Question: how do cameras take pictures

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  1. Hi Papasmurf,

    Regardless of whether the camera is a film or digital camera, they work in similar ways.

    Cameras consist of three parts, the optical part – the lens, the image storage part – film or a semiconductor array, and the image capture part – the camera body.

    When you point the camera at something, the lens focuses the light onto an area where the film or semiconductor array is, and when you press the GO PICTURE button, the shutter opens and shuts very quickly letting light through.

    In a film camera, the light causes a reaction on the film and later on is developed via a chemical reaction. In a digital camera, the light is detected on an array of semiconductors that turn that information into digital data and are stored.

    One of the cool things with cameras, is that they actually see a lot of better than our eyes in that they pick up broader areas of the light spectrum. You can test this. If you have a video camera, or an iphone will also work, get your tv remote and point it at the camera and press and hold down a button. You will notice when you look at the control you cannot see anything, but when you look at the image on the camera, there should be a little light flashing which is the infrared beam. Pretty cool.


  2. Hi papasmurf,
    Nice question, and Dustin has done a very good job of explaining how cameras work. 🙂

    Our eyes actually work like this as well – light comes in to the eye through a hole called a pupil (the dark bit in the middle of your eye) and hits a lens in the front part of the eyeball. The light is then focused through the lens like in the camera, and the image is formed on our retina (in the back part of the eyeball), like the film of semiconductor array in a camera. The information then gets passed through our optic nerves to the our brain, and then we see! One thing I find really cool is that the image that is formed on our retina is actually upside down to what we are actually seeing (because of the way the light goes through the lens), and then the brain processes the information and turns the image the right way up for us!

    Have you ever noticed that someone’s pupils have changed size? When we are in good light, our pupils are not very big because plenty of light can get through them already, but if we are in a darker environment, our pupils dilate (become bigger) so that they can let more light into our eyes so that we can still see.


  3. Great answers Dustin and Arti