Optical Feedback

Optical feedback is the optical equivalent of acoustic feedback. A simple example is the feedback that occurs when a loop exists between an optical input, e.g., a video camera, and an optical output, e.g., a television screen or monitor. (A simple example of optical feedback is also an image cast between mirrors.)

In the animation and the still image examples (right), light from a candle is received by a video camera, amplified and then sent by cable to a monitor projecting electron beams to a monitor screen. The image on the monitor is then captured by the video camera again, and fed back to the monitor in a continuous loop.

The original light source, in this case from the candle, can then be extinguished, while the feedback loop continues. For each loop the image is doubled and the image interferes with itself. The electronic loop moves with near light speed, but as the resulting image is projected onto the phosphor dots on the inside of the screen by the electron beam, the phosphor points take time to begin and stop glowing, and this creates a persistence which prevents the patterns changing too fast, and thus they survive long enough to be perceived. (More recent types of screens, such as plasma display, LCD and LED, can also be used)).

The resulting images depend on different camera and monitor settings, such as light amplification, contrast, distance, angle and physical vibrations. Optical feedback can be combined with music, or other sound sources, to influence the image loop.

Read more about Optical FeedbackVideo Feedback, In Entertainment, In Science, In Philosophy

Other articles related to "optical feedback, feedback, optical":

Videofeedback - In Science
... The optical feedback discussed so far—video feedback, created by a camera pointing at its own monitor—is actually just one particular example of optical feedback ... Perhaps the most obvious example of optical feedback in science is the optical cavity found in almost every laser, which typically consists of two mirrors ... Optical feedback in science is often closely related to video feedback, so an understanding of video feedback can be useful for other applications of optical feedback ...
Video Feedback - In Science
... The optical feedback discussed so far—video feedback, created by a camera pointing at its own monitor—is actually just one particular example of optical feedback ... Perhaps the most obvious example of optical feedback in science is the optical cavity found in almost every laser, which typically consists of two mirrors between which ... Optical feedback in science is often closely related to video feedback, so an understanding of video feedback can be useful for other applications of optical feedback ...
Optical Feedback - In Philosophy
... Douglas Hofstadter uses a direct analogy to Optical feedback (video feedback) in his book I Am a Strange Loop about the human mind and consciousness ...
Videofeedback
... Optical feedback is the optical equivalent of acoustic feedback ... A simple example is the feedback that occurs when a loop exists between an optical input, e.g ... a video camera, and an optical output, e.g ...

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