The bigger the lens size, the better?

You can find out how to choose a digital camera online.

Help you find some information, I hope it will help you:

A:

In the information forum, friends encounter more and more examples of wanting to buy digital cameras, but hesitating among various brands and models. I have used digital cameras for several years and bought them for others. Plus, I am an electronics major and have received the best professional education in digital electronic technology. I feel at least qualified to evaluate the choice of digital cameras for household consumption.

classify

At present, there are two kinds of digital cameras on the market for non-professional specific applications, such as Hasselblad large-format cameras with a price of more than 200,000 RMB, namely digital consumer cameras and digital single-lens reflex (DSLR) cameras. Here, the analytic difference of drawing internal structure diagram is avoided, and most people don't care about this. From the results, the main differences between the two cameras are that the former can't change the lens, the shortest focal length (which determines the maximum angle that can be shot, that is, the maximum range that can accommodate the scene in the picture) is generally not shorter than the latter, the photosensitive device is relatively small, and the general picture quality is relatively low; The latter can replace a variety of lenses with the same interface type, and the photosensitive device is larger and the image quality is higher. In addition, the former has a complete range of models from low to high in price, while the latter has no products below 6000 yuan due to cost reasons.

Considering that the average family's desire to buy is between 2000-4000 RMB, DSLR is not discussed here.

brand

Nowadays, the brands of digital cameras are numerous, ranging from Nikon and Canon Canon in traditional photography, to Sony, Panasonic, Toshiba and even Hewlett-Packard in computer industry, and then to Lenovo and Patriot in China. But my opinion is that the optical equipment in the camera, such as lens and electronic equipment, such as CCD/CMOS photosensitive devices, are actually difficult industrial products, and the manufacturing cost is 2000-4000 yuan. Either way, the first consideration is to save costs, not to improve quality or indicators, so there is no significant difference in quality or performance between products. Take a cup-thick lens of the cheapest single-lens reflex camera and compare it with a lens smaller than a contact lens of a household consumer digital camera. Whether the latter is Schneider's brand or Chase's brand, the difference in imaging effect may not be measurable by the machine.

In the era of digital photography, I personally appreciate Canon. In addition to the experience accumulated in the film era, after entering the digital era, Canon resolutely invested heavily in developing its own CMOS electronic photosensitive devices to cope with the CCD technology mastered by Sony. It can be said that the two core technologies are completely mastered. Nikon, which does not master the digital core technology, has been obviously passive to Canon in the launch of new products in the past two years. Sony has no optical experience, but it has the most mature CCD technology. The current strategy is to make up for its own shortcomings by joining hands with the German optical giant Chase to increase electronic functions. When I went to other homes, I was a little skeptical about buying Japanese CCD, adding German lens and assembling.

Therefore, if I don't care about my low cost and care about the brand theory, I personally admire Canon. As for supporting domestic products, patriotism is not a very rational reason, because the lack of core technology is even more serious than PC, and there is no price advantage. Off-topic, in fact, after the founding of the People's Republic of China, our optical photographic equipment manufacturing technology has been steadily improving. Although we took the road of imitation, Japan began to imitate German cameras at the end of 19, and it took nearly half a century to cultivate Canon and Nikon, which came from behind. But after the reform and opening up, our photographic equipment manufacturing system basically collapsed. Who is to blame? What's the matter? It is worth pondering.

index

Begin to enter the specific vehicle screening process. Let's talk about factors that have nothing to do with photography, because in fact, this is often more concerned by home users.

appear

With the maturity of the digital camera market, the entry-level products with a price of 2000-4000 yuan began to polarize and strengthen their competitiveness under the pressure of the decline in the cost of advanced products. The first level is the card machine, which develops to the size of a business card, emphasizing portability and fashionable appearance. Many card machines even omit the extension of the lens, and the periscope lens is built into the fuselage. Of course, the price is a shorter zoom range and a smaller maximum aperture. These optical parameters will be discussed later. On the other hand, emphasizing the large zoom ability can bring more and more distant objects closer to shoot, and the inevitable price is that the volume and weight cannot be reduced.

For example, my girlfriend's family is rich and bought her a digital camera a few years ago. At that time, everyone had little experience. They said to buy a good one, and the store recommended the most expensive one, Canon G3. We know that G series is basically the top series of Canon amateur consumer digital cameras, with excellent image quality and rich manual functions. But inevitably, it is big and heavy. I have bought it for several years, but my girlfriend doesn't take many photos with it. I often want to throw it away when I go out to weigh it. Determined to change the camera this spring, I chose Sony T33 wisely this time. Although in my eyes, T33 is not so much a camera as a card reader with a large LCD to browse photos, with the additional function of taking photos. But now she puts it in her pocket and takes it out and pats it easily when she is in a good mood and has scenery. Even after half a year, I learned from me that she didn't learn to focus when she pressed the shutter half, which is why she often can't take pictures clearly. But what does it matter? The camera is just for fun.

Short film shooting

Camera short film shooting can't be compared with digital camera DV, but by the same token, how many people are willing to take cameras and DV out to play? Moreover, DV is more expensive, with more technical traps, and it is easier to be slaughtered by profiteers. It needs more technical work to upload to PC for playing and saving. And to be honest, the increasingly powerful short film shooting function on digital cameras is enough to meet the most common video shooting needs such as blowing out candles together.

The support of digital cameras for short film shooting is quite different, involving the picture size (generally 320x200, the large one is 640x480), the number of frames per second (the larger the picture, the smoother it is, but it is generally linked to the picture size, and the larger the picture, the lower the number of frames), the mute sound, mono and dual channels, and the longest shooting time. Sony, Casio, Minolta and other powerful models. More than 640x480, more than 24 frames per second, dual channels, the longest shooting time is only limited by the remaining space of the memory card, and zoom can be used during shooting. Basically, short films are better than VCD. Canon is not doing very well in this respect. Most models have a limit of several seconds, which is not determined by the remaining space of the memory card. But in fact, the average user rarely takes more than 1 minute to shoot a shot, which is enough for most digital cameras.

Manual function

Simply put, it is to check the shooting mode of the camera to see if there are aperture priority (Av), shutter priority (Tv) or full manual (M) in addition to general auto, scenery and people. The last three technical details will not be mentioned here, and the average user will not care. But these manual operations can extend the life of your camera. For example, if you find that other people's night scenes are better than yours, your flash always jumps out by itself, and then the background becomes dark. If your camera has these manual functions, you don't have to rush to buy a more expensive new camera. Find a photography tutorial. So your machine can do it, too.

storage card

It is recommended that all photos be taken with the highest pixel, because the results are often smaller and better looking, and you may want to print and enlarge any one. The compression accuracy of JPG is very high, which is almost the same for ordinary people. In this way, each 4-megapixel machine is almost 2M in size and needs at least 256M memory card. According to the current cost performance, it is more cost-effective to buy a 1G card. But pay attention to testing when buying. Copy a compressed file with the size of 1G with a card reader and then copy it. Decompress and see if there are any mistakes. Any mistakes should be replaced. There are too many cards with problems now.

Sony MemoryStick and xD cards are the most expensive cards, and the others are similar, but the general trend is similar, so don't pay too much attention.

Battery type

The battery life of lithium batteries is often very long, but it is better to bring a charger or a secondary battery when going out. You can buy replacement AA batteries all over the street, but remember to buy brand-name alkaline batteries, or you won't be able to support large current. Although there is electricity, you will be prompted that you can't take a few pictures because of insufficient electricity. Generally speaking, the type of battery should not be the main consideration.

All right, let's get into the photography related parameters. Enter technical terms into Google for explanation, so I'm too lazy to go into details here.

pixel

It's simple. Now, in the autumn of 2005, buy a four-or five-megapixel one. Other functions are satisfactory. If the price is just acceptable, you can buy 3 million yuan, which is enough for A4 size printing. Six million, eight million? If you have enough money, the higher the better. It is inevitable to print a poster or two.

The dealer said that another company's model has high pixels but small CCD size, so it is better to buy my model. Again, 2000-4000 yuan, the difference caused by CCD size is only the concern of magazine reviewers. We just need to remember the number of pixels. After all, there is no technology that can squeeze twice as many pixels into a small size without greatly increasing the cost.

Shutter speed

Forget it. Now the shutter speed range of any digital camera is enough to cover daily use. Gate b? 1/4000 seconds? When you found that you needed a second advanced camera, you bought another one.

hole

The maximum aperture is best to reach F2.8. If you have f2.6 (such as some Kodak models), you should buy it first. The aperture size is inversely proportional to the number, but it should be written as 1/2.8 and 1/2.6. The advantage of a larger aperture is that you can use a faster shutter in the same situation, without fear of hand shaking and without a tripod. There is no tripod or flash to fill the light and improve the shutter speed. When there is insufficient light indoors or at night, the natural color and natural expression of the large aperture shooting results are as good as those of the flash shooting results. You will never want to turn on the flash again (except for professional external light sources, and professionals don't have to refute it here).

As mentioned earlier, due to structural reasons, it is sometimes impossible to reach the aperture of f2.8 For example, the Sony T33 mentioned earlier can only achieve F3.5 Everyone should pay attention to the small numbers written on the outer edge of the lens.

There are also factors such as focal length and depth of field, which will be discussed below.

Large zoom

Often want to shoot distant mountains or birds? Then buy an optical zoom of 6 times to 10 times instead of the usual 3 times optical zoom. Digital zoom? That's a lie. In order to make the total zoom ratio look great, it is all realized by interpolation, which is completely meaningless. If you have a 1 x digital zoom product, you can give priority to buying it, because the manufacturer is real, after all, it reduces useless functions, and maybe the cost will be transferred to useful functions.

The larger the focal length, the greater the influence of hand shake. Try to buy more than 8 times zoom camera with anti-shake function.

Generally, at the wide-angle end of a zoom lens, that is, the end with the smallest number of 28mm or 35mm, the maximum aperture can reach f2.8, but after lengthening the focal length, you will find that the maximum aperture is not that much. At this time, anti-shake and tripod are very important. You know, the cost of a lens that can keep a constant aperture is several times that of other lenses with the same parameter and non-constant aperture. Don't expect it to appear in the price range of 2000-4000 yuan.

Get something for nothing Large zoom has a price, that is, under the same aperture, the longer the focal length, the shallower the depth of field. Simply put, the narrower the scope of clear results. For example, if you photograph a bird, you may not see its background clearly, or even focus your eyes, and the tail of the bird behind you can't see clearly.

Of course, small depth of field is also used to blur the background of portraits, and it is very useful to shoot models. However, when shooting people at home, it is often necessary to combine the background scenery, but blurring is not appropriate.

The aperture price is the same. The larger the aperture, the shallower the depth of field. However, there are few aperture gears in general entry-level digital cameras, so we don't have to care too much about this factor.

These are what I want for the time being. Welcome to add. Generally speaking, I think the first digital camera for ordinary people is to buy a card machine just to arrange photos occasionally, and to learn photography, it is better to buy a camera with many manual functions, which is cheaper in short. It took me a year or two to take more photos before I understood my needs. At that time, the price of high-end and expensive indicators also dropped rapidly, so let's start with a better machine.

B: With the rapid development of computer technology, the boundary between mass products and professional products has become increasingly blurred, and many transitional products have appeared. However, digital cameras are indeed a unique market. The price difference between mass products and professional products is more than 10 times. The maximum for popular products is not more than 1 ten thousand yuan, and the maximum for professional products is not less than 1 ten thousand yuan. And there are few intermediate products, which is very difficult for an individual. The following are the elements of mainstream digital camera selection and some application experiences.

First, the choice of digital camera elements

1. Digital camera pixel

This is the most important index to measure digital cameras, but it is not the only one. Many friends who buy digital cameras will ask, "How many things does XX digital camera have?" It should be reminded that the pixels here are the actual pixels of the CCD in the digital camera, not the output image pixels, because some digital cameras use the CCD with 6.5438+0.3 million pixels and output the image with 6.5438+0.9 million pixels in the camera through some interpolation algorithm, which is harmful. I think the minimum pixel of digital camera used in semi-professional field is not less than 2 million, and the output image is not less than 1024X768. It is best to reach 2.5 million pixels. At present, Kodak DC290 230.4 million pixels are relatively high in mass digital cameras.

In addition to the number of pixels, there are many indicators to understand. The area of CCD is also an important indicator that has always been easily overlooked. From the production process of CCD alone, the smaller the area, the higher the integration, the better. From the point of view of photography, the general public digital camera uses 1/3 inch CCD. In order to obtain high-quality and clear images in such a small imaging area, a specially designed high-density imaging lens is needed. Therefore, even for the CCD with the same pixel, it is necessary to choose a large area CCD to ensure high-density and high-definition imaging.

2. lens

Regardless of digital factors, camera lens is the first factor in choosing a camera. Many photographers have been worried that the lens of a digital camera is less than a penny, and they think it can't be a high-quality image. In fact, it was a misunderstanding at that time, because the photosensitive element of digital cameras was CCD, and now the CCD used to popularize new digital cameras is generally 2/3, 1/2, 1/3 inches, which is much smaller than the traditional 35mm film, so the lens with a penny size is also much smaller for CCD. You can see that the maximum aperture value of a coin-sized lens reaches f2.8 (equivalent to f5.6 of a 35mm camera lens), which is unimaginable for a 35mm traditional camera. But then again, the larger the camera lens diameter, the better, because a large lens is conducive to the clarity of the imaging edge. A high-quality lens with a large aperture, multiple lenses and aspherical lenses is definitely the first choice for semi-professional photography. However, mass cameras generally use small lenses because of the price, and large lenses are also considered in my candidate models. The next important index of the lens is the focal length value. Many friends who are new to digital cameras may be shocked: what! 9mm lens says it's a small wide angle? Traditionally, the 9mm lens is also super wide-angle. In fact, the same reason. Because the CCD area is small, the nominal focal length value is also small. In order to facilitate comparison, manufacturers often give a comparison value corresponding to a 35mm camera. Another important factor is the zoom range, which is generally 2 times or 3 times. It is recommended to buy a product with a 3x zoom, because Volkswagen cameras are generally 35mm lenses, and the 3x zoom is just above 100mm, which is more practical.

Some digital cameras have introduced 2x digital zoom. In fact, digital zoom is nothing new, and 200 times digital zoom has been realized on the camera. However, the digital zoom on the digital camera was opposed by public opinion as soon as it was introduced, because it only enlarged the middle part of the image, and then the image quality was greatly lost through interpolation. Friends who have used digital zoom cameras should have a deep understanding of this. What's more, this function is easy to realize on a computer, and it is also an expensive decoration on a digital camera. Therefore, in the semi-professional field, image quality is a prerequisite, and the digital zoom function can be ignored when choosing a digital camera. For price reasons, the model without this function should be preferred.

3. Manual control function

Whether there is a manual control function is the standard to distinguish a fool camera from a professional camera. Manual control here means that you can manually adjust the aperture, shutter and focal length of the camera, which is very important for photography in semi-professional fields. Unfortunately, at present, only some popular digital cameras have this function, which is what I am most dissatisfied with at present. So digital cameras without manual control can't be used in semi-professional fields? It's not that bad, otherwise I have no choice, and I don't have to write this article. Some advanced mass digital cameras have the functions of some professional cameras, such as fixed-point metering and focus locking, which make up for the shortage of manual control to varying degrees.

C: Second, the application of digital cameras in semi-professional fields.

Digital cameras are not much different from traditional cameras when shooting. Here are just some notable places that appear in the semi-professional field:

1, the use of lighting

Friends who are familiar with traditional cameras will certainly find that there is a very important indicator that digital cameras have not even mentioned: the flash synchronous shutter speed. Just like a fool camera, although it has its own flash, it should be considered to work with an external flash in the semi-professional field. Electronic flash is the most commonly used photographic lamp, especially indoor photography, and more than three electronic flash lamps are often used. The external electronic flash relies on the light sensor on the electronic flash to sense the light emitted by the electronic flash connected to the camera and then flash by itself. The process of an ordinary electronic flash takes about 1/60 seconds, so the exposure time of a camera with a synchronous shutter speed of1/25 seconds will be adjusted to within 1/60 seconds to ensure the synchronous exposure of all external electronic flashes. At this time, the digital camera will be miserable! Of course, a few digital cameras with adjustable shutters can be spared, and most of them can't synchronize with the external electronic flash because the shutter is too fast. Even a digital camera with an external electronic flash connector can only synchronize with the connected electronic flash without shutter adjustment, and it is difficult to synchronize with other electronic flash. There are two reasons for this phenomenon: 1. Most digital cameras rely on the shutter to adjust the exposure and do not display the shutter value. At this time, the photographer can't guarantee that the shutter is within 1/60 seconds. 2. The synchronous shutter speed of flash of most digital cameras is above1125 seconds (this is found by the author after many tests). The most thorough solution is to replace the electronic flash with a more advanced halogen quartz lamp (color temperature 3200K, which is different from the electronic flash and has different effects, which will be mentioned later). Generally, each is 1000W, and at least two are used. Halogen quartz lamp shooting is always on, so there is no problem of flash synchronizing shutter speed, and the shooting effect can be seen on the spot. Each quartz lamp made in Shanghai has a 650 yuan, plus a soft box or a reflector with a tripod. In fact, each halogen is about 1000 yuan. Of course, the power supply of the studio should also be considered. Three halogen quartz lamp are on at the same time, which consumes a lot of electricity and has a high fever. This is no joke. There is no need to turn on the air conditioner in winter and summer. Method 2: There is an annular high-speed flash tube. According to the introduction, the flash synchronization can reach 1/500 seconds, which can basically be synchronized with digital cameras. However, there is still a problem with the shutter speed of flash synchronization. You must try it on the spot with your digital camera before you can buy it. The price of each one is the same as that of halogen quartz lamp.

2, color temperature adjustment

Friends who are familiar with traditional photography know that color film can be divided into daylight type and illumination type, in order to adapt to different light source environments. The color temperature of sunlight greenhouse is 5000K, and the color temperature of halogen quartz lamp is 3200K K. Digital cameras can't change films, so white balance adjustment is adopted, and both manual and automatic operation are carried out at the same time. Manual adjustment is flexible and can create unexpected artistic effects, but it is not so simple and difficult to master. Automatic adjustment can ensure that the shooting effect will not be greatly deviated, but it is difficult to create special artistic effects. For example, shooting with sunlight film and using 3200K quartz lamp as light source can create a warm atmosphere, and the skin color is yellow and red, which is a very common method in wedding photography. However, shooting with a digital camera and automatically adjusting the white balance are not as obvious as traditional cameras, but the shooting effect is also very good. The same lighting, the same model position, and different color backgrounds will make the model's skin color different. Different digital cameras have great differences in shooting. Photographers must experiment and explore different shooting environments and different digital cameras in order to achieve a clear idea of white balance adjustment.

We have finished talking about digital cameras here. Let's talk about printing photos. Digital cameras ultimately rely on printers to complete the whole process. At present, thermal sublimation is rarely used in photo printers, and color inkjet accounts for the vast majority. In terms of photo printing quality, Epson photo series is preferred, and photo-grade glossy paper and photo paper are preferred for printing paper. The printing quality is far from that of ordinary inkjet printing paper. In addition, the print quality of 1440dpi and 720dpi can be easily distinguished by the naked eye, which shows that the difference in print quality is not as insignificant as written in some articles. If the printing quality is still 1440dpi, the price paid is longer printing time and more ink consumption. It's time to print a perfect photo. Teach you a unique trick to ensure that the quality of printed photos is improved by three levels: cold-mounted ink-jet printed photos, choose a thin model in the middle, you can choose 10# film, and then compare it to see if it is equal to the photos.

D: digital camera purchasing skills

Time: (03-04 09:05) by Xiaoming

A digital camera with an electronic storage device as the record carrier, under the control of the aperture and shutter, realizes "exposure" on the electronic storage device through the optical lens, and completes the recording of the captured image. Compared with the traditional photography technology, the digital camera greatly simplifies the process of image copying and can display the photographed photos quickly and simply. At present, there are nearly 100 kinds of digital cameras, and the common brands in the domestic market are Kodak, Olympus, Fuji, Canon, Casio, Epson, Agfa and Polaroid.

The first thing to buy a digital camera is the image quality. In addition to the lens quality, the imaging quality of a digital camera largely depends on the pixel level of the imaging chip. The more pixels, the higher the pixel level, the higher the resolution of the image, and the more delicate, clear and distinct the picture. The pixel level of low-grade digital cameras is generally low, with pixel points ranging from hundreds of thousands to hundreds of thousands; The pixel level of mid-to high-end digital cameras is relatively high, with most pixels above 654.38+00000. The higher the pixel level and resolution, the higher the grade and price of the camera, and the better the imaging quality. When buying a digital camera, if financial resources permit, the higher the resolution, the better.

But don't blindly pursue high resolution, do what you can according to the purpose of use. Usually you shoot to display on a computer screen or design on a web page, so you can choose an economical and practical camera with a resolution of 640×480. If you want to output images and require photos to be relatively clear and realistic, you should choose a camera with a resolution above the medium range; If you are a professional photographer or editor, you should choose a high-resolution camera.

Secondly, the choice of storage media (shooting number). The storage capacity of a digital camera determines the number of photos you can take. The larger the storage capacity, the better. For example, Casio QV- 100 and QV-300 can take at most 192 photos. At present, most cameras can use a portable memory card, which brings convenience to the expansion of capacity. Like a negative, you can change another memory card to continue shooting after shooting, which greatly increases the number of shooting.

The choice of lens quality can not be ignored. Nowadays, most digital cameras use built-in zoom lenses, and aspheric lenses are used as mirrors, and the number of apertures has also increased from 2 to 3 to about 6. The aperture of the lens is also obviously enlarged, and there are various zoom lenses, which greatly improves the shooting flexibility and imaging quality; Some cameras are especially suitable for outdoor people and have electronic zoom function, which can improve the ability of long-distance shooting.

Automatic zoom function. Early digital cameras are similar to low-grade "fool" cameras, with poor focusing accuracy, single exposure mode and narrow range. In recent years, more and more digital cameras adopt CCD and TTL auto-focusing methods, which further improve the focusing accuracy and greatly improve the image quality. In the exposure mode, there are shutter priority automatic exposure, aperture priority automatic exposure and manual exposure modes, and consumers can choose according to their own photography skills and habits. ?