24-bit LCD Notebooks

[Steffan]

I'm looking to purchase a Notebook to use as a Portable image store and desktop replacement.

Although it is fairly easy to find out the Processor, Memory, Harddrive, Graphics chipset, Screen size and whether it has a X-Bright (or similar) style display (even the contrast range) - finding out whether a given machine has an 18-bit or 24-bit LCD is proving somewhat harder.

The Quosmio range for example does not have a 24-bit display (according to the Toshiba site), but when trying to compare the Vaio ranges it proved impossible to get an answer from either the Vaio-Link site, Sony sales, or Sony's tech support team.

I'm not looking for a debate on the suitability of a Notebook for accurate photo editing (I may attach an external monitor most of the time anyway) - what I AM looking for is information on which notebooks come with 18-bit displays and which with 24-bit.

TIA

[Robert Spoecker]

I pulled this info off of my Macintosh PowerBook G4 laptop.

ATI Mobility Radeon 9700:

  Chipset Model:   ATY,RV360M11
  Type:   Display
  Bus:   AGP
  VRAM (Total):   64 MB
  Vendor:   ATI (0x1002)
  Device ID:   0x4e50
  Revision ID:   0x0000
  ROM Revision:   113-xxxxx-145
  Displays:
Display:
  Type:   Display
  Display Type:   LCD
  Resolution:   1280 x 854
  Depth:   32-bit Color
  Core Image:   Supported
  Main Display:   Yes
  Mirror:   Off
  Online:   Yes
  Quartz Extreme:   Supported

It seems to say 32, not 18 or 24 bits debth.

Is this what you were loking for?

Robert

[Steffan]

Thanks, that's sort of the information I was looking for although the colour depth of the signal does not always coincide with the colour depth of the display device.

As I understand it 32-bit includes alpha data but only 24-bits of colour. Add to that the fact that a number of displays use a dithered 18-bit display (alternating the individual sub-pixels during the refresh rather than the consecutive pixels as used for gifs or printed output), and you can see how difficult it can be to get to the truth.

Unfortunately for various reasons I also need a Windows based system.

[Jonathan Wienke]

The other issue to keep in mind is that "32-bit" probably refers to the video card, not the display itself. If you have an 18-bit display, it would simply downsample the video signal internally. The good news is that means that you can get full use out of an external display even if the internal one is crappy.