digital single lens reflex (DSLR)
SLR cameras are high-quality cameras with interchangeable lenses. This type of camera is divided into single- lens reflex(SLR) cameras and twin-lens reflex (TLR) cameras.
In the case of single-lens cameras, the object is viewed via the single-lens system with the downstream mirror and prism system. As a result, the way of looking at the object and the angle of view before taking the picture correspond to those of the later photo. In addition, one can choose between various high-quality lenses with all possible focal lengths and shutter speeds. The exposure metering is also done through the lens. This is called Through The Lens( TTL). With TTL metering, the set focal length is also taken into account.
In general, there is the same difference between a film SLR and a digital SLR (DSLR) as there is between a conventional camera and a digital camera. The digital versions use light-sensitive image sensors, CCD sensors or CMOS sensors, which convert the incident image into a charged image. The resolution of the image sensors is well above 10 megapixels and in some cases even exceeds 20 megapixels( MP). The image information is displayed on more or less large and high-resolution displays on the back of the camera.
When shooting with a digital SLR camera, the oscillating mirror in the camera flips up and the optical channel to the CMOS sensor is opened for the shutter opening time. The charge image is loaded from the CMOS sensor to the working memory and from there to the memory card. Before saving, the color photos are compressed with JPEG. Compact Flash( CF) cards, Secure Digital( SD) cards and MiniDiscs ( MD) are used as memory cards. The extremely fast XQD cards and CFast memory cards are available for fast storage of large image data and series of images at up to ten frames per second.
With the FourThirds concept, Olympus has developed an open camera standard that enables more compact camera designs.