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Author Topic: Why is Convergence Important on CRT projection TV's Lyle Romer Phenomenal Film Handler Posts: 1400 From: Davie, FL, USA Registered: May 2002 posted 12-30-2008 12:23 PM                     OK, here is something I've been thinking about. Why is it that on a CRT (and I'm assuming 3-chip DLP) projector, convergence of the three colors is very important but........ In an LCD or Plasma display (or even large LED display), each "pixel" is really a red, green and blue pixel next to each other. I guess in this case, our eyes are really seeing 3 completely separate images and integrating them into one full color image. So that brings me back to my CRT/DLP question. How come if the convergence is off, we can see it when we can't on other types of displays.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 12-30-2008 01:24 PM                     Ignorant hypothesis: what we perceive as "bad convergence" on a CRT is substantially larger linear distance than the inter-subpixel distance on an LCD? --jhawk  |  IP: Logged Mark Ogden Jedi Master Film Handler Posts: 943 From: Little Falls, N.J. Registered: Jun 99 posted 12-30-2008 02:10 PM                     John is right, because in solid-state display devices, the convergence is never really "off", as after the manufacturing step nothing is ever converged. That is to say, the red, green and blue pixels, be they lcds, plasma capsules or micro-mirrors, are permanently fixed in position in a very small area relative to each other, nothing is variable in the way they illuminate save for the actual input signal, and the apparent "convergence" never changes. In DLP devices that operate with separate R G and B micro-mirror arrays, they are precisely aligned at the factory and then permanently fixed in position.  |  IP: Logged Mark Ogden Jedi Master Film Handler Posts: 943 From: Little Falls, N.J. Registered: Jun 99 posted 12-30-2008 02:17 PM                     Whoops, double post . .  |  IP: Logged

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