Photography for Beginners - How Does A Camera Work?

The story of the camera started with Ibn al-haytham, the father of ophthalmlogy. He was a scientist, mathematician, and a doctor from golden age of muslim civilization. He was a keen observer. From his experiments, he explained that light travelled in a straight line, and he proved it by projecting an image to a surface through a small hole in a darkroom. He also used his experiments to explain how the human eye works. Ibn al-haytham's darkroom was later called Camera Obscura. His work on eyes and images laid the foundation for modern day cameras. This includes both video cameras and still cameras. Let's have a look at your camera to understand some basic concepts on how camera works. Your camera is a darkroom that has a hole in front of it, the hole allows the light to come into the darkroom. The light enters the hole in a straight line and gets projected on the wall of the dark room. When taking photos, a photographer wants to control the amount of light coming in to the camera and he wants a sharp focused image. This design lacks both. Let's introduce a lens in our camera design. Lens is mounted or placed in front of the camera hole. As part of the design, a lens manufacturer can have one or a series of lenses to make it work. A lens helps us control the light entering the camera. It focuses the light on a specific area within the dark room. To capture the image of this light falling on the surface of the camera, we insert a medium that is sensitive to light. In the old days, this used to be film, but most modern camera have digital sensors. The light coming in through the lens thus falls on the medium, and we save it. In the digital cameras, the sensitivity of the medium can be adjusted via the ISO settings. Now that we are able to focus light on the medium more accurately, we need to have more control on the light. For that, let's look at how human eye works. During day time, when there is bright light around us, the iris muscle of our eye constricts to prevent excessive light from entering the eye. At night time, or in low light conditions, the iris dilates to allow more light to come in for more visibility. Let's have a look at how we can control the amount of light coming into the camera. In our design, we need something that can contract and expand like a human eye. An aperture is an opening through which light travels, and in a camera, it needs to be able to contract and expand to allow less or more light to enter. Aperture is installed inside the camera lens. So, not only your image is focused by the lens, but the amount of light is also controlled by the aperture of your camera. You can control the aperture in f-stops using the aperture priority mode in the camera. Let's see how we can stop the light from falling on the medium all the time. You only want the camera to take the photo when you press the button, don't you? A shutter is a device the allows the light to pass for a determined period of time for the purpose of exposing the film or the digital sensor. A shutter is installed inside the camera. It is like a door that stops the light. it only opens when you press the button on your camera to take a photo. Once the camera has finished taking the photo, the shutter closes. You can control the shutter speed in second using the shutter priority mode in the camera. As a photographer, you need to view and compose your shot before you take it. Inside the camera is a mirror that is placed in front of the medium. When you press the button to take a photo, the mirror flips up to allow the light to travel towards the medium. But when the mirror is closed, it bounces the light into a prism and then light goes out through an opening called a viewfinder. This is how you are able to view the scene in front of you. Let's summarise and review what we have learnt in this tutorial.. your camera has a medium to capture the light.Medium can be film or digital sensor. the lens of the camera focuses light on the medium. aperture of the lens controls the amount of light coming in your camera. the shutter opens for a predetermined period of time to allow the light to fall on the medium. and the mirror allows you to see through the viewfinder. How do I take good photos is a very common question. aside for developing an eye for lovely compositions, the secret recipe for good photography is learning the art of aperture, shutter and the ISO. Watch Mujahid photography tutorials on aperture shutter and iso to learn more.