Digital SLR Cameras

The word DSLR (digital slr cameras) stands for digital single-lens reflex cameras, which are still image cameras that utilize a single lens reflex mechanism to direct light from the lens to an optical viewfinder on the camera. Canon, Nikon, Sony, Pentax, Olympus and several other companies make digital SLR cameras product.

Digital SLR evolved in the early 1990s, but became extremely popular in the 21st century. How a DSLR operates is as follows: there is a mirror reflection of the light going through the lens upward at a 90 degree angle. It is then reflected in the roof pentaprism for three times, adjusting it for the photographer’s eye. During the time of exposure, the mirror assembly vacillates upward, the size of aperture reduces, and a shutter opens to let the lens to project light to the image sensor. The image sensor is then covered by a second shutter, the mirror returns to the 45 degree angle while the shutter resets for the next exposure.

Compared to the popular consumer digital cameras, digital SLR cameras products have different optical properties, for example, the majority of DSLR use optical viewfinder (OVF) framing for shooting sharp and stable pictures, and recent models even add auxiliary electronic viewfinder.

Many DSLRs now employ CMOS (complementary metal–oxide–semiconductor) image sensor which is a device that converts an optical image to an electrical signal using a CMOS manufacturing technology. One of the advantages of CMOS image sensors over CCD image sensor is that the cost of CMOS sensors is relatively low. CMOS image sensors are produced by means of an ordinary CMOS process, resulting in low power consumption and low voltages. A CMOS image sensor is characterized by high quantum efficiency, high dynamic range, low read noise and random access, and it is fully compatible with the manufacturing for a CMOS device.

Most DSLRs features a number of scene modes including Portrait, Landscape, Sports, Night portrait which are already enough for an interchangeable-lens camera. The majority of these scene modes enable users who do not want to bother with shutter speeds, ISO settings to take a great shot based on what photo they want to take.

If you have interest in other digital products, please also take a look at our compact digital camera, digital camcorders and lens.

Category: Canon EOS  Leica M   Nikon D  Olympus E   Panasonic G  Pentax K  Sony Alpha  Sony NEX