The hottest thing in the digital camera market is, without doubt, the digital SLR, which is better known as a digital SLR. While dSLR fly the shelves of a dealer, many new users are confused about the terminology. Many people know that SLR stands for Single Lens Reflex ". Like almost everyone accepts SLR interchangeable lenses, it seems that it should be known as multi-lens reflex (MLR) cameras.
If you want to see how the EPE has been called, you must immerse yourself in the history of the camera. First cameras were similar view of the cameras used today. The photographer looked through the lens, focused, integrated and then a main course is located behind the film optical image. Although the process was crude by modern standards, the photographer enjoyed a great control as he looked straight through the lens of the true image to compose the shot.
While this was good for still life, portraits and landscapes, this process does not lend itself to action photography. These early cameras could record only one image at a time. And that's why you've never seen a motor view of the camera.
Aware of the need to provide sequences of exposures, camera manufacturers are beginning to experiment with different designs of the film. With a roll of film in the camera, the photographer can take many pictures without having to recharge. Although this improved performance dramatically, causing another problem. The roll of film had to pass close behind the lens of the camera, which means that the photographer could not look through the lens of the camera to compose and focus.
Rangefinder cameras seem to keep things in focus
The low-end consumer camera roll film is generally used a cheap "fixed focus" lens, then a simple display was enough. The best optical quality, however, require the lens to focus, and because the photographer could not look through the lens with a roll of film, this is a big problem. One of the first solutions to this problem was the range finder – a type of camera that offers a distance measuring scale in the viewfinder. In determining the range of the viewfinder, the photographer can adjust the focus to match – usually with good results.
Twin Lens Reflex cameras offer another solution
While rangefinder type cameras worked well, the camera industry is constantly evolving. A second method that allows the photographer to focus and compose appeared in the Twin "-Lens Reflex" cameras. These cameras use two identical lenses arranged one above the other in the form of an up-and-under shotgun. Winds film down over the target, while the photographer can zoom through the lens higher. The dual-lens cameras were too bulky, so the designers have added a mirror and frosted glass to the top of the camera, hence the term "reflex.
Now you can keep the camera at the level of life and looks down on the frosted glass to preview the image through the mirror behind the lens higher. When the user sets the focus on the objective above, an exchange rate mechanism drives the bottom "taking lens" per game.
Meanwhile two rangefinders and reflex cameras offer a credible way to focus and to preview a shot, and allowed the photographer to look through the lens really real. The exact composition is sometimes difficult.
SLR cameras to take another step forward
In his search to allow users to see through the real "seizure" of the lens, the camera manufacturers turned to the periscope – a simple device with two mirrors at angles to bend the light path. Periscopes are easy to understand – every child can build one of a pair of mirrors and a few pieces of wood.
In a camera, the bottom of the mirror is placed in a 45 degree angle directly behind the goal. Light striking the mirror is projected onto a frosted glass top. While a second mirror that shows the image on the glass floor to the user, which does not seem fair, because the mirrors tend to change things. So the designers of the camera added a prism arrangement which corrects the inverted image. When looking through the viewfinder of a DSLR, looking through a prism, displaying the image on a frosted glass, which displays the image on the mirror behind the lens.
Only one problem. If you were careful, you are no doubt noticed that the blocks below reflect the light path to the film (or digital sensor, as the case may be.) Now, the photographer can see if the lens but the image can be projected to filmplane.
So the designers of the camera had to add another wrinkle. Took the mirror. Just long enough to make a presentation, because when the mirror moves, the photographer could not see anything through the lens. So he designed the return "immediate" mirror. At the time of exposure, flies up to the mirror, fire shutter and the mirror bounces down. This is an incredible feat, considering that the immediate return mirrors have to flip back and forth in a heartbeat, and again for the life of the camera.
Once perfected the mirror immediate return, photographers can once again the layout of your pictures look through the lens. Unlike the twin lens reflex camera this new class just need a lens to focus and shoot. So that became known as … you guessed it … Single-Lens Reflex.