DSLR

A digital single lens reflex or DSLR camera is a single-lens reflex camera (SLR) which records images using electronic sensor instead of film. Like SLRs, DSLRs are often used by professional photographers and advanced amateurs.

DSLR accepts interchangeable lenses and accessories such as flash units, and accessories for SLRs are usually compatible with DSLRs of the same brand. When aiming a DSLR, the photographer is looking through the lens (unlike a rangefinder camera or a camera with a separate viewfinder) and the image is projected optically (unlike a camera with an electronic viewfinder).

The imaging sensor in a DSLR is typically much larger than the one in a standard digital camera. Larger sensor allows better image quality, shallower depth of field and wider field of view. However, the sensor is usually smaller than a frame of 135 film. The average size of a typical DSLR sensor being about 22 mm x 15 mm, or the size of an APS film frame. If this is not the case and the sensor is the same size as the equivalent frame of film (usually 35 mm wide), the camera is said to have a full-frame sensor. Currently (2005) only some expensive professional DSLRs have full-frame sensors (typically 36 mm x 24 mm). One example of a full-frame DSLR is the Canon EOS-1Ds Mark II.

Depending on the position of the reflex mirror, the light from the scene can only reach either the eyepiece or the sensor. Also, a mechanical shutter is used to control the exposure. Therefore even though a DSLR has a color display at the back of the camera body, it doesn't provide "live preview" (allowing focusing and framing using the display). The only exception to this rule so far is Canon EOS 20Da, a Japanese variant of Canon EOS 20D designed for astrophotography.

Camera manufacturers expect that professionals and advanced amateurs continue to prefer DSLRs over other forms of digitals cameras. However, if electronic viewfinders with near-zero lag and very low energy consumption are introduced, non-SLR cameras may become a viable choice for a large number of people who now need SLRs.

Many medium format SLRs can accept a digital camera back to turn the camera into a kind of DSLR with very high image quality. However, the combination is very expensive and bulky, and thus they are rarely used outside fashion photography and portraiture.

Digital SLR versus Digital compacts

What is the edge of Digital SLRs over non-SLR digital cameras?Non-SLR digitals are of 2 types.Digital compacts and SLR-like compacts(eg:Minolta DimageZ2, Nikon 5700),the latter type having lenses with large zoom capacity(10x-12x) which even vies some DSLRs.

In the conventional Film photography, SLR's biggest advantage over Rangefinders is the TTL(Through The Lens) viewing of the object of desire. In Rangefinders frame is seen via a prism, not through the focusing lens. However, the high-end non-SLR digitals (like the Nikon 5700), also offer TTL viewing through the focusing lens, projected onto its LCD screen. But, the image in the viewfinder of such non-SLR digitals are not TTL and suffers the same aberration (what you shoot is not exactly what you see) as that of conventional film rangefinders. Entry level compact digital cameras offer only the viewfinder viewing. Thus, the DSLRs can show you the exact frame in both viewfinder and LCD screen. DSLRs also allows for easy lens interchanges, which is not available in any non-SLR digitals. (High end rangefinder cameras of conventional Film photography allows lens interchange)

The bottom line is that, DSLRs combine all the plus points of both film and digital photography. The cons are the bulk of the equipment and cost.

See also

• digital photography