On Jan 19, 2010, at 9:51 AM, David Reid wrote: > Greetings List, > > Anyone care to comment as to pros/cons of the two backlighting options?: > > > CCFL Backlight (Cold cathode fluorescent lamps) remains a common method for > backlighting an LCD screen. > > LED Backlight is a variant of LCDs which use light-emitting diodes to light > the LCD. LEDs typically use relatively less power, are mercury free, thus > the Greener choice. > >
David, No experience with a T500. Note that there are a variety of LED backlights. The easy one is "white" LEDs with poor color. They basically use a blue (or sometimes UV) LED with phosphor coatings to get white light. Typically they have poor color (peaks in blue and red and relatively less green). There are better white LEDs with a wider color gamut - this allows the screen to display more colors correctly. Most white LED screens cannot represent the full color space. The top end LED backlight displays use discrete red-green-blue LEDs to more carefully represent the color space. I know of only one such notebook panel and Lenovo didn't use to offer it (17" 1920x1200 used in the HP Elitebook with "DreamColor" and some Dell 17" Precision and other notebooks). There may be others. These screens were expensive and required a high-end graphics card (Nvidia Quadro mobile). There are similar high-end good color LCD panels for desktops - again they are expensive (see HP 24" DreamColor monitor - about $2K vs about $550 for their next best 24" monitor). I note that there is a 95% gamut T500 screen available. I don't know if this is a white LED or RGB LED unit. If real RGB, it would probably be worth it if you desire good color rendition on the screen. Sometimes there is a tradeoff between brightness and color. The HP 24" DreamColor is dimmer than the 24" HP with CCFL but the color rendition is WAY better and the panel supports 10-bit per color with the correct video card. You choose what you want and then pay the freight ... Stuart PS - I'm now using an Apple MacBook Pro 17" with a white LED panel. Bright and efficient but color isn't great and off-angle color shift is worse than the old IPS CCFL panel in my now ancient T43p. I wish someone made a discreet RGB LED backlit IPS panel for notebooks but the cost would be high and the manufacturers have decided there isn't sufficient high end market to justify it. The notebook DreamColor from HP is not IPS but the 24" DreamColor is and the 24" has better color and wider view angles. _______________________________________________ Thinkpad mailing list [email protected] http://stderr.org/cgi-bin/mailman/listinfo/thinkpad
