DSLR: What does Digital Single Lens Reflex mean?
DSLR stands for Digital Single Lens Reflex. Before digital cameras, SLR (without the D) was a common design for cameras. Then when digital cameras came along, the DSLR adopted the same basic design but replaced film with a digital sensor.
The DSLR having a single lens means the optical viewfinder and the sensor share the same lens. This allows the photographer to peer through the camera and see exactly what it will capture. The ‘reflex’ refers to the mechanism that allows the light path to swap between the viewfinder and sensor upon photo capture.
Smartphone and mirrorless cameras differ from this as their screen or viewfinder projects a digital image of the scene. While the view of the scene is accurate, the users are not actually looking through the camera lens.
How the DSLR camera works
First, light enters the camera through the lens. Here, light rays pass through several elements and focus it towards the sensor or viewfinder.
While image capture is not taking place, a mirror located after the lens reflects the light upwards at 90 degrees and stops it from reaching the sensor. From there, the light enters the pentaprism which reflects the light two more times to direct it out the viewfinder. Because the lens inverts the image, the pentaprism re-inverts it from left to right to ensure the viewer sees the scene unmirrored. The lens also flips the image upside down, but the mirror corrects this.
Once the photographer has lined up her shot, she pushes the shutter button. This flips the mirror out of the light’s path and gives the light a direct line of sight to the sensor. The shutter also opens at this point to reveal the sensor. During this, the focussed light hits the sensor which gathers the light info to capture the shot.
What are the advantages of the DSLR camera?
Many say the DSLR camera’s days are numbered with the increasing popularity of mirrorless cameras.
However, I believe the DSLR will be around for a long time. Much like the vinyl record, affetionardos will continue to promote the DSLR. There’s a certain charm about the optical viewfinder. Being able to see the actual light of the moment in time you are immortalizing makes for a more genuine experience.
The lens selection available for DSLR cameras is also huge. I would argue the choice of lens is the most important factor in taking amazing photos. Portrait, landscape, and wildlife photography all require different lenses to frame perfectly. Therefore, with so many lens options to pick from, the DSLR is still my camera of choice.
