Why does a 1/3 blue, 2/3 black TV screen appear blue from a distance?

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Discussion Overview

The discussion revolves around the perception of color on a TV screen that is 1/3 blue and 2/3 black, specifically why it appears blue from a distance despite the majority being black. The scope includes concepts of light emission, pixel resolution, and human visual perception.

Discussion Character

  • Conceptual clarification, Technical explanation, Debate/contested

Main Points Raised

  • Some participants note that the blue pixels are the only ones emitting light, making them the visible part of the screen.
  • Others argue that black represents the absence of light or color, which contributes to the perception of the blue screen.
  • A participant questions why the screen appears blue when 2/3 is black, suggesting that the perception remains even when the TV is off.
  • Another participant suggests that viewing the screen up close reveals individual blue dots, emphasizing that only the blue pixels are radiating light.
  • It is proposed that resolution plays a role; from a distance, the blue and black pixels merge visually, leading to the perception of blue due to the emitted light from the blue pixels.

Areas of Agreement / Disagreement

Participants express differing views on the influence of black pixels and the role of resolution in color perception. The discussion remains unresolved with multiple competing perspectives on the phenomenon.

Contextual Notes

Limitations include assumptions about visual perception, the influence of distance on pixel visibility, and the conditions under which the screen is observed (on vs. off).

frenzal_dude
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If the blue screen on your TV is only 1/3 blue, 2/3 black, why do we see it as blue?

(Each pixel on a Cathode Ray Tube TV is made up of 3 phosphor dots, red green and blue, so when you have a blue screen, only the blue dot is lit up).
 
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The blue pixels are the only ones that are giving off any light, so they are the only ones you can see. Black is merely the absence of light or color.
 
Drakkith said:
The blue pixels are the only ones that are giving off any light, so they are the only ones you can see. Black is merely the absence of light or color.

True, but when the TV is turned off I can still see the dark screen just as much as I can see the blue screen when it's turned on.
So why if 2/3 of the screen is black, the screen still looks blue?
 
frenzal_dude said:
True, but when the TV is turned off I can still see the dark screen just as much as I can see the blue screen when it's turned on.
So why if 2/3 of the screen is black, the screen still looks blue?

Get real close with a magnifying glass and you should see little blue dots. Since they are the only thing radiating (black is the ABSENCE of radiation) they are the only thing you see.
 
It has to do with resolution, if you get close enough you can see the individual pixels. When you are too far away the blue and black pixels were merge and only the emitted light from the blue pixels will be seen. The black pixels still have an influence, since obviously the intensity of the light will be less than when all the pixels would have been blue.
 

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