Modern cameras still follow pretty much the same basic principle for capturing images as the earliest camera dating as far back as the 1800s. Cameras still have a light-sensitive area inside a dark chamber and a hole that allows light to enter. But the cameras that we use today are much more complicated machines than their earlier counterparts.
What was once little more than a simple box containing a piece of paper coated in light-reactive silver compounds has evolved into a complex mix of mechanical and digital systems giving photographers much more control and flexibility to capture the world around them than these early photographic pioneers likely could have ever dreamed about.
How Does a DSLR Camera Work:
The Physical Elements
The basic mechanical functioning of modern DSLR cameras is surprisingly similar to classic film SLR cameras.
DSLR cameras, which stands for digital single-lens reflex, are made up of a body and a lens which is attached to the camera via a system that allows for swapping different lenses based on the needs of the photographer.
What’s Inside the DSLR Body
The body of a DSLR camera contains the sensor, the shutter, and the viewfinder, as well as the controls and the locking mechanism for attaching the lens.
The sensor is found inside the camera body, placed behind the shutter or curtain. In front of the shutter is a mirror that reflects the light coming into the camera through the lens and into the viewfinder above, allowing the photographer to see almost exactly the same image that would be captured by the sensor.
When a photograph is taken, the mirror rotates up, out of the way of the sensor. Simultaneously, the shutter slides open, allowing light to hit the sensor for the appropriate amount of time, based on the camera settings.
Once the time designated by the shutter speed setting has passed, the process is reversed. The shutter once again closes to cover the sensor, and the mirror drops down to allow the photographer to use the viewfinder once again.
What’s Inside the Lenses
The lens, which directs light into the camera and onto the sensor, is made up of a series of optical elements, or shaped pieces of glass which bend the light coming into the camera in specific ways in order to achieve the desired focal length.
Modern lenses also contain what is known as a diaphragm, which is a series of blades arranged in a circular pattern to create a circular hole in the center. This diaphragm is what allows the photographer to adjust the aperture of the camera.
In addition to this, lenses designed for modern DSLR cameras also have mechanical elements inside that allow the photographer to adjust the focus and the focal length by moving the internal optical elements, changing the way the light bends before hitting the sensor.
How Does a DSLR Camera Work:
The Digital Elements
With the rise of digital technologies over the past several decades, camera technology has seen unprecedented progress. The creation of digital sensors, systems for calculating settings to achieve proper exposure, and the addition of digital screens and interfaces has led to a revolution in how cameras work and how photographers can capture images.
A Digital Sensor Replaces Film
The single most revolutionary feature of digital cameras, such as DSLRs, and what sets them apart from all previous types of cameras, is the inclusion of a digital sensor, replacing physical media such as film.
Whereas the film used in many modern cameras is created by placing a light-sensitive compound on a sheet of plastic, digital camera sensors use light-sensitive photoreceptors to translate physical signals received as photons from the light into digital representations known as pixels inside the camera.
The change from physical media to digital sensors has allowed photographers to shoot with much more freedom. Even the earliest digital cameras could hold many more photographs than the 24 or 36 shots that a typical roll of film might allow.
An Interactive Interface & Advanced Settings
The switch from film to digital has opened up a whole world of new opportunities for interacting with your camera and controlling how the camera captures an image.
The most visible element of the digital interface available in most DSLR cameras is the large digital screen found on the back that allows us to review and manipulate the images the instant the camera has finished recording it—no more waiting until you get back to the darkroom to realize that gramma is blinking in that lovely family portrait!
But a nice way to review the photos isn’t the only trick DSLR’s have up their sleeve. Digital cameras now offer features that make previously complicated photography techniques incredibly simple.
Want to take multiple exposures of a single subject to create an image with an increased dynamic range? With automatic bracketing, it’s a breeze. Many cameras even allow you to set an interval timer and take multiple photographs at intervals you choose, making it easy to create time-lapse videos or compilations.
Modern DSLRs have tons of settings designed to give you more control than ever, making complicated or time-consuming techniques easier, so you can focus on capturing the best shot instead of micromanaging your camera equipment
Your DSLR camera may be brimming with complex digital technology and the most advanced mechanical features. However, when you pull away the fancy bells and whistles, it still works in much the same way as the first cameras did nearly 200 years ago.
While these new technologies and advanced sensors are included to help make your life easier as a photographer, the fact that the basics of camera functionality have stayed relatively steady over the years just is further proof that, if these early photographers could capture breathtaking photos with little more than a box with a hole in it, then even if you have an entry-level, budget DSLR you can still take amazing photographs, too.