is a complex optical structure composed of multiple lenses, which can correcting astigmatism and image field bending well, and make the whole field of view clear. It is suitable for microphotography. The correction of spherical aberration and chromatic aberration of the objective is still limited to the yellow-green wave region, and there is still residual chromatic aberration.

4. Planar achromatic doublet lens has the same degree of aberration correction as complex achromatic objective lens except for further image field bending correction, which makes the image clear and flat. But the structure is complex and difficult to manufacture.

Hyperion Optics is a premium supplier of photonics products including optical components, lens systems, and opto-mechanical assemblies from UV, VIS, NIR, to SWIR applications.

Our client base spans across defense, security, bioengineering, pharmaceutical, institutional, industrial, and research industries worldwide. We specialize in DFM (optical assembly manufacturing) input from rapid prototyping to volume production. Our comprehensive metrology coupled with cost-effective philosophy can help Hyperion customers obtain a competitive edge in the global market.

1、Technical principle

The curvature radius of the aspheric lens changes with the center axis. It can be used to improve optical quality, reduce the number of optical components and reduce design costs. Compared with spherical lens, aspheric lens has unique advantages, so it has been widely used in optical instrument, image and photoelectron industry, such as digital camera, CD player and high end micro instrument.

2、Comparative advantage

a, Spherical aberration calibration

The most remarkable advantage of aspheric lenses in replacing spherical lenses is that they can correct the spherical aberration caused by spherical lenses in collimating and focusing systems. By adjusting the surface constant and the aspheric coefficient, the aspheric lens can eliminate spherical aberration to the maximum extent.Aspheric lenses (rays converge to the same point and provides optical quality) basically eliminate spherical aberrations produced by spherical lenses (rays converge to different points and leads to blurred imaging).

Three spherical lenses are used to increase the effective focal length, which can be used to eliminate spherical aberration. However, a aspheric lens (high numerical aperture, short focal length) can be realized, and it can simplify the system design and provide the light transmittance.

b, System advantages

The aspheric lens simplifies the elements involved in optical engineers to improve the optical quality and improves the stability of the system.For example, in zoom systems, 10 or more lenses are normally used (additional: high mechanical tolerances, additional assembly procedures, and the improvement of antireflection coating). However, one or two aspheric lenses can achieve similar or better optical qualities. This reduces the system size, increases the cost rate and reduces the overall cost of the system.

3、Moulding techniques

a, Moulding of precision glass

The molding of precision glass is to make the glass material heated to high temperature and become plastic, and then molded by aspheric mold, and finally gradually cooled to room temperature.At present, the molding of precision glass is not suitable for aspheric lens with diameter greater than 10mm. However, new tools, optical glass and metrology process are driving the development of the technology. Although precision glass molding at the beginning of the hyp design has high cost (high precision mold development), but after the molding, the production of high-quality products can be split off the pre development costs. It is especially suitable for the needs of mass production.

b, Forming of precision polishing

Lapping and polishing are generally applicable to the production of monolithic aspheric lenses at one time. With the improvement of technology, the accuracy is higher and higher.The most remarkable thing is that precise polishing is controlled by computers and automatically adjusted to optimize parameters.If higher quality polishing is required, magnetorheological finishing (magneto-rheological finishing) will be adopted. Compared with standard polishing, magnetorheological finishing has higher performance and shorter time.Precision polishing molding technology need professional equipment. It is currently the first choice of sample production and small batch sample.

c, Hybrid molding technology

The hybrid molding is a spherical aspheric lens with a spherical lens as the substrate, which is cast on the surface of the spherical lens through an aspherical mould and cured by a layer of high polymer with UV light.Mixed forming is generally used the achromatic spherical lens as the base, and then a layer of aspheric surface is cast on the surface to eliminate chromatic aberration and spherical aberration simultaneously.Figure 7 is the manufacturing process of the hybrid aspheric lens. The hybrid aspherical lens is suitable for large scale manufacturing with additional characteristics (eliminating chromatic aberration and spherical aberration) .

d, Injection molding

In addition to glass aspherical lenses, there are plastic aspheric lenses.Plastic molding is the injection of molten plastics into aspherical molds.Compared with glass, the thermal stability and compressive resistance of plastics are poor. It requires special treatment to obtain similar aspherical lenses. However, the plastic aspheric lens is characterized by its low cost, light weight and easy molding. It is widely used in the fields of moderate optical quality, insensitive to thermal stability and little pressure resistance.

4、Basis of choice

All kinds of aspheric lenses have their own relative advantages. Therefore, it is very important to choose the right products for different applications. The main considerations include: batch, quality and cost.

Hyperion Optics is a premium supplier of photonics products including optical components, lens systems, and opto-mechanical assemblies from UV, VIS, NIR, to SWIR applications.

Due to the high production cost and complicated production process in the solar energy industry, the solar industry has a low efficiency. In order to improve the efficiency of the industry, solar R&D personnel continuously break through the technology, and the operators perform maintenance and inspection from the operation to optimize system running.

An infrared thermal imaging camera detects objects’ temperature distribution in a contactless way by showing a thermal image of objects being detected. Through the thermal image, we can have a quick and intuitive knowledge of the temperature distribution of the area, spot the place with high and low temperature, and analysis it qualitatively and quantitatively easily.

The main applications of solar thermal imaging camera are as follows:

Void welding and defects of the solar panel

In the operation of the solar energy system, the highest discovery rate is the defect of the battery component, and the surface on the infrared heat map is the "hot spot effect". The components of these defects cannot convert the absorbed thermal energy into electrical energy, but only It is directly expressed in the form of "high heat". Since the temperature is much higher than other batteries, the hot spot is clearly visible through infrared detection.

Dirt and shadow of solar panel

The performance of battery components covered by dirt and shadows will be greatly affected, not only cannot generate energy, the deposition of dirt may even affect the operation of the system, the polarity of the battery components affected by the dirt will change, and discharge phenomena may occur. Direct conversion to thermal energy creates a hot spot in the infrared thermography.

Solar Industry

Loose of solar panel line and conduction band

Loose or faulty lines often cause failures in the overall or regional components. Due to a poor connection, the current path will cause problems, and the temperature will rise abnormally. When it is detected by an infrared camera, it will show an overall heat condition. The same traits are also produced when the tape is not connected to the battery or is in poor contact.

Overview

D205B is widely used for ceiling lamps and has a large detection angle.The pyroelectric infrared sensor detects infrared radiation on the basis of the characteristics that the polarization of pyroelectric material changes with temperature.

Senba is the specialist PIR manufacturer for more than 15 years. We are the most advanced factory with complete categories. With strong R&D center, there are digital type and analog type, dual elements and four elements for you choose. The market cover domestic market, Korean, America, Turkey and Europe.

Features

Low power consumption

Wide angle

Slight movement can be detectable

Applications 

Ceiling Lamps

Home security systems

Home Alarm System. As its ability to sense warm, moving objects such as people walking into a room is coupled with simplicity and cost effectiveness.

FAQ

1. Can PIR Sensor for LED lightdetect animals?

PIR sensors are excellent in human and animal detection. They are mostly used in triggering an intruder alarm and activate household appliances upon the presence of a human.

2. Do PIR motion sensor for lightswork through glass?

No, alarm motion sensors do not work through glass. Most motion sensors use passive infrared (PIR) technology to detect motion. Changes in IR energy are not easily detected through glass. This is why motion sensors will generally not work through windows, which are usually insulated.