Screen Tablet malarky => Monitors => Topic started by: Amauril on June 05, 2010, 03:55:43 AM

Title: 6-bit vs 8-bit?
Post by: Amauril on June 05, 2010, 03:55:43 AM
I have noticed that builds are tending toward laptop LCD panels now (in fact, mine will also employ one) - has anyone noticed any appreciable colour differences?  I haven't been able to find a 15 inch panel that is 8-bit (that is, 16.7 million colours); they all seem to be 6-bit (which is 262,144 colours that can simulate 16.2 million colours by dithering.)

I can always go back to my laptop- which has an 8-bit panel (no it doesn't, it's just a really good 6-bit panel apparently)- for colour checking.  I have noticed that some panels are better than others at dithering, just from the several screens other people in the house have.  I'm looking to get an LG-Philips LP150U1-A2, whose datasheet can be downloaded from this page:

Title: Re: 6-bit vs 8-bit?
Post by: bernard on June 05, 2010, 11:50:52 PM
"typical dithering" changes neighbouring pixels and that is quite ugly (reminds of the C64 or EGA-based games).  Nowaday I think none of the LCDs do that.  The more recent ones emulate 8 bit (or near 8 bit) by augmenting the refresh rate (FRC) and doing "a kind of dithering" but on a "temporal" domain (time) -- this proves to make quite good results actually (often unnoticeable).  The reason why 6 bit is popular is price --  TN panels are much cheaper but limited to 6 bit.

A *lot* of 6 bit panels that you find do not do anything to "emulate" 8 bit -- so yes, you can easily see the "steps" in "screen-wide-smooth gradients". Make sure you know what you are comparing against.

Title: Re: 6-bit vs 8-bit?
Post by: Amauril on June 06, 2010, 07:49:13 AM
Your explanation caused me a lot of googling.  I think my headparts might be full now.

I found a more modern panel up for auction, although I probably could have lived with the one I had initially chosen.  Will have to sit on it.  I picked up a 15" SXGA+ IPS panel, an IDTech N150P3-L01, which is generally used in the Thinkpad R50/51 (actually I picked up the complete lid assembly.)  Not that I can find a datasheet for this particular model, although I did find one for the -L04 version (  Seems it will have two circuitboards for me to deal with, but I'm game.  Still 6-bit, but the Thinkpad forumgoers would sell their souls to have the Flexview panels, and the pictures I've seen don't look too bad.

Anyways, it's the best I'm likely to get with a $50 budget. :D

Title: Re: 6-bit vs 8-bit?
Post by: Drewid on June 18, 2010, 07:55:29 AM
You can always clone the display from your main screen so they both show the same thing, so you have another screen to check colour on.