What is a digital SLR camera? What are the characteristics compared with ordinary digital cameras?

First of all, there are great differences between the two in the way of framing.

Digital SLR's framing method is very different from it. It adopts the same "single lens reflection" framing technology as the traditional SLR camera, and consists of a complex reflector and a pentaprism to form a pure optical framing system. Generally speaking, optical viewfinder can be divided into two framing modes, namely paraxial head-up and single-lens reflection coaxial framing, of which the latter is a very professional framing mode, which can ensure that the scene seen during framing is the scene that will be shot completely through the lens. However, with the rapid development of digital image products, electronic LCD viewfinder has a great potential to catch up with it, because it has many characteristics that optical viewfinder does not have. For example, the image displayed by LCD viewfinder is basically the effect of taking pictures, and it can also display many performance parameters and shooting information, which greatly improves the usability of the camera.

Tips: Ordinary public digital cameras can use LCD to view the scene, and can directly preview the possible shooting effect, but professional digital cameras can't. This is because the non-professional digital camera uses the lens integrated with the fuselage, and adopts the inter-mirror shutter, which can be opened normally before the official exposure and closed before the official exposure. Usually, the light can directly reach the photosensitive device, so LCD framing can be easily realized. Professional digital cameras are mostly based on the traditional camera body design, using focal plane curtain shutter and reflector, so the light can not reach the photosensitive device before the official shooting, and it is not easy to realize LCD framing. Since SLR models have adopted TTL optical framing, LCD framing is unnecessary.

Another important difference is the size of the imaging device. Most low-end DSLR's (such as Canon 300D and Nikon D70) use 15. 1x22.7mm similar to APS film specifications, and some professional digital SLR cameras even use 24x36 full-size photosensitive chips, such as Canon 1 Ds and Kodak Pro/N/Cn/C.

The size of photosensitive chip has a great influence on the imaging quality of digital camera. You can't just look at the number of pixels, but also look at the size of each pixel. For example, most of the low-end DSLR pixels are only about 6 million (the number of high-end DSLR pixels can reach more than100000), while the consumption flagship has generally reached 8 million pixels. From the perspective of the number of pixels, the consumption flagship pixel number is obviously higher, but the pixel is only one aspect that determines the image quality, and it is not very important.

Pixel height has little to do with image quality, and pixel promotion only improves image resolution. Other factors that affect the image effect, such as purple edge, noise, glare, dispersion and distortion, will not improve with the improvement of image resolution. On the contrary, it will get worse with the increase of pixels. For example, in noise control, if the number of pixels (photosensitive units) is simply increased under the condition of constant CCD area, the distance between photosensitive units will be greatly reduced, leading to more optical and electromagnetic interference, and finally the noise will rise sharply. At present, the 8-megapixel DC product is 2/3 of the original 5-megapixel CCD. Therefore, users generally feel that the image quality of some 8 megapixel DC is not as good as that of the previous generation 5 megapixel products.

Thirdly, there is a big difference in size and weight between DSLR and consumer flagship. Although consumer flagship is getting bigger and heavier (such as Sony F828, which weighs nearly 1kg), some DSLR are getting smaller and smaller (such as Pentax *istD, which only weighs more than 600 grams). However, SLR cameras should also consider the problem of lens matching, not just the size and weight of the camera body itself. In this way, the result is obvious. For example, the 8-megapixel consumption flagship has a lens of 28-200 mm (equivalent to a 35 mm camera), a maximum aperture of F2.8, and weighs only about 1.5 pounds, so it can be put in a coat pocket. However, DSLR lenses with similar focal lengths and aperture ranges require at least two lenses. The size and weight of the lens alone are huge, and it needs a medium-sized camera bag to fit it.

But like many dilemmas, there is no perfect choice between DSLR and consumer flagship. Both have their advantages and disadvantages. Let's take a look at the advantages and disadvantages of DSLR and consumer flagship:

Second, the main advantages and disadvantages of DSLR and consumer flagship

Let's first pay attention to the main advantages of DSLR:

More advanced image sensor. The image sensor used by DSLR is large in size,

Therefore, the sensor area occupied by each pixel is equivalent to about 5 times of the consumption flagship, so the signal-to-noise ratio is excellent and the color brightness range is wider. The quality of photos taken at the sensitivity below ISO400 is very good, and at the high sensitivity setting above ISO 800, the noise can be kept low and the shooting quality is good.

There are many kinds of interchangeable lenses, including super wide angle, telephoto, macro, soft focus and optical anti-shake lenses, which can meet the needs of different users and consumers have great freedom of choice. In addition, because the sensor area is large, the imaging effect with low-resolution lens is also good, which is another advantage of DSLR.

Because of the large cache, DSLR can achieve high continuous shooting speed, even if it is set to RAW format, it can also have fast continuous shooting speed. Moreover, due to the adoption of a focusing system independent of imaging elements, it has the same reaction speed as the traditional SLR camera, and the optical framing device with brighter, clearer and more real-time EVF has obvious advantages in sports photography and capturing emergencies;

More accessories. Rich components are the necessary guarantee for digital SLR cameras to complete shooting. In addition to rich lenses, high-power flash, macro flash, high-power battery, infrared remote control and other components are also available to ensure that users can take excellent photos.

Nikon D70

Nikon D70

More professional taste. Because the design and production of digital SLR cameras need high technical strength, this product has been branded as a distinctive professional brand since it was launched. Unique framing method, professional body design and material selection, and richer manual functions all make users enjoy more shooting fun.

Let's look at the main disadvantages of digital SLR:

Pure optical framing can not provide richer information such as real-time histogram;

If equipped with a large aperture and long focal length lens, the volume will be quite large and the weight will become very heavy;

Because the lens can be changed, the exposed photosensitive chip (CCD or CMOS) is easily polluted by dust;

When shooting in a quiet environment, the noise of shutter and mirror is very harsh, and a short black screen will appear at the moment of shooting.

Video shooting function is an impossible task for digital SLR cameras, because the structure of the mirror has decided everything.

Main advantages of consumption flagship:

After including a large zoom and large aperture lens, it can still keep small size and light weight, and the focal length and aperture range of this lens can meet the shooting requirements of more than 90%;

It is quite quiet when shooting, and there is almost no noise of shutter and reflector;

It has many functions, such as shooting audio and dynamic video. Although there is still a big gap between the recording effect of dynamic video and digital camera, this function is really convenient for many users and has certain usability.

When the low sensitivity is set below ISO 100, the shooting quality of photos is still good.

There are rich information such as real-time histogram when shooting through EVF or LCD, and the rotatable LCD can facilitate shooting at different angles;

Most products can get good macro shooting effect without additional lens or device;

Because there is no problem of replacing the lens, the body is almost completely sealed, so the photosensitive device will not be polluted.

Minolta A2

Main disadvantages of consumption flagship:

The imaging quality is worse than that of DSLR, especially when the sensitivity is above ISO 100, the picture has obvious noise.

The accuracy of EVF or LCD is not enough, and the delay problem is serious (Minolta A2 is slightly better);

The focusing speed and shutter speed are usually slower than DSLR, because the buffer capacity is not too large and the continuous shooting speed is limited;

When taking photos in RAW format, the interval between each photo is usually 5- 15 seconds (Minolta A2 and Canon Pro 1 are exceptions);

The lens cannot be replaced, so it is difficult to meet the special requirements of photographers. Although the focal length range of the lens can be increased by adding a wide angle or a telescope head, the quality is poor.

Third, related topics of digital camera image quality

The quality of the photos taken is related to many factors.

It's not only a question of consumer flagship and DSLR, but also has a lot to do with different manufacturers. For DSLR, the quality of photos has a great relationship with the lens used. Lens is the soul of a camera, and digital cameras are no exception. Because the imaging area of a digital camera is small, it is also highly sensitive to the quality of the lens, and the physical aperture of the lens must also be considered. Regardless of its relative aperture, the larger its physical aperture, the greater its luminous flux and the better its imaging quality. In addition, adding a special coating on the lens will greatly improve the imaging quality. Therefore, the use of high-quality lenses with large aperture, multiple lenses and multiple groups, including aspherical lenses, can effectively improve the picture quality.

In addition, how the camera handles the pictures it takes is also very important. Different manufacturers have different ways to process pictures, which leads to different quality of pictures. For example, some manufacturers treat the saved JPG files very clearly or brightly, while others do not, which makes the quality of JPG images vary greatly. For example, some Sony digital cameras have very bright colors, while Canon DC has neutral colors. Therefore, the best way to compare the quality of pictures taken by digital cameras scientifically is to set them in RAW format.

In terms of the number of images of the photosensitive chip, for users with special requirements, such as users who have high requirements on the quality of printed pictures and often print large-size pictures, the benefits brought by high pixels are remarkable. In addition, high-pixel pictures are also beneficial to the later cropping of images. For many ordinary home users, in fact, 3 million-5 million pixel products are enough. In fact, whether it is 6 million or 8 million pixels, whether it is a consumer flagship or a DSLR, the photos taken by these cameras are enough to output A3-sized photos, while general home applications basically do not need to output large-sized pictures. For photography enthusiasts, they are interested in 8 megapixel products because this type of digital camera can not only output large-size images, but also be closer to professional SLR digital cameras in camera function design, which can meet special creative needs.

When we pursue the number of pixels and image quality, we should also consider the main purpose of buying a camera ourselves, and carefully compare the 8 million pixels taken by the flagship consumer with the 6 million pixels taken by the DSLR. We also need to find out what the specific meaning of image quality is. Is it noise? Contrast? Clarity? Or color accuracy? Perhaps recognizing these problems is more conducive to our choice of suitable products.

Fourth, who should DSLR and consumer flagship choose?

In the past, this problem was easy to consider, because the performance and price of the two are completely different, and the user groups they face are also completely different. But now, with the flagship pixel consumption increased to 8 million, the price of digital SLR body has dropped below 10,000 yuan, and the choice is even more difficult.

Simply put, the consumer flagship can get more functions at a lower cost, such as having a video shooting function, without investing more money in the lens. Small in size, easy to carry and flexible in framing, suitable for ordinary photographers to buy. However, the biggest drawback of this product is that the picture quality is average and the shallow depth of field effect is not outstanding. DSLR has the excellent image quality brought by large photosensitive devices and the advantage of supporting lens replacement. It is suitable for friends who really like photography and pursue photo quality and have traditional SLR lenses to buy. The image sensor used in digital SLR is also CCD (or CMOS), but the sensor size is much larger, and the sensor area occupied by each pixel is more than five times that of consumer flagship DC, so the image quality is much better. And more lens choices, from super wide angle to super telephoto, from macro to soft focus, make photography fun grow infinitely.

Of course, both have their own strengths, and there is no question of who is good or bad. We must make a choice according to actual needs. Just like in a traditional camera, if you want to have a quiet shooting effect, you need to choose Leica products, but if you want to shoot at a long distance, you need to choose a SLR camera with a telephoto lens.

Undoubtedly, if you often need to shoot wild animals, Canon 10D+80-400 mm IS L lens is your good choice, and if you just like to do some random shooting in the street, Minolta A2 and even Sony T 1 are your good choices. If the job requires it, maybe you should have both.

Now there are some consumer-grade flagships, which provide very good image quality, such as Panasonic LC 1, which not only has good image quality, but also looks and controls like a traditional camera of Leica. The new 8-megapixel product has better performance in this respect, so in my opinion, the consumption flagship has more advantages. With the development of technology, professional photographers can now find a consumer flagship that meets the requirements, which was impossible a year ago. For most amateur players, the consumption flagship is a very suitable choice. There is no doubt that Canon's 1Ds is a very good photography tool, which can take very high-quality photos, but if I want to travel for more than three days, I probably won't choose it, because it will become too heavy to support the lens with two or three.

I believe that the consumer flagship will become a widely accepted product in a few years. With the improvement of EVF quality and the expansion of image buffer, its advantages such as appropriate size, light weight, low comprehensive cost, real-time histogram and quiet shooting will win more converts. At present, Minolta A2 has done the best in this respect, which has improved the shortcomings of many traditional consumption flagships.

In a word, the two cameras have their own advantages and characteristics in function. Which of these two cameras should I buy? The most important thing is to look at your needs. If you are an ordinary user, because you don't have a high demand for professional shooting, you might as well buy an 8 megapixel quasi-professional digital, which is relatively low in price, richer in functions and lighter in portability. If it involves business and professional needs and requires high image quality, buy a popular digital SLR. Digital SLR camera is a huge system, and the consumer flagship is usually just a camera. Compared with choosing consumer digital cameras, users who choose digital SLR cameras should make a comprehensive plan for the focal length, filter, flash and original body of the lens from the perspective of building a photographic system.