AVS Forum banner
Status
Not open for further replies.
1 - 5 of 5 Posts

·
Registered
Joined
·
4,351 Posts
Discussion Starter · #1 ·
This idea just struck me, I dont know if it has any merit.


The rainbow effect is caused by darting your eyes across the screen thus increasing or decreasing the speed of the wheel relative to your eye.


The rainbows seem to occur when darting your eyes left-to-right. Also, because action occurs more often horizontally, and because the screen is more wide than it is tall, left<->right eye movement is more common. Finally, physiologically it is more comfortable to dart your eyes left<->right than up<->down (try it, you get dizzy going up & down).


This all leads me to believe that the color wheel configuration is probably such that the light is shining through the top or bottom of the wheel to strike the DMD chip. This would be the part of the wheel where the colors are sweeping across horizontally.


Would it not be better to position the light so that it shines through the left or right side of the wheel? At this position, the colors would be sweeping vertically so eye movements in the horizontal direction would not cause the rainbow.


You could test this theory by turning your DLP projector on its side (90-degree rotate) and see if the rainbows are reduced/eliminated.


Andy K.



------------------

"L T One-Fifty

Did your light guide the wisemen,

to baby Jesus?"
 

·
Registered
Joined
·
599 Posts
I don't think it will work. I believe the rainbow has nothing to do with the sweep direction of the wheel, and is purely a function of the time-sliced nature of the image, and your brain combining the red, green and blue images.


Try this. Leave your pj as is, but lay on the couch and watch a 4:3 dvd, preferably black and white. Now dart your eyes back and forth. Your eyes will be moving vertically across the screen. I bet you will see rainbow.
 

·
Registered
Joined
·
9,769 Posts

·
Registered
Joined
·
122 Posts
I do not believe that the color sweeps across the screen with current 1-chip DLP projectors. Micromirrors are all pointing off direction during the entire time that two colors are on the chip. I could be wrong, but I'm pretty sure that's how it works. The archimedes wheel type color-wheel with light recycler that they're working on has flowing colors, but frankly, I am not waiting for it.


I'll take the 3-chip version!
 

·
Registered
Joined
·
6,227 Posts
1 - 5 of 5 Posts
Status
Not open for further replies.
Top