• Question: How do cameras work?

    Asked by 9roda to Andrew, Ash, Gem, Paige, SJ on 25 Jun 2012.
    • Photo: Andrew Thomas

      Andrew Thomas answered on 25 Jun 2012:

      At the front of a camera is a lens and behind the lens is a shutter. The lens focuses the light bouncing off your object onto something which can record that image. Before digital cameras came along we used film which used chemicals that changed colour when exposed to light. The shutter quickly opens and closes and light to illuminates the film, which you’d then take to your local photoshop or pharmacy to get it developed.
      The front part of a digital camera is exactly the same as a film camera, though many don’t have shutters now – like the ones on mobile phones for example – because a computer in the camera tells the digital bit to switch on and off quickly. The digital bit consists of lots of pixels which instead of causing a chemical change when light hits them, produce a tiny electrical signal that is sent to the tiny computer in the camera and turned into a picture.
      Digital cameras

    • Photo: Paige Brown

      Paige Brown answered on 25 Jun 2012:

      Awesome question!

      I see Andrew has given an excellent answer! A camera is all about LIGHT and OPTICS. A camera would certainly not work if it weren’t for light, special lenses that bend and manipulate light, and even mirrors inside the camera that you don’t see. Old cameras used light sensitive film to make pictures… when light entered the camera, it would sort of ‘burn’ the image onto the light sensitive film. Now, the picture is all about electrical signals… but the ‘stimulus’ for the camera to know what it is ‘seeing’ is still light! Better lenses make better cameras… some cameras have very long lenses to be able to see very far away, sort of light a telescope, bring a large area of light into a small space inside the camera detector. Other lenses (like the new one I want to buy with money from this competition, maybe!) act almost like magnifying glasses, taking light from a very small object (like a tiny insect) and making it bigger on the camera detector! I love the science of the very ‘small’ world, the one we don’t always see that well. I’d like to share the world of the very small with students everywhere, so I’d love to purchase a ‘macro’ lens for my camera and maybe even a microscope that I can hook up to my camera!!

    • Photo: Ashley Cadby

      Ashley Cadby answered on 1 Jul 2012:

      The cameras we use are made from lots of little buckets. Each bucket has some electrons in the bottom of it, when light hits the bucket it causes the electron to float around in the bucket (because the electron now has energy). There are lots of rows and columns of buckets and when we want to see what our image was we measure how full each bucket is, this tells us how much light hit each bucket.

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