SLR, short for single-lens reflex, is a type of camera that contains an internal reflex mirror that allows users to look through the optical viewfinder to see what the lens sees and what will be captured when a photograph is taken. When the shutter button is pressed, the camera captures the image by flipping the mirror out of the way and allowing the light to pass through to the light receptor.
SLR vs. DSLR cameras
The main difference between these two types of cameras is that the SLR captures images on film and the DSLR (digital single-lens reflex camera) captures images digitally. On its LCD screen, DSLRs can also display a digital live viewing of the viewfinder as well as allow you to view pictures that have already been taken. While the SLR stores its images on film, the DSLR stores its images on a memory card. Another feature that the digital camera offers is the ability to record video.
Some similarities between the two include the use of a mirror within the camera and the ability to use multiple lenses on one camera body.
Are SLRs obsolete?
With the advance of digital photography, only professional photographers or camera hobbyists continue to use SLR film cameras. There are more DSLR cameras on the market, and many film enthusiasts have resorted to buying vintage SLR cameras. Professional-grade film cameras are known for being able to capture better quality, higher resolution images than their more convenient digital counterparts. Because of this, SLR film cameras are not completely obsolete but are less frequently used by the average consumer.