Why do I have pictures in my mind when I read the text? The feature is the landscape.

Digital cameras Digital cameras have entered the field of mass consumption. Many friends want to own a digital camera, but they don't know how to choose. As a digital product with high technical integration, there is an example of how to choose. People will pay attention to the number of pixels and resolution of CCD when buying digital cameras. In fact, the performance of digital cameras is more worthy of consumers' attention. I will tell you how to choose the "best digital camera" with practical functions from different angles.

Know the camera

Pixel resolution Pixel is the HyPic unit of digital imaging, and each pixel is a dot. Points (pixels) of different colors together make a moving photo. Digital cameras are often classified by pixels, but many people think that the pixel unit of CCD photosensitive point is actually not completely correct. Many manufacturers can make digital photos with higher resolution in the CCD photosensitive unit at the same photosensitive point through special technology, such as Fuji's SuperCCD. What about the pixel resolution between the two? How does the purchase time explain these two figures?

★ The higher the picture resolution, the more pixels are needed. For example, the resolution of a 640×480 image is about 3 10000 pixels, and that of a 2084× 1536 photo is 3 14000 pixels.

★ The resolution can have multiple values, and the camera provides higher resolution and higher flexibility to shoot and save pictures.

★ Image resolution and output imaging size and magnification. The higher the resolution, the larger the scale, and the higher the imaging and magnification.

The total number of pixels is the total number of pixels contained in CCD. However, due to the light irradiation at the edge of CCD, when you don't get a local shot. The total number of pixels in this part minus the effective number of pixels. When reading the product description, please remember to pay attention to the effective number of pixels that can be used in actual shooting, not the total number of pixels.

2。 The lens and shutter lens directly affect the quality of the camera. Under normal circumstances, the traditional camera manufacturers have a wide background, and the lens of digital cameras will be better.

★ The special specifications of digital cameras with focal length lens, most manufacturers do not predict the shooting range from these data, but increase the lens parameters of 35 mm focal length to the focal length value of traditional cameras. If it's a commemorative photo or a life photo, just buy a fixed-focus lens model, and a camera with more than three times the optical zoom capability with diversified requirements will be more suitable. Focal length, also called focal length, usually refers to the length from the image center that can be scanned clearly to the lens axis, and refers to the focal length of the lens group in the whole camera, in mm (millimeter). The longer the focal length, the narrower the angle of the visual range of the lens, but it has the effect of zooming off, just like a telescope with a lens; The shorter the focal length, the larger the shooting range and the smaller the relative object, which is suitable for shooting large-scale scenes, that is, the wide-angle lens we often say. For digital cameras, the longer the focal length, the longer the depth of the lens group can also be found in the data of camera lens f = 5.5mm or 5.5mm, but since the focal length of digital cameras is generally much shorter than that of general 35mm cameras, manufacturers have more similar words: 36mm lens is equivalent to 35 mm camera, compared with the users indicated on the packaging box.

★ Aperture range The larger the aperture, the more we can adapt to the lack of light. If there are more than two aperture values, the application flexibility of the camera will be improved. Aperture is one of the important mechanisms affecting exposure, which usually refers to combining the control devices of the lens group in a metal foil of about 5-9 to control the amount of light entering the inner lens and form rings with different sizes. The larger the aperture, the more light per unit time. The size of the hole is expressed by numbers. The larger the number, the smaller the aperture and the less the incident light. The lens mark is the lens with the largest aperture, which is the value in the fully open state, such as: 1:3.2, but in the zoom lens, you will see the mark of 9.2-28mm 1 :2.8-3 .9, indicating that the maximum aperture is F2.8 when the focal length is 9.2mm and 28mm when the focal length is F3.9. ..

★ Shutter Digital camera shutter can support 2? 11000 seconds can meet the general requirements. Of course, if they can have a wider shutter, they will be more suitable for various shooting conditions, such as fast-moving objects or quiet night sky. The shutter is used to adjust the exposure time of the camera, in seconds. On the basis of equivalence, 30,250 is average, such as 1/30 seconds, 1/250 seconds, so the lower the number, the slower the shutter speed. The faster the shutter speed, the easier it is to capture fast-moving images. Generally, the image caused by jitter is not easy to blur, but the high speed may lead to insufficient light. Usually, the high-speed shutter must use strong light or zoom with the aperture. Insufficient light is more suitable for slow shutter, but a tripod may be needed.

3。 We will take a closer macro shot of the macro theme, zoom and focus on the size you want. In macro mode, small objects with different digital camera functions may even approach the macro of about 0. 1 cm.

4。 Other functions, such as eliminating red-eye flash, white balance, exposure compensation, etc., will have greater flexibility in shooting in various environments. Photosensitive part

★ A digital camera with automatic white balance correction is equivalent to a traditional film camera. The photosensitive element of digital camera is fixed, so it is necessary to use the white balance correction ability to reflect the change of light source. It focuses on the sensitivity of different environments and designs. Different light sources will produce different degrees of chromatic aberration, which may make the color blue and yellow, and can be corrected and white balance corrected.

★ Exposure compensation, because cameras with automatic exposure function are compared with light gray of standard reflected light. When shooting an image, if there is too much white (too much reflected light), the amount of light will be higher than the standard value of photometry, so the camera will mistakenly think that the light is strong and narrow the aperture, resulting in underexposure of the photo and the white part will become less white. Exposure compensation For this case, exposure plus 1 or 2 cells has a bright and correct image. On the contrary, in most black states, the exposure of cells is reduced by 1 or 2.

Many consumers don't understand that the height of double-sided pixels in digital cameras is good. Actually, not at all. Buy digital cameras, digital and optical functions.

1 digital camera lens. The lens of the high-end camera is composed of several groups of lenses, including aspherical lenses, which can significantly reduce chromatic aberration and minimize graphic distortion. The material is made of expensive fluorite lenses or glass. The lenses of household and semi-professional cameras are made of synthetic resin in order to reduce weight and cost.

2 CCD image value of digital camera. CCD is the heart of digital camera, and it is also one of the main factors that affect the manufacturing cost of digital camera. Therefore, it has become an important standard for digital camera classification. At present, the entry-level product is 3-5 million pixels, and commercial and semi-professional users prefer 500-/kloc-0.0 million pixels.

Zoom of digital camera. Zoom optical zoom is real and will not affect the image quality of photos; Electronic zoom, digital zoom, it is based on the loss of clarity of local enlarged pictures.

4. Battery and power consumption of digital camera. The LCD screen and built-in flash of digital cameras consume more batteries than traditional cameras. Batteries are cheap and you can buy them everywhere, but the light won't last long. Therefore, it is the best choice for rechargeable lithium batteries. The mainstream digital products are designed for lithium-ion batteries, and a full set of charging equipment accessories are provided.

5 and other functions. More means using a digital camera, which is more interesting and flexible. For example, many digital cameras have video output function, which can be connected to TV to see photos. Some just want to set the startup screen and shutter sound, and you can use some short-term digital video recording functions. The driver installation of digital camera should be easy, and pictures can be downloaded and previewed quickly. For example, the software function attached to Canon digital camera is perfect, which can classify and manage pictures, and it is more diversified when printing, but it can also simply map images.

The decisive factor of the camera performance of an image sensor is that, in general, the maximum pixel value should be greater than the pixel value of the actual shot image? The image sensor is based on. Some manufacturers use software interpolation to increase the pixel value in order to make the image sensor lack pixels? In fact, interpolation can be realized by almost all image processing software, so its significance is not particularly great. What is the maximum number of pixels that must be based on the hardware pixel value when purchasing? An image sensor instead of outputting image values. one

A digital camera, called CCD (Charge Coupled Device), is a semiconductor component for photographing and recording information, not a thin-film silver salt camera. The size of CCD, such as TV, refers to the diagonal length of inches, such as 1.27 inches (note) ". The larger the pixel of CCD, the higher the sensitivity. Therefore, in the case of the same number of pixels and CCD, the quality is bigger and better. CCD size 1/2.7 inches (4.0 mm× 5.3 mm) 1/2 inches (4.8 mm× 6.4 mm)1/0.8 inches "(6.9 1 mm, such as 5.

Second, the four basic principles of purchase

The practicability of home entertainment has attracted much attention, but for ordinary home users, such powerful functionality and durability make cost-effectiveness the first factor. The market accounts for 3 million and 5 million pixels of the main models, meeting the imaging needs. A variety of shooting modes, a wide range of ISO values, high-speed and accurate focusing function are necessary, and a durable metal shell is also an essential consideration.

● For those fashionable and avant-garde consumers, outstanding close combination is the preferred standard function in design. Small size, bright colors and comfortable feel are essential, and some highlights, such as macro shooting, are icing on the cake for more such products.

● Professional users pay the most attention to the ultimate pursuit of image quality. Manual operation function is essential. Replaceable lens, CMOS image sensor with more than 6 million pixels and various image recording modes are the guarantee of high image quality. If the price of our camera set is explosive, more professional photographers will flock to it.

● The last thing to consider is where to buy it. The counter selling ordinary digital cameras will guarantee the "origin" of your camera. Buying a brand should be considered, because it is mainly to ensure the overall quality and after-sales service of digital cameras.

Preparation steps for buying a camera for the first time: make clear the purpose and purpose of buying a camera.

It is very important to determine the purpose and purpose of buying a camera. Only by knowing their needs can we buy the machine you really need. Otherwise, we may spend a lot of money on the rear camera, only to find that the function can not meet our own requirements, or it is not too multifunctional. We can consider the use of digital cameras. For example, some friends bought digital cameras to travel, and some friends wanted to learn photography. A friend wants to take macro photos. Of course, some people want to take close-ups of people or take photos of newborn children. In short, we must have a clear understanding of consumption.

For photo output, we also need to consider in advance whether we need to print a large number of photos or just from the screen point of view. Through this consideration, we can decide how many pixels of machines we need to buy. If we only print on the screen, a machine with 300- 10000 pixels is enough for printing, and you want to print above 10 inch, then we need to buy as many high-pixel cameras as possible.

Step 2: Determine the psychological level after confirmation.

The purpose and purpose of buying a camera should bear the psychological price according to one's own economic ability, such as 3000? 4000 or 6000? 7000 yuan can save us a lot of time and be more purposeful when we can choose. DC is still a luxury, so what we have to do is meaningless. What we give others is enough.

Step 3:

It is very important to collect data in the early stage and through various channels, so that we can have a certain understanding of the machine we bought. There are many ways to collect product information. First of all, digital cameras launched by many manufacturers will have a certain amount of publicity pictorial, so we can go to the manufacturers to have a look. Second, media advertising is a very important way. Nowadays, IT reporters have many advertisements for digital cameras, so we should pay attention to them. Similarly, many digital magazines or newspapers will also have a certain space, a digital camera or a review of digital cameras, we can buy some opinions.

If possible, you can download the manual of the corresponding camera, which is very beneficial for buying on the machine: on the one hand, it can make you more familiar with the machine, on the other hand, it can make you ready for basic operation when buying. I like reading instructions.

Appearance, function and other information, let us know about digital cameras. We should look at the actual photos, so that you can know the DC features you care about, such as color and quality, and we can go to the digital photography website to learn about them.

Step 4: Make a rough decision and collect the model.

A> product information is very important, which allows us to fully understand the characteristics of digital cameras, but looking at these data, we can only have a perceptual understanding. We just want to see the actual machine and even try some rational understanding, so that we can seize the opportunity, which is what we need to go to the mall. We can look at the prototype in the window or counter. The real machine may look different from the photo, and it may look better. We can also look at other people's machines and listen to what you are saying. Of course, we can also let enterprises' machines, some of which are actually operated by touch, ask the price. Pay attention to the counter-offer provided by the merchants when inquiring the price. Usually, in the room on the left, they will be asked to quote the prices of licensed or parallel imports.

Step 5: Choose the right time to buy.

When I decide to buy a machine, I must choose "auspicious DC". In fact, when I say "auspicious", I see the opportunity and the rapidly changing price of digital products, so it is very important to judge the market, but obviously, I should try to avoid buying before the holiday. Of course, buying a machine before the festival will not be very cheap.

Must-read in the field of buying cameras

When buying a camera, you need to check carefully. Don't lie down and buy defective products or JS (profiteer). Here, we give a detailed inspection step, as follows, there will be no problem:

65,438+0,000 yuan must be paid to JS, and the check has been completed;

See if the packaging is very old, very old, maybe someone else changed it, or a product saved by JS;

3。 Open the box to see if there are any trace accessories that are obviously separated from the box; Pay special attention to the battery pin without scratches;

4。 Check the machine appearance, body scratches, lens, LCD, EVF and shell;

Try to shoot and use an attempt to increase the flash;

Then take a closer look, zoom in, and you can get a clear picture from near to far. If you are not familiar with the machine you are going to buy, you can use automatic shooting when you try it out. Lcd and EVF are not bad. When your hand slightly blocks the camera, you can see a solid color image, or black and white in front.

7.DC, an important part of 7. CCD, if there are the above bad places, it will affect the shooting effect. It is not difficult to directly see that the CCD of DC is not good, so it is necessary to import the appearance of the picture PC. If the businessman has a computer, it is recommended to have a good OZ with the enterprise, and then go home and check in satisfactorily for testing.

How to test bad points

Usually, before we talk about how to test bad points, we must explain what bad points are. Simply put, CCD is always the bright spot. It never lights up, never lights up, rarely. So, why not? CCD manufacturing. Now the technology has been developed, but there is no guarantee that it will still be a very high output for the Convention to Combat Desertification. Like LCD may be defective, so we bought a machine and tested some.

The bad point test is a relatively simple test, and we can use two methods: one is the original image we see with our eyes. In fact, this method is more intuitive, but be careful, otherwise it will be easily overlooked. The second is to use software for testing. DEADPIXEL, the most popular bad point testing software, generally sells DC computer software.

Before the test, it is very important that we first take some photos of the whole situation that are all black and untested. Lens capping machine, we just need to cover the lens to shoot. If there is no lens cover, such as Casio, then we can put a flat desktop on the paper, point down at the DC lens and deduct the lens from the paper. It should be pointed out that the light must enter the lens, and it should not be too difficult to damage the machine.

The shooting parameters can be set to the maximum aperture and the shutter of ISO 100. We need to choose 1/60 and the slowest shutter. It is every different shutter speed.

After shooting, we can import the photos into the computer and then open the DEADPIXEL test. After opening the software, we can see the displayed interface, click the "Browse" button, select the photos we need to test, and then press the test button. In this way, the noise test of 1/60 photo will exceed 10, or we will try to replace it, otherwise the shooting effect may be affected.

Check whether the attachment is in the list. Usually, the number of random accessories will be specified in the details of the box. We can check according to the inventory.

Spare parts procurement

Of course, after buying DC, we need to buy some accessories, so that we can shoot better. Accessories are actually very important, and buying them may affect our normal shooting. Usually, we may need to buy memory cards, batteries and chargers, UV and adapter rings, camera bags and tripods. Some people like to buy a digital camera and watch it under the same roof. I don't think it is cheap to buy DC in these places. Except for the memory card, everything else should be bought in a special photographic equipment store, which is not only reliable in quality, but also cheaper in price. Let's talk about the purchase of these accessories in categories.

Memory card: When purchasing a memory card, you should consider your daily shooting day and combine your DC to determine the capacity of the card to be purchased. Secondly, we need to consider brand names. At present, there are many brands in the market, and brand names determine the quality in a certain sense. Such as Kingston (Jinshi) CF card and Toshiba) SD card, this brand of cards is not fast, but the quality is absolutely first-class and the compatibility is good. Third, consider the speed of the card. There are two kinds of cards sold now: ordinary speed cards and high-speed cards. If you need to take photos in RAW or TIFF format, try to buy a high-speed card.

Batteries and chargers: There are usually two kinds of DC batteries, a rechargeable lithium battery, an AA(5) battery and a nickel metal hydride battery. My suggestion is to buy rechargeable lithium batteries from regular stores. On the one hand, the quality is guaranteed, on the other hand, the probability of buying fake goods is not less than. Ni-MH battery and GP mobile Altman battery are not very expensive, but the quality is first-class. Of course, the products in this country are not bad either. We try to buy something with large capacity, such as 2000mAh. Chargers, now many digital cameras are given away at random, and the details that are not described are here.

UV and ring: the main function of UV digital camera is to protect the lens. There is no need to buy this. I think the first thing to look at is which machine. If the machine is relatively small, this is not considered, because an adapter ring or an adapter cylinder that usually relies on ultraviolet rays is installed on the machine, thereby increasing the size of the camera. If the machine itself is relatively large, such as Canon EOS350D, it is more suitable. There are many brands of UV, so it is recommended to consider multi-layer coating. When we want to buy UV ultraviolet caliber, if this is unfamiliar, we can buy a camera. With the general installation of UV, the random original lens cover may not be covered. We need a game.

Camera bag, must consider the location of discharge accessories, I hope to buy a machine. Therefore, it may buy a suitable camera bag, not the bigger the better, but the best. In addition, you should pay attention to the packaging materials and try to buy waterproof bags.

Tripod: You should pay attention to the stability of tripod, don't buy it. Besides paying attention to weight, if you are healthy and just need exercise, then this may not be a problem. The tripod of the most Li Weifeng brand on the market is cheaper, and anything can be used. Imported brands have a long history in Admiralty, Japan, and many top international photographers choose brands. The price is not very expensive.

Distinguish between technologies licensed for parallel import.

The guest asked me how to judge the mainstream identity of a licensed general, and I briefly said:

1。 Canon: There are anti-counterfeiting signs on the licensed packaging boxes. You can call to ask if you scrape off the coating. Box, warranty card serial number, ontology should be consistent; The laser anti-counterfeiting label on Canon Triple Warranty Card and the upper right corner of the warranty card are China, simplified Chinese instructions.

2。 At present, Fuji licensed products all have Chinese menus. If the menu is in English, it can basically be parallel. The packaging of licensed products is a simplified manual, a warranty card, and a Fuji licensed Fuji China Simplified Chinese warranty card, all in one.

3。 Minolta: You can call Shanghai Minolta's toll-free hotline: 8008200077, and verify the fuselage number.

4。 Nikon Nikon has no company in China, so several agencies are responsible for sales. The identification methods of authorized agents of Quantum, Lida, Liangchi and New Kang Hua are not exactly the same, but there are still some identification methods. Let's look at the warranty card first. The license warranty card is in English and stamped with the agent seal. Authorized to own simplified Chinese manual. Some drugs, such as quantum security labels, are stuck in a box. & ltBR/5 Olympus: Olympus machines now use simplified Chinese menus, but there are few products or English menus. Secondly, the manual and warranty card of China version are simplified, and the packaging is also simplified Chinese version.

6。 Sony can find the label authorizing Shanghai Suoguang or Wuxi Sony in the box, the warranty card Shanghai Suoguang, and the short description. The only Sony DC or DV sold in China market, as long as they are imported, are parallel imports. If the barcode on the package can see CN 1, if CN5 is parallel.

"7. Casio: the anti-counterfeiting label coating on the scratch-off sticker package bought by the customer. There are three ways to query the coating password:

1。 Call 8008 1083 15 for free telephone consultation or 0 10-642 19000 for consultation.

2. Call 800283 15 (Mobile) and 900283 15 (Unicom) for SMS service. "

Note: Now many good digital camera brands have their own websites. Log in to the corresponding website and enter the serial number. In just a few seconds, you can know that you are not allowed to buy DC or DV. If you are a DV or DC from a foreign country or Hong Kong, Macao and Taiwan, you'd better ask whether the country should be guaranteed. As far as I know, except Panasonic, other brands are not guaranteed in China. Does Panasonic guarantee all domestic products? At present, most maintenance departments sign contracts, and there is no formal warranty form, so the maintenance cost is staggering.

Pay attention to the share of digital cameras.

Are pixels equal to high-quality photos?

Many users will take the purchase of pixels of digital cameras as the main consideration. In their view, pixels are based on the quality level of digital cameras for the first time. A digital camera that looks like a high pixel is actually a high-quality shooting, and the proportional relationship between pixel and quality is as simple as that.

One thing is certain-pixels don't assume the quality of any decision. There are many factors that affect the quality of digital cameras. One of the factors that can directly affect the imaging quality is lens optical camera or digital camera. The lens cannot be ignored. The CCD photosensitive area used by ordinary digital cameras is smaller than that of conventional film, which requires strict resolution, or even if the number of pixels is high, the imaging quality will be poor for some reasons. In other words, it is more important to analyze the CCD pixel resolution of digital camera with optical lens than simply looking at it, so I chose a digital camera with high quality lens.

Clean, low noise, always accompanied by a high-resolution screen? ,

The impression of noise, low noise, clean screen and high photo effect always means that the imaging quality of ordinary users' digital cameras is the enemy. In fact, the situation of digital cameras is not so simple. The types of image sensors of digital cameras are only closer than those of a single CCD or CMOS, and the signal graphics engines of devices are relatively close. The processed image data creates different styles and models, different brands and different series, which is a performance of the core technology manufacturers, especially in the high-resolution and low-impact noise reduction technology R&D.

Is the higher the ISO, the louder the noise?

Slightly experienced digital camera users sometimes use high sensitivity settings when shooting moving objects or in dark environments. When shooting with high ISO values, the shutter speed is relatively fast, so it is not easy to get a high shooting percentage, but the image noise with high sensitivity will increase. In fact, many digital camera users have a headache, low sensitivity, difficult shooting effect, low noise and high sensitivity. Under normal circumstances, when we take high-sensitivity photos, we should reduce the resolution, so that the noise is not so obvious when we appreciate the photos. Simple analysis, this is because a pixel in the narrow image has changed at multiple levels, in other words, all three kinds of noise have become noise. This is not a strict explanation, but you can help us understand this phenomenon.

The pixel number of the effect is the best according to the high sensitivity setting of each camera, which requires the user's own practical experience. Let's make an analogy. ISO400 sets the minimum shooting noise of a 2 megapixel digital camera at 640×480 resolution, and a 5 megapixel digital camera at 1024×768 resolution, which can achieve good results.

The higher the number of pixels of CCD, the faster the focusing speed?

Let's take a look at the early digital cameras. Just because ordinary digital cameras have to read CCD imaging signals, focus, focus, and response speed, once the heart hurts forever, the first generation of high-pixel digital cameras. After each reading, the pixel data of the devices that improve the CCD signal are increased, and focusing, photometry and liquid crystal display also bring heavy burden. So we can often see that the low-pixel digital camera series is based on the same hardware platform, and the speed is often higher than that of the high-pixel "big brother".