I've made a test pattern to see this issue without glasses :
![Image](http://www.mtbs3d.com/gallery/albums/userpics/24608/thumb_RGB_50_test_pattern.jpg)
Once projected with my Optoma EP739H I get this:
![Image](http://www.mtbs3d.com/gallery/albums/userpics/24608/thumb_Uncorrected.jpg)
Looks pretty bad.
So, to correct this issue, i build an electronic circuit :
This circuit dims the video signal according to RV1, RV2 and RV3 potentiometers synchronously with the DDC signal that drives the glasses.
SW1 and SW2 are a single double switch that invert the side (L/R) of the correction.
there is also a switch to invert le DDC signal for the glasses(SW3).
![Image](http://www.mtbs3d.com/gallery/albums/userpics/24608/thumb_Ocilloscope.jpg)
A : DDC signal (pin 12 on VGA)
B : red video signal
with the circuit activated and adjusted :
![Image](http://www.mtbs3d.com/gallery/albums/userpics/24608/thumb_Corrected.jpg)
It works great at the price of brightness loss, we can compensate a part of this loss by pushing the RGB gain at 150% on the projector menu.
I want to buy the Nvidia 3D vision glasses, but is the DDC signal still sent on the VGA port ?
This is a (poor ?) translation of the same topic on the french section :
http://www.mtbs3d.com/phpBB/viewtopic.php?f=41&t=6052" onclick="window.open(this.href);return false;