A single-lens reflex camera (SLR) is a camera that uses a mirror and prism system to allow the photographer to view through the lens and see exactly what will be captured. The mirror reflects the image from the lens up to the prism, which then reflects the image to the viewfinder. This system allows for precise focusing and framing of the image. SLRs were the most advanced photographic preview system available until the development of digital imaging technology with an on-camera live LCD preview screen. However, SLRs are still popular in high-end and professional cameras because they are system cameras with interchangeable parts, allowing customization. They also have far less shutter lag, allowing photographs to be timed more precisely.
SLRs can be either film or digital cameras. The “D” in DSLR stands for “digital,” and it was added following the development of SLRs with digital sensors. The most significant difference between SLRs and DSLRs is their sensor. DSLRs capture the image digitally, on a memory card, while SLRs use a film made of plastic, gelatin, and other material to record the image. DSLRs also have LCD viewfinders, like in point-and-shoot digital cameras, which is handy for situations when an optical viewfinder cannot be used.
SLRs have the unique feature of truly interchangeable lenses. Because the mirror inside the camera hides film from light, you can change lenses even when a roll of film is in the back of the camera. Most SLRs also have built-in light meters to measure light for a good exposure, eliminating the need for additional handheld light meters. However, once the mirror flips up to expose the film, the photographer’s view is blocked, which could come into play for portrait photography or motion photography, among other techniques.
In summary, SLRs are cameras that use a mirror and prism system to allow the photographer to view through the lens and see exactly what will be captured. They are popular in high-end and professional cameras because they are system cameras with interchangeable parts, allowing customization, and have far less shutter lag, allowing photographs to be timed more precisely. SLRs can be either film or digital cameras, and they have the unique feature of truly interchangeable lenses.
