Scorponok
07-07-2003, 10:49 PM
"Recently, posted on a "Pranks" page was some sort of joke messing with your eyes. What it was supposed to look like to the users was a brilliant array of bright colors, which is all the eye can detect. However, computer technicians who tried out this little "prank" began noticing an unusual brightness and slight color distortion on the monitor. The monitor brightness level and color had not been changed though. During the "Fireworks show" a script would go in and change system settings. Undetectable at the time was the increase of gamma output by the monitor. Many computer displays ignore the effect of monitor gamma. The frame buffer values provided by the application software are converted linearly into voltages that drive the CRT in the display. The values in the frame buffer are not proportional to the resulting intensity. A frame buffer value of 1/2 the maximum will produce less than 1/2 the intensity.
At a proper gamma rate, the following image should have 3 sets of squares that have matching brightness levels.
http://www.bberger.net/gamma1.gif
The top row uses gray values; the bottom row simulates the grays by dithering. On a display which corrects for monitor gamma the top squares will have the same apparent brightness as the corresponding bottom squares. On a system which does not correct for monitor gamma the top row of squares will appear darker than the bottom row. Standing about 6 feet from the monitor gives the best results.
Aside from annoyance, the main concern is the human body's reaction to the increase of radiation. While most people may be safe, the many hour computer people may be losing their eyesight, without even knowing it. The increased output burns cells and the retina, permanently shrinking it. Most affected by this are the Cholinergic Amacrine Cells. The Department of Health has issued a warning to the webmaster of such sites, but they fear the script might be present on pages without such jokes. Things like game pages, small image resources, porn sites. Also, a simple test has been posted, which is easily readable by the untampered with monitors, but are extremely distorted by the high gamma output ones. Read it and see if you can see..
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http://www.angelfire.com/mech/cyrotek/death.jpg
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April Fools!
Er... I think I'm a little early..
Or was I a little late?
At a proper gamma rate, the following image should have 3 sets of squares that have matching brightness levels.
http://www.bberger.net/gamma1.gif
The top row uses gray values; the bottom row simulates the grays by dithering. On a display which corrects for monitor gamma the top squares will have the same apparent brightness as the corresponding bottom squares. On a system which does not correct for monitor gamma the top row of squares will appear darker than the bottom row. Standing about 6 feet from the monitor gives the best results.
Aside from annoyance, the main concern is the human body's reaction to the increase of radiation. While most people may be safe, the many hour computer people may be losing their eyesight, without even knowing it. The increased output burns cells and the retina, permanently shrinking it. Most affected by this are the Cholinergic Amacrine Cells. The Department of Health has issued a warning to the webmaster of such sites, but they fear the script might be present on pages without such jokes. Things like game pages, small image resources, porn sites. Also, a simple test has been posted, which is easily readable by the untampered with monitors, but are extremely distorted by the high gamma output ones. Read it and see if you can see..
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http://www.angelfire.com/mech/cyrotek/death.jpg
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April Fools!
Er... I think I'm a little early..
Or was I a little late?