Digital Cameras 2U

Digital single-lens reflex camera

DSLRs are conceived for professional photographers and are well adapted for action photography or specialized uses. They are based on film single-lens reflex cameras and retain their main features : image composing done through the optical viewfinder using a mirror reflected image and exchangeable lenses, albeit a few early SLR digital cameras like the Olympus E-10 have a fixed lens.

The ability to change lenses gives the same benefits as in film cameras, allowing tailoring a lens to an intended use instead of a compromise. They can use the same lenses as their film counterparts, but the sensor is usually smaller than that of 35 mm film. A common term is “APS class,” being the same general size as APS film. Focusing on the smaller area results in digital cameras having a zoom of 1.5 to 2.0 times over the same lens on a 35 mm film camera. Thus a 50 mm lens on a DLSR with a 1.5 crop ratio would show the same angle of view as a 75 mm lens on a 35 mm camera.

DSLR cameras have larger image sensors than compacts or prosumers, and thus higher sensitivity in dim lighting and less noise overall in the pictures they take. They usually are instantly on and the autofocus and operation is faster. Most of them can save in JPEG and raw formats even simultaneously.

They are bulkier, heavier and frequently much more expensive. Two characteristics many consumers are surprised to find due to the reflex viewfinder is they cannot record movies and the screen is only for reviewing pictures. All composing is done through the optical viewfinder which has more resolution than an electronic viewfinder and does not produce any delay. In 2006 the Olympus E-330 is the only DSLR that can use the LCD for a live preview, and will be joined by the Panasonic Lumix DMC-L1.