What Is an SLR Camera?

July 10, 2014 Photography, General 0 Comments

Harrington What Is an SLR CameraDespite the incredible advances in camera technology in recent years, the SLR remains the standard for professional photography. An acronym for single-lens reflex, SLR refers to the way the image is created in the viewfinder. Below we discuss what an SLR camera is in more detail, and how it differs from other cameras.

What Is an SLR Camera?

As light enters the lens of an SLR camera, it hits a prism and mirror, which redirect the light up into a viewfinder so you can see exactly what you are shooting. When you press the shutter release, the mirror flips up out of the way, allowing light to reach the film or sensor. This method of delivering light to the viewfinder provides exactly the same image that will be received by the camera, instantly (well, at the speed of light).

Single-Lens Reflex and Twin-Lens Reflex

Before the single-lens reflex system became popular in the 1960s, most cameras had two optical paths for light: one to the film (or other light-sensitive material) and one to the photographer's eye. This was known as twin-lens reflex (TLR), and it provided the photographer with a fairly accurate approximation of the photo being captured. The variance was almost unnoticeable for medium- to long-range photographs, but for close-ups, the difference in perspective made it very difficult to properly focus and frame shots.

The Modern Digital SLR Versus Alternative Cameras

Today, TLRs are almost nonexistent, and film SLRs have been largely replaced by digital (DSLRs). The DSLR functions much like the traditional models by providing an optical viewfinder showing the same image as captured through the lens. Similarly, most other alternatives — compact digital camera, mirrorless interchangeable lenses and phone cameras — rely on a digital viewfinder and show you the image from the light that is actually entering the lens, with the exact same perspective.

The digital technology going into modern photography is becoming incredibly advanced, but the best cameras still perform best with classic optical lenses, prisms, mirrors and viewfinders.

Photo credit: Flickr


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