A Model for Essay #1 (Winter 2007)

"A Tool of Instant Artwork"

by Hieu Tran

Pictures are an instant art. Art is appreciated for the amount of work put into it, and emotions that you feel through out your body when you see it. Would you call that picture of you eating a cheeseburger with youre face washed out and your eyes red as a red balloon art? No, you call that embarrassing and probably would never let any one see it. But those pictures of you next to your prom date or at your wedding in front of the church, that is art. Those pictures are the ones you frame and display around your home. Pictures, embarrassing or not, come from so many types of cameras; from the high tech digital camera to the disposable film camera. Cameras have evolved technologically, but the basic features of a camera and how they work are still the same.

The first camera to be invented was the camera obscura, which dates back before Aristotles time (Upton 352). It was not a small rectangular box with a circular shaft and piece of glass at the end of it. It was actually a room. A dark room completely sealed with a tiny pinhole in one wall, which allowed light to travel through. The light would create an image on the opposite wall of the pin hole (Wilgus). What a phenomenon!

Light comes through the pinhole in every direction. Depending on how far the wall is, the image will either be sharp or blurry. Lets say this image is an apple; a juicy red apple. The image is created from the light reflecting off of the apple and going through the pinhole. Since light only travels in a straight line, the image on the back wall is either blurry or sharp. If the back wall is close, the light beams going through the pinhole will hit the back wall relatively close to each other; this results in a sharp image of the apple. If the back wall is farther away, the beams will hit the wall but would be more distant relatively to each other. This will result in a blurry or out of focus image; the same is true if the wall was closer. Think it this way, an overhead projector, teachers love using in high school, has a knob that can be turned to focus the image onto the screen. Turning the knob moves the projector head up and down. What really is happening is the light table is moving back and forth. This explanation tells you have a camera focuses. Instead of a room, it is a small box. Instead of moving the back part of the camera back and forth, you have a lens attached that does the movement like the projector head. Today, most cameras automatically focus which is more convenient than manually focusing but this shows how focusing works.

How do we get photos from these cameras? Heres where the process gets a little complex, but simple to understand. There is a fun toy; you can find at any gadget store, it is a box with hundreds of pins that can move up and down. The pins are all evenly distributed and it looks flat from the top of the box. Pretend the box of pins is the film. Your hand is the object. Push your hand underneath the pins and the pins in contact with your hand will move up forming a mold of your hand. Now, not all the pins are flat as they were in the beginning. Some pins are high; some are higher, resulting in what looks like a hand made of pins. Isnt that cool? The light beams reflecting off an object going through the lens have different intensities. Film has light sensitive chemicals on it. When exposed to light it will do what the box of pins did, but it will form and image instead of forming a mold of the image. Film has sped up the picture taking rapidly. Today, it is almost instantaneously.

Instead of film, digital cameras have sensors that changes light into electrical charges. The image sensor is called a charged coupled device (CCD). The computer in the camera records the electrical charges into a media like a memory card (How). This is how a digital camera takes pictures; not too different from film cameras. So what controls the flow of light so that the film or CCD is not exposed too much; that there is no image?

Cameras have two features on them today. There is an aperture and a shutter. They both work together to control the flow of light. The aperture is like that pinhole in the camera obscura, except the aperture is able to vary in size. An example would be the frozen yogurt machine at the carnival. Opening up the valve all the way will let the frozen yogurt flow through at the fastest possible rate. If the valve was half opened then the yogurt would flow through twice the amount of time. This is what the aperture does. It controls the flow of light coming in. Since apertures take time to adjust in size it cannot be designed to close rapidly enough for film, or CCD, to get any more exposure. So the shutter will do this job for the aperture. The shutter is simply a flap or a curtain that can open all the way and close down all the way; in an extremely rapid motion. The way both aperture and shutter work together is like filling up you cars gas tank. When you put the nozzle in the gas tank and pull the trigger, you control the amount of flow gas goes into the tank. You controlling the flow is like the aperture. When the tank finally gets full, the gas pump automatically shuts off. The pump automatically cutting off is like the shutter. The correct amount of exposure is complete and the shutter closes to prevent any more exposure.

All of these features make picture taking possible. The cameras housing, the film or CCD, the lens, the aperture, and shutter are the essential features. Some added features but common are the view finder and the flash. The view finder allows you to see what the picture will look like before you take it. Not all view finders are the same. In compact point and shoot cameras, including compact digital cameras, have view finders that are above the lens. So, you are not actually seeing what you are taking a picture of. It is more like looking through a site of a rifle. The aim is not 100 percent accurate but it is so close that you do not notice the difference. An SLR camera (Single Lens Reflex Camera) has mirrors inside of the camera so you are looking through the view finder is like looking through the lens of the camera. Since indoor lighting is not enough light, the flash will allow more light to be reflected off the objects or people and then go into the camera.

So many types of cameras are out there today, you could be overwhelmed by the selection. They range in all makes and models. The compact point and shoot camera, both digital and film, are your everyday cameras which will take pictures when needed or desired. Usually, these cameras are taken to parties or for work related photos; just to give a couple of examples. Theres the professional SLR camera (Single Lens Reflex), these are the cameras used at weddings, graduation, even to hunt down Britney Spears! All these cameras work relatively the same. No matter how many types of cameras they will come out with, these basic features will all ways be present.


  1. How Digital Cameras Work. Online posting. Jun. 2006. .
  2. Upton, Barbra London, and John Upton. Photography Fourth Edition. Harper Collins Publishers, 1989.
  3. Wilgus, Jack, and Beverly Wilgus. What is a Camera Obscura? Online posting. Aug. 2004. The Magic Mirror of Life. 24 Jun. 2006 .

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Page Last Updated: 7 January 2007.