In this system, the unique design of the mirror and prism enables the photographer to directly observe the image passing through the lens from the viewfinder. It can be seen from the structural diagram of a single-lens reflex camera that the light passes through the lens and reaches the reflector, and then refracts to the focusing screen above to form an image. Through the eyepiece and pentaprism, we can see the scenery outside in the observation window. When shooting, press the shutter button, the reflector will pop up, and the shutter curtain in front of the film will be opened at the same time. The light (image) passing through the lens will be projected on the film to make the film sensitive, and then the reflector will immediately return to its original state, and the image can be seen in the viewfinder. This structure of the single-lens reflex camera ensures that it is shot through the lens, so that the image seen in the observation window is always consistent with the image on the film, and its framing range is basically consistent with the actual shooting range, eliminating the parallax phenomenon of the paraxial head-up framing camera. From the perspective of learning photography, it is very conducive to intuitive framing and composition.
Because the whole imaging system of SLR (focusing and shooting) is a lens, there is no parallax, that is, the framing and imaging are the same. (Traditional cameras are mostly paraxial cameras. Secondly, because the imaging system is used as the lens, the coordinated response is faster than that of ordinary cameras, so the SLR camera can better shoot high-speed moving objects (it will not miss the beautiful scenery because of the slow response of the camera). Thirdly, SLR cameras use lens transformation to form different photography systems. For example, you can change wide-angle lenses, lengthen lenses, add color films and choose macro lenses to meet your different needs. You won't miss the beautiful scenery because the camera lens is limited.
Finally, because SLR cameras mostly use pure natural crystal or fluorite polished lenses, the price is much more expensive than ordinary glass and plastic lenses. Some even use ultrasonic motors to adjust the lens, the vibration IS smaller than mechanical ones, and some have their own anti-shake patents (for example, Canon's EF series lenses have IS logo), especially the so-called pure natural fluorite lenses with red lines. A lens is between 30,000 and 50,000 yuan.
DSLR digital camera refers to a single-lens reflex digital camera, that is, digital, single-lens, lens and reflex. Representative models in the market are common in Nikon, Sony, Canon, Pentax, Fuji and so on. This kind of camera is usually big and heavy.
Models that use electronic viewfinder EVF are also classified as SLR, but generally "similar" is added or EVF framing is indicated, such as Olympus C-2 100UZ and Fuji Finepix 6900. In the working system of SLR digital camera, after the light reaches the reflector through the lens, it refracts to the focusing screen above to form an image. Through the eyepiece and pentaprism, we can see the scenery outside in the observation window. In contrast, ordinary digital cameras can only see the captured images through the LCD screen or electronic viewfinder (EVF). Obviously, the directly seen image is more conducive to shooting than the processed image.
A major feature of SLR digital cameras is that they can change lenses of different specifications, which is an inherent advantage of SLR cameras and incomparable to ordinary digital cameras.
CMOS sensor In addition, SLR digital cameras are now positioned as high-end products in digital cameras, so the area of photosensitive elements (CCD or CMOS) related to the photographic quality of digital cameras is much larger than that of ordinary digital cameras, which makes the photosensitive area of each pixel of SLR digital cameras much larger than that of ordinary digital cameras, so each pixel can show more detailed brightness and color range, which makes the photographic quality of SLR digital cameras significantly higher than that of ordinary digital cameras.
Simply put, SLR digital cameras are not suitable for any users. First of all, it is one thing to have the necessary professional knowledge. Secondly, to make good use of SLR digital cameras, we must match different types of lenses, which is likely to make the cost of lenses higher than the cost of buying digital cameras.
Moreover, when traveling abroad, the weight of camera bag with lens group is much higher than that of ordinary camera, which will become a serious burden in the travel process. In addition, when changing the lens of SLR digital camera, the photosensitive element will be directly exposed to the air, so we must also pay attention to the maintenance of the camera when using it. Therefore, although the shooting quality of SLR digital cameras is higher and the price has dropped a lot now, it is not suitable for all users, and users should choose according to their own needs when purchasing.