What is a SLR Camera?

The single-lens reflex, known on the market as the SLR camera, is one of the most popular digital cameras in the world. It uses a movable mirror placed between the lens and film to transmit the image through projection to the focusing screen. The use of a pentaprism allows you to see the image via the viewfinder or add other accessories to view the image in a different light.

The SLR utilizes a focal-plane shutter which sits in front of the focal plane. Some models do not set up their SLR cameras like this and additional devices are used to ensure that light does not reach the film between exposure. Shutter blinds, such as those used in the Hasselblad models, keep light out between exposures. This is beneficial in situations where too much light might be a problem for your shots.

SLRs are built based on the following design: Lens, mirror, shutter, film or sensor matrix, focusing screen, condensding lens, pentaprism and the viewfinder. These are typical of most SLR models and vary depending on the brand and model. Basically, when you take a picture, the light passes through the lens is reflected by the mirror and then transmitted onto the focusing screen. From there, the condensing lens and internal pentaprism reflects the image as it appears in the viewfinder. When you take the picture, the mirror structure moves, the focal plane shutter expands open and then the image is taken and presented onto either film or a set of sensors in the inner workings of the camera as you see it in the viewfinder.

The SLR was developed in the late 1800s. Exakta introduced the first 35 mm SLR during World War II. They included waist-level viewfinders and were influential for taking some of the most well-known shots of the time throughout Europe and the front lines. Eye-level viewfinders were introduced in Hungary in the 1940s by Jeno Dulovits. It also utilized the first instant-return type mirror to see what you were taking at the time it was being taken.

Light metering, from a process known as through-the-lens, came in the 1960s. The Topcon RE Super and the Pentax Spotmatic utilized that technology. Auto-exposure came in Savoyflex cameras in 1965. With the introduction of miniaturization of computer and electrical components in the 1960s, SLR cameras became smaller and smaller, as did most technological devices during the time.

The idea of auto-focus came through Pentax's ME-F SLR camera. Minolta's Maxxum 7000, introduced in 1985, used a motorized auto-focus system that also allowed you to advance film through the use of a winder. Since the auto-rewind had already been created, being able to skip ahead was a new advance for SLR and cameras in general. Light metering, especially electronically, developed throughout the 1980s and into the mid-90s. Most companies had to completely scrap their camera designs to rework how to integrate the auto-focus concept into working models.

User interfaces and viewfinders were the next parts of the SLR camera to be developed and reconfigured. LCD displays replaced LED displays allowing for a crisper view of what was being taken. Wheels, buttons and easier click-wheels replaced point-and-shoot stereotypes on most cameras. This made it easier for photographers to change settings, take pictures and change set-ups if needed. Even anti-shake features were introduced to reduce the need for a steady hand and a tripod.

Canon, Nikon and Samsung in particular began developing digital SLRs as early as 2000. Pentax, Minolta and Sony also began introducing SLR models in recent years but continued to work the technology before that. SLR cameras now come in film or digital models, but the digital SLR has taken over the market as one of the premiere types of cameras to own even for the novice photographer.

Film SLR cameras still rely on 35 mm film but still produce crisp and sharp images like their digital counterparts. Digital SLRs use memory cards and some even have built-in hard drive space to store photos. Depending on the digital SLR, you may use one or more types of memory to store your images.

The most common features of a SLR camera include through-the-lens metering, enhanced flash control and anti-shake options. The flash in particular is one of the pros of owning a SLR digital camera, as the flash can be pre-determined to send out a single burst or multiple bursts depending on the shot you are taking and the light you need. Many camera models will actually measure the light in the lens itself and automatically close the shutter when the image has been exposed to capacity.

A SLR digital camera is one of the easiest ways for any photographer to take great pictures. They are affordable for any price range, come with many different features and are easy to learn how to use through instruction manuals and tutorials. Owning a SLR digital camera will allow you the flexibility to take pictures anywhere and have them turn out great.