How to buy a high-definition camera?

Lead: Compared with traditional cameras, digital cameras have incomparable advantages. Although the one-time investment in purchasing digital cameras is relatively large (800-2500 yuan), the future use cost is very low, and the application scope of digital cameras is quite extensive, which is loved by many individual users. How to choose a suitable digital camera?

How to choose a digital camera

I. Main performance indicators:

1. Pixel:

In the process of shooting with a digital camera, because the photosensitive element that receives signals is CCD, manufacturers often use CCD pixels as the specifications of digital cameras.

A digital camera that only judges how many pixels it needs can be judged according to the formula, which is: image quality, image size × the square of resolution.

If it is generally only used for daily photography, that is, the output of 6-inch photos in the development library (generally 150DPI), 6x5x150x150 = 700,000, then 800,000 pixels should be enough; If it is used to print 12 inch photos (the area is four times larger), then it is12x10x150x150 = 2.7 million pixels.

Our general A4 paper is 1 1 inch, so if it is used to print A4 paper, the camera is usually 3 million pixels.

It's just that many nominal pixels are "interpolated" pixels processed by software, not their own optical pixels. Pay attention to discrimination when buying. Generally speaking, it should be mainly optical pixels.

2. lens

The zoom multiple of the lens is directly related to the grasping level of the original object by the digital camera. The larger the zoom, the clearer the distant objects are photographed, and vice versa. Therefore, choosing a digital camera with large zoom can also effectively shoot distant scenery when you are away from home.

Zoom is divided into optical zoom (physical zoom) and digital zoom. What really works is optical zoom, and digital zoom only makes the dual-camera object display bigger in the viewfinder, which has no effect on the clarity of the object. Pay attention to the difference.

The lens caliber also needs attention. If the aperture is small, even the largest pixel can't be photographed well in the dark.

3. LCD viewfinder

There is nothing profound about the LCD viewfinder, mainly that the brightness should be high enough, the pixels should be large enough, and the larger the area, the better. At present, 1.5 inch to 2.5 inch is popular, as long as you pay a little attention when buying.

Two. Other performance indicators:

The performance selection mentioned above should be enough for our general choice. But if you care about details, you should also look at the following aspects:

1. Control mode of the flash.

Because most indoor photography needs to use flash, most digital cameras can't connect flash, so the control method of flash is very important. Digital cameras with good functions can support various lighting control modes. If you often take pictures of people, you should choose a digital camera with the function of eliminating red eyes.

2. Aperture and shutter

Aperture and shutter are very important indicators when purchasing digital cameras. A good digital camera can take clear and beautiful photos at hand, but some digital cameras need to use a tripod, otherwise the image will be blurred or weak and cannot be used.

3. Additional software

Because individual users buy digital cameras either to make web pages or to make family photos, videos and photos, they need to cut and modify files. If you can get practical image processing software when you buy it, it is not only very affordable, but also very convenient for future work and use.

Third, volume and shape.

In people's minds, the smaller the digital camera, the better. In fact, the small size of digital camera often means that the lens size is reduced, which means that it does not have the function of optical zoom, and the corresponding shooting and imaging quality will also bring some attenuation. This is where the digital camera is not satisfactory.

However, DC is always a consumer electronic product, and it is not necessary for people to blindly pursue the perfection of its functions. Enough to keep this moment wonderful. Therefore, for home users, small size, light weight, comfortable feel and convenient carrying are still important indicators for choosing digital cameras.

Of course, there are also some products that are relatively small and have good performance, which can satisfy our confusion in this respect. However, the price of such products will be very expensive.

Fourth, compatibility.

The compatibility of a digital camera depends on its battery and memory card.

At present, various brands of DC on the market use different forms of batteries and memory cards, which are full of personality and compatibility has become a big problem. The mainstream models are mainly SD and MMC cards, such as BenQ's 24 10. In addition to Sony's special memory stick, a few cameras still use CF cards, which are often too big for home use.

Digital cameras in Japan have always been stingy, and many 5-megapixel products are only equipped with 32M memory cards. So it's best to buy a large-capacity matching memory card. Of course, if you have the strength, you can choose the popular digital camera companion. At present, 20G and 15G products sell well.

In terms of batteries, lithium batteries are the mainstream of digital cameras, but some brands of cameras use their own special batteries, which are incompatible and expensive.

When traveling, you must consider the problem of battery life, otherwise the battery will run out, and you will not remember the splendid scenery, which is a pity. So, if you have enough money, you can buy large-capacity batteries or super-large battery packs from third-party manufacturers.

Of course, there are also many digital cameras that use the No.5 Ni-MH rechargeable battery with very good compatibility, and generally there will be no battery failure. For example, Samsung V3, V4 and other digital cameras are compatible with 6 or 7 kinds of batteries, which is very convenient for consumers.

In addition, it is worth mentioning that domestic digital cameras.

There is no doubt that price is usually the main consideration for all of us. The price difference has a lot to do with the brand.

Well-known foreign brands are mainly Japanese manufacturers, and we are familiar with Fuji, Sony, Canon and Olympus. Samsung in South Korea and Kodak in the United States are also major market forces that cannot be ignored. The price of mainstream models of these brands of ordinary consumer-grade automatic cameras is generally between 1000 ~ 3000 yuan.

Domestic brands of cameras are mainly domestic IT manufacturers, such as Lenovo, Ziguang, BenQ and Wenquxing. At present, the price of mainstream household DC of the same grade is between 500- 1500 yuan, which is far lower than that of digital cameras of foreign brands below the same grade. The price advantage of domestic digital cameras is exciting.

There are many bright spots in performance: for example, one machine can be both a digital camera and a camera; Another example is that the pixel is very high; Another example is the exquisite size ... I won't list them one by one, but you have to take a closer look for yourself.

Of course, the zoom lens of domestic digital cameras also has great shortcomings. Most of them have no optical zoom, only digital zoom. Therefore, if you need to shoot distant scenery frequently, you can ignore domestic digital cameras; But if you just shoot people around you, it is a very practical choice to use a domestic camera.

1, monitor camera definition selection. The definition of surveillance cameras is generally 420 lines for civilian use, and 480 lines are mostly 520 lines, 600 lines and 700 lines. The more lines, the clearer. The number of lines represents the sharpness of the camera, that is, the number of lines scanned horizontally by the display. Generally, more than 600 lines represent HD cameras.

There are many fake labels on the market, some of which are 700 lines, but actually there are only 500 lines, which is very different. We often take the actual test as the standard, and we can see the clarity with an ordinary TV.

2. Distinguish the appearance of the surveillance camera. Different shapes can be divided into hemispherical camera and gun camera. The hemispherical naming has the advantages of small size and beautiful appearance, and is suitable for installation in indoor, office, hotel corridor, elevator, corridor and other places with good concealment.

Hemisphere has a small focal length and is suitable for shooting nearby objects. Gun cameras are suitable for installation in all places, and there is no specific difference from hemispherical cameras. Other special-shaped cameras (such as flying butterflies, smoke sensors, pinholes and smoke sensors) are suitable for indoor places with special requirements.

3. Monitor the differences between camera lenses. Generally, 3.6MM and 4MM are wide-angle lenses, that is, the shooting range is relatively wide, that is, the horizontal range is relatively large, but people will become smaller when the distance is opened. Of course, things will also become smaller with distance, which is suitable for shops or family doors, that is, when the subject is 3-5 meters away.

4. Selection of monitoring camera interface. At present, the cameras on the market are generally BNC connectors, but recently the network interface and RJ45 interface are popular, which are ultra-high-definition cameras, but the price is higher.

Extended data:

Related knowledge:

1. Monitor camera lens

Focal length: The focal length of the surveillance camera refers to the distance between the lens and the photosensitive element. The magnification of a lens is approximately equal to the ratio of focal length to object distance. That is to say, with the increase of the focal length of the surveillance camera, the magnification increases, which can narrow the close shot and make the details of the distant view clearer, and vice versa.

Classification: surveillance cameras can be classified according to the size or aperture of the lens, and different types of surveillance cameras can be selected as needed when purchasing.

2. Photosensitive ability

In order to improve the clarity of the images collected by the surveillance camera, it is necessary to improve the photosensitive ability of the camera. The photosensitive element of CCD is 3 to 10 times that of CMOS, which can get optical signals better, then convert them into electrical signals, and finally process them into video signals for output or storage.

3. Control of monitoring camera

In order to maximize the observation range of the surveillance camera, the surveillance camera must be able to rotate. The method is to install a fixed monitoring camera by rotating the pan/tilt.

In addition, it must be able to achieve electric zoom and zoom. This requires that the camera in the surveillance camera can realize automatic zoom quickly and accurately. This has also become a standard for judging the quality of surveillance cameras.

4. Monitor the image transmission of the camera

The most widely used transmission mode is through the cooperation of analog cameras, digital hard disk video recorders and computer network systems.

5. Definition of terms related to surveillance cameras

(1) Resolution: The resolution of the monitoring camera in use refers to the number of points displayed in the horizontal and vertical directions of the screen. The higher the resolution, the clearer the image.

(2) Definition: The definition of the monitoring camera is expressed by lines, which are divided into horizontal lines and vertical lines. The more lines, the higher the definition and the clearer the image.

(3) Signal-to-noise ratio: refers to the ratio of signal electrical frequency to clutter electrical frequency in the surveillance camera, usually expressed in DB. The higher the signal-to-noise ratio, the better the surveillance camera and the better the image signal, that is, the clearer the image.

(4) White balance: White balance is an index to describe the white accuracy after the three primary colors of red, green and blue are mixed in the display. By adjusting the white balance of the surveillance camera, the color quality of the picture can be improved.

(5) Backlight compensation: When the camera shoots in a backlight environment, a black image will appear on the screen. This is a disadvantage for surveillance cameras that work 24 hours a day, so backlight compensation is needed. Using the backlight compensation function, if the camera detects that the video level of a certain area of the captured image is relatively low, it will increase the amplitude of the output video signal and make the image clear.

Baidu encyclopedia-monitoring camera

Skills of choosing professional cameras.

As a professional photography school, it can provide you with the most practical and professional skills when choosing a camera.

Different from digital cameras, digital cameras have an indicator of the number of CCD besides ordinary 1CCD digital cameras. We know that the images taken by cameras are actually produced by light. ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

Don't underestimate the accessories when buying a digital camera. Digital cameras are dominated by Japanese manufacturers, and the high price of accessories is because the pump is not used to press pliers and is not popular. In addition, in addition to some necessary accessories, you can interpret the words \ \ \ \ \ \ \ \ \ \ according to your own _ guide.

Usually, the camera comes with several accessories, such as charger, thin battery, AV cable, etc. In general, we need _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

In addition, more consumers buy UV mirrors, lenses, microphones, tape recorders, auxiliary lighting equipment and other accessories. In digital photography, V-mirror is not as important as ordinary camera, and generally only plays the role of protecting the lens from dust. Flash and other auxiliary lighting equipment _ colorful overseas Chinese play ⒉ ⒉ ⒉ 93

When buying digital products, most consumers are worried that they will be cheated by businesses with parallel imports. There are not many parallel imports and genuine products in appearance. Therefore, parallel imports are not as good as real goods. In addition, at present, most digital products have anti-counterfeiting labels. You can call the toll-free number designated by the manufacturer and check the authenticity of the products through the code on the label.

What if the merchant replaces your original machine with a parallel plane? First of all, you can compare the fuselage number with the external one. For example, you don't use domestic PAL. At the tip of the old gorge, the burden is on the ash, the shell of Xingfu is on the shell, and the shell of Klang Pin M is on the ground.

When buying a digital camera, many people will consider what brand of machine is good, and then they will look for this brand of products, but forget to buy a digital camera is also a good idea. It is very important to buy the brand reputation of DV machines, but it is still necessary to make a careful investigation of various models of machines of various companies, and then make a choice according to individual needs.

Skills of choosing high-definition camera lens

Lens-related experience "Six tips for choosing high-definition camera lenses". Hot topics in this article: HD, camera, lens, purchase, method, HD, camera, lens, choice.

How to buy high definition camera lens. Low-light surveillance cameras are more valuable than usual, so I must first know my needs when choosing. As an important member of high-definition products, users should first analyze their own needs when choosing low-illumination digital high-definition cameras. Low-light surveillance cameras are mainly used to monitor the financial system and road traffic, because these places have special requirements for pictures.

Method for purchasing high-definition camera lens

Also pay attention to the supporting products of the camera, because in order to realize the high-definition function, in addition to the low-illumination monitoring camera at the front end, the transmission system, the central system and the terminal flash system need to meet the requirements of bandwidth and tightness.

Secondly, if you want to buy a camera that suits you, you should also consider the camera technology. Below, I will provide you with ways to buy and inquire about low-light surveillance cameras.

1, query calorific value

Usually, millions of cameras are hot, and the primary reason is on DSP, so the stability is worrying. Together in the hot summer noon sunshine, more and more worried. It is worth mentioning that the original bolt is very hot. If infrared lamp is constantly added in front of the bolt, isn't it heating up? At that time, millions of low-light surveillance cameras were mostly high-light surveillance cameras, not low-light. Usually, the low-light intensity of a million-level low-light surveillance camera is 2- 10LUX, which is weak in sensing not only visible light but also infrared light. Therefore, if these millions of low-light-level surveillance cameras are to be used as infrared cameras, the number of infrared lamps is several times more than that of low-light-level infrared cameras. Perhaps, the current will increase, making the infrared lamp brighter. Having said that, we know that when choosing a million low-light surveillance cameras, we must check the calorific value of the machines and know what DSP they use. How about power consumption and fever. We may also understand why there are many manufacturers of millions of HD, but only a handful of manufacturers can supply and sell infrared millions of HD in batches. That's why. Here you are.

2. Query delay

As long as it is a digital camera, there are different degrees of delay. For the same 720P HD picture, some cameras only need 0. 1 sec, while others need 0.4 sec and 0.7 sec, which is much higher. Speaking of this, engineers are new. Why do they have different delays for the same resolution? Because digital cameras need three processes, compression, transmission and decompression flash. If a manufacturer relies entirely on the planner, it may lack the skills of the center, and it will lag behind others in image compression, network transmission and software power release.

Delay is a very important parameter, otherwise it will be very troublesome in PTZ control. Other delays also reflect the development strength of a software and the stability of the product. Imagine, if all the surveillance video processing is so tired, how to develop hundreds of thousands of digital HD surveillance?

3. Query the value

It is difficult for a manufacturer to make the value promotion simple, but it is difficult to make the value low. We can say, where is the difficulty? Isn't the value war often like this? Yes, but which company have we seen playing a value war, and can make an imitation camera for 30 yuan? No. Why? Because no one has adjusted the cost to such a low level, even cutting corners will reduce the cost at most 10. Let's think about it. In the early years, computers and CPUs were poor and expensive. Why are computers and CPUs so powerful and so cheap today?

4, query the low illumination

We should all know that digital cameras used for security monitoring and consumption are different from traffic monitoring, and can't keep flashing when the light is dark. Therefore, the use of Million HD is extremely limited because it has no low illumination characteristics. He went blind when the light dimmed. No matter how high the pixel is, it is also in vain. Coupled with civil monitoring, the demand for low illumination is higher, even more chaotic than some high-end monitoring projects intend to monitor the environment. For example, bank monitoring, 24-hour monitoring under strong light, conditions are very suitable.

5. Query tracking

This part of the original work is planned to use low illumination. Later, I thought about it. Because the trailing image is the most common shortcoming of millions of low-light surveillance cameras, I will discuss it separately. We have discussed the importance of low illumination, but some security vendors choose electronic slow doors or border stacking in order to raise concave-convex illumination. This will certainly greatly enhance the role of low illumination, but the disadvantages are also obvious. When there are moving objects on the screen, you will find people. When the object stops, it is clear.

6, query infrared

Infrared camera, isn't it just adding an infrared light to the usual machine? Too brief. Haha, many people say so. This statement seems to have some truth. Is it really that simple? Don't! If it's really that simple, why are there so few millions of high-definition infrared cameras on the market?

How to choose a home camera

Selection method of home surveillance camera;

1, high-definition pictures

High definition is particularly important in surveillance cameras. Today's 720P high-definition pictures have been listed as standard. General products can meet this requirement, but now more and more 1080P, 4k standards are applied to our surveillance cameras, so the high-definition performance of a good quality camera is very critical.

2. Network monitoring

Now our life cannot be separated from the Internet, and its convenience greatly affects our life. Due to the particularity of home monitoring, it is necessary to have the function of real-time monitoring on mobile terminals at any time. At this time, we can use smart phones to log in, freely watch our own security situation anytime and anywhere, and also support the detection and alarm function.

3. Storage mode

The storage of the monitoring system takes up a lot of money, and the same family users are also worried about storage. At present, there are two mainstream storage modes. One is the network-based cloud storage mode, where users can view video information from the cloud at any time without adding or maintaining any hardware locally by paying regularly or purchasing unprecedented storage. The future trend is to choose cloud storage mode.

4, the legitimacy of the product

Whether the product has been approved by the national public security department and issued a production license, whether it has passed the national 3C compulsory certification, etc. It should be noted that the 3C mark is not a quality mark, but the most basic safety certification. Some of its indicators represent the safety and quality of products, but they do not mean that the performance of products is equally excellent.

5, the practicality of the product

The choice of burglar alarm should be considered in combination with multiple factors such as building area, structural characteristics, property value and surrounding environment, but there are several general reference standards: wired mode has the advantages of reliable communication, strong anti-interference ability and low equipment cost, and is suitable for new buildings with reserved connecting wires in the wall; However, its mobility is poor and it is not convenient to adapt to the changing requirements of users and products.

How to choose a digital camera

Lead: The following are the tips on how to choose a digital camera. Welcome for your reference! I believe you have some common sense about how to buy a camera now. Remember Xiao Guan's suggestion when buying. Shop around and you will definitely choose your favorite digital camera. Hurry up and act!

How to choose a digital camera

1. lens

Like a digital camera, the lens is also an important factor to determine the imaging quality. The lens first depends on the zoom ratio, which refers to optical zoom. The larger the optical zoom ratio, the larger the size of the scene we shoot, which will bring great convenience to our composition when shooting, which is the same as the zoom lens of a camera. The second is the aperture of the lens. If the aperture is small, even large pixels can't be photographed well in the dark. In other words, it will become digital camera imaging.

2. Charge coupled devices

The pixel of CCD is one of the most important indexes to determine a digital camera. When choosing CCD, we should consider the following aspects:

First, the pixel of CCD basically determines the grade of digital camera. At present, the middle and low grades are generally around 800,000 to 6.5438+0 million pixels, and the middle and high grades are generally above 6.5438+0.2 million to 2 million pixels. Pixel size directly determines the clarity, color and smoothness of the captured image.

Second, quantity. 3CCD is much better than a single CCD camera, because the single CCD uses a single color to restore, and 3CCD uses each piece to restore one color, so that the three pieces are responsible for red, green and blue respectively, which will not cause color cast of adjacent pixels like the centralized restoration of a single piece, and 3CCD is better than a single CCD camera in both anti-shake function and minimum illumination, so it is of course necessary to choose an affordable 3CCD.

Third, the area. Don't underestimate the area of CCD. Other indicators are the same. The image quality of small area CCD is relatively blurred, and the color reproduction richness is also poor. The area used for shaking is also much smaller, and the anti-shake function is of course relatively weak.

Bottleneck. Third, brand, a good brand lens is superior in both imaging quality and light input. Now the better brands are carl zeiss lens and Leica lens.

3. Price

The reason why the price is put in the first place is because everyone basically has a psychological limit price when purchasing a machine. But Xiao Guan wants to remind everyone that two misunderstandings must be avoided in pricing.

First, avoid blindly pursuing low prices. If it does not conform to JS, then lowering the price is equivalent to lowering the performance. If the price is too low, the performance of your recorded material in terms of light and anti-shake will be much worse. As for how acceptable it is, it certainly varies from person to person. In my opinion, ordinary users under 4000 yuan should not consider it.

Second, avoid only pursuing high prices. Too much is not enough, but high prices will definitely improve performance. Here, we should pay attention to whether some performances are suitable for us, and some just improve the quality of photo shooting. For example, Sony's TRV 16E and TRV 18E are different from 750 yuan, but the main difference is that the latter is better than the former in still image shooting. However, if you already have or plan to buy a digital camera, you don't need to buy the latter.

4. Shape and volume

These two indicators are very important for home cameras. Users must focus on these two aspects if they want to play dazzling and convenient. First of all, the appearance of a machine is directly related to whether others will sneer at it or look envious when you use it. The machines used by our buyers are generally recreational, so we should consider the appearance. The other is size. Household cameras are generally carried with you when you go out, so it is very necessary to be small and exquisite, which can be carried easily and make room for your other supplies. The most important thing is that you can take any posture when shooting, and you don't have to limit the shooting angle because of people's standing posture.

5. Operation menu

Ordinary users may never play with numbers, so the simplicity of the operation menu has become a necessary condition for choosing a machine. At present, the operation menu of most digital cameras is very simple, but if there is really no foundation, there are two kinds of menus to choose from, Chinese menu and touch menu. Needless to say, the touch menu can be operated by pointing to the LCD screen, which is very convenient and suitable for digital beginners.

6. Still image shooting ability

A good digital camera can be used as a digital camera if your requirements are not very high, and the images taken with a camera are sometimes better than those taken with a low-grade digital camera. For example, Sony's DCR-PC/KOOC-0/20E has a maximum resolution of/KOOC-0/360x/KOOC-0/020 pixels, and Canon's MV6iMC still image has/KOOC-0 1024X768 pixels, which should meet the needs of ordinary users. You must pay attention to buying equipment. Although some devices can also take pictures, the images are not recorded on the memory card, but on the DV tape. You shouldn't expect any quality from this camera. If you have the idea of using the camera function, it is strongly recommended not to buy such products.

7. LCD viewfinder

You don't have to turn it off at ordinary times, because you are often familiar with shooting composition, and the machine is relatively large, so it is easy to shake when shooting with the viewfinder. But most users use LCD viewfinder when shooting. In fact, the LCD viewfinder is nothing profound. The main thing is that the brightness should be high enough, the pixels should be large enough, and the larger the area, the better. 2.5 inches and 3.5 inches are popular now, as long as you pay more attention when buying.

8. Accessories

Don't underestimate accessories, which also play a key role in the normal operation of your favorite machine, such as batteries. Generally, the shooting time of the battery is relatively short. If you have a better battery, you can open the viewfinder and take as many pictures as you want. It feels great. I'm using Sony NP-950 now, and it's never been affected by battery problems, because it will take a long time if I don't open the viewfinder. There is also a memory card, as well as various wires (matching with various models of machines), and some machines may have other accessories. Pay attention to check whether all the equipment on the cargo list has been delivered.

9. Guarantee

Generally speaking, the failure rate of digital products is very low. For example, Sony PD- 100AP in Xiaoguan has been in good condition for five years now. But nip in the bud is bad for our