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Is a Camera an Optical Instrument?

Broadly speaking, an optical instrument is a device you use to process light to permit or enhance viewing. Familiar examples include spectacles, telescopes and microscopes. Under this definition, a camera is a type of optical instrument, since it processes light, focusing it through a very small aperture and onto a surface to create an image.

Optical Instruments
- You can use an optical instrument to magnify tiny or distant subjects, allowing you to see over greater distances or view fine details. Some optical instruments let you see into parts of the electromagnetic spectrum that are normally invisible to human eyes, such as ultraviolet and infrared. In the case of cameras, you use them to process light to create visible images.
Camera Obscura
- The camera obscura was used to observe and record sunspots.
  
  A camera works by focusing light waves onto a surface, producing an image. In the case of the camera obscura -- literally "dark room" -- the light waves enter a dark room through a very small aperture and are projected onto the opposite wall, producing an inverted image of the scene outside. You can use a camera obscura to create art by hanging a canvas or paper on the wall where the image is projected and drawing or painting over the image. Before modern cameras, the camera obscura was used to make detailed drawings of landscapes and even astronomical phenomena.
Camera Lucida
- Like the camera obscura, you can use the camera lucida to help make accurate drawings. The camera lucida doesn't project views onto a drawing surface; instead, you look into it and see a reflected image of the subject superimposed on the drawing surface by means of a two-way mirror. This helps you to capture perspective more accurately in your drawings. The camera lucida's name means light room, a reference to the fact that it doesn't involve a darkened chamber; you can use the camera lucida outdoors.
Modern Cameras
- Modern cameras capture a permanent record of the image entering the aperture, either using a chemically-treated substrate, as in the case of film cameras, or an array of light receptors that turn the image into electronic data, as in the case of digital cameras. Not only can you create a permanent image of things that are normally visible using a camera, but you can use photography to visualize things that are normally difficult to see. An example of this would be a photo-finish, when the result of a race or other competitive sporting event is too close, and over too rapidly, to judge accurately.

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