I recently got a chance to test drive two "identical" Macbooks. (C2D 2ghz, 80GB HD, 1GB RAM). I've noticed significant differences in the LCD panels, and decided to write up this post.
I know that no 2 LCD panels are ever the same. Apple is stuck using 6 bit LCD panels that can only show 2^6 x 2^6 x 2^6 = 262,144 colors. Yet the video card outputs 2^8 x 2^8 x 2^8 = 16,777,216 colors. As such, the color rendition is only as good as the panel being used due to color conversion done by the panel.
Test setup:
- All pictures were taken using a Canon Digital Rebel with a 24-105 f4L pro lens
- Pictures were cropped/resized only
- Machines were put side by size in a dark room when images taken
- All defaults being used in Display settings (for font smoothing) and Apple ICC for Color LCD used.
It is important to note that you might be looking at this page on an LCD screen that may not be calibrated. As such, I will try to describe what the image looks like in true life, and hopefully the on screen image in this post will match.
LCD Comparison:
System 1:
- Made mid February, 2007
- LCD Model 9C5B / 42716C0
- This panel looks great from any angle you look at it
System 2:
- Made last week of March, 2007
- LCD Model 9C5F / 42717C0
- This panel looks great from any angle you look at. But you do seem to notice the coating used on the panel when you look at it at an angle. It seems like an inch wide bands across the screen.
result: It's not really apparent from the images above, but 42717C0 is much brighter! using the same camera settings (f4 and ISO 400) the shutter speed for 42717C0 was almost twice as slow! Visually, the horizontal lines in dialog boxes and menus are washed out for 42717C0 while visible for the 42716C0.
Gray Scale Test:
- You can find the test pattern on www.dpreview.com. Every single one of their camera tests has this on the bottom of the first page.
42716C0:
42717C0:
result: You should clearly notice that 42716C0 has a uniform gray scale pattern (no 2 letters are the same). While for 42717C0, A & B seem the same.
Winner: 42716C0 - perfect uniform gray scale pattern.
Font clarity/smoothing:
Text is the the visual entity most often seen by computer user. You're reading it now, you interact with it through dialog boxes and menus, you use it in e-mails and general web browsing.
This test compares fonts between the 2 LCD panels.
42716C0:
42717C0:
result: This is by far the biggest noticeable difference, and the thing that prompted me to run these tests and post this. Because 42717C0 is much brighter, it seems that it has an ill effect on font smoothing. Text seems to be "thinner" and more aliased. 42716C0 seems to have bolder, smoother looking text.
Winner: 42716C0 by a long shot. Even windows (running in Parallels) looks as good as on my old IBM Thinkpad! It just looks wrong on 42717C0.
Color Banding / Gradience:
Due to the 6 bit color rendition of most LCD panels, color banding is a very common problem. The idea is to feed 16 million colors into the panel, and see how it behaves.
The way I tested this is to run the LCDTest program found here:
http://www.bjorgs.com/wiki/index.php?title=LCDTest
42716C0:
42717C0:
result: 42717C0 seems very uniform and clean of any problems. 42716C0 on the other hand shows many issues. There's a clear green line in the green spectrum. In the red spectrum, the image pixelates in small squares!
In fact, the pixelization in visible in other colors as well. The following image should show the problem more clearly:
These strange color artifacts (square blocks of color, rather than uniform dispertion) show up in some photos I've taken with my camera while on vacation on the 42716C0 panel. On the 42717C0, the color is uniform.
Winner: 42717C0 by a long shot. There are many forums that discuss the 42716C0 LCD panel and its green band issues (see here: http://www.macuser.de/forum/showthread.php?t=187331)
Overall conclusion:
42716C0:
Pro:
- Excellent gray scale (probably due to the fact that the panel is not as bright)
Con:
- Not as bright (which might be a good thing, if you use your machine for a long time)
- Color banding (not good if you do any photo editing)
42717C0:
Pro:
- Very bright display
- No visible color banding (excellent for photo editing)
Con:
- Too bright - causes fonts to wash out and images to look over exposed. But this might be the "fix" for color banding -> really bright image
Any comments??
What LCD panel would you rather have in your system?
I know that no 2 LCD panels are ever the same. Apple is stuck using 6 bit LCD panels that can only show 2^6 x 2^6 x 2^6 = 262,144 colors. Yet the video card outputs 2^8 x 2^8 x 2^8 = 16,777,216 colors. As such, the color rendition is only as good as the panel being used due to color conversion done by the panel.
Test setup:
- All pictures were taken using a Canon Digital Rebel with a 24-105 f4L pro lens
- Pictures were cropped/resized only
- Machines were put side by size in a dark room when images taken
- All defaults being used in Display settings (for font smoothing) and Apple ICC for Color LCD used.
It is important to note that you might be looking at this page on an LCD screen that may not be calibrated. As such, I will try to describe what the image looks like in true life, and hopefully the on screen image in this post will match.
LCD Comparison:
System 1:
- Made mid February, 2007
- LCD Model 9C5B / 42716C0
- This panel looks great from any angle you look at it
System 2:
- Made last week of March, 2007
- LCD Model 9C5F / 42717C0
- This panel looks great from any angle you look at. But you do seem to notice the coating used on the panel when you look at it at an angle. It seems like an inch wide bands across the screen.
result: It's not really apparent from the images above, but 42717C0 is much brighter! using the same camera settings (f4 and ISO 400) the shutter speed for 42717C0 was almost twice as slow! Visually, the horizontal lines in dialog boxes and menus are washed out for 42717C0 while visible for the 42716C0.
Gray Scale Test:
- You can find the test pattern on www.dpreview.com. Every single one of their camera tests has this on the bottom of the first page.
42716C0:
42717C0:
result: You should clearly notice that 42716C0 has a uniform gray scale pattern (no 2 letters are the same). While for 42717C0, A & B seem the same.
Winner: 42716C0 - perfect uniform gray scale pattern.
Font clarity/smoothing:
Text is the the visual entity most often seen by computer user. You're reading it now, you interact with it through dialog boxes and menus, you use it in e-mails and general web browsing.
This test compares fonts between the 2 LCD panels.
42716C0:
42717C0:
result: This is by far the biggest noticeable difference, and the thing that prompted me to run these tests and post this. Because 42717C0 is much brighter, it seems that it has an ill effect on font smoothing. Text seems to be "thinner" and more aliased. 42716C0 seems to have bolder, smoother looking text.
Winner: 42716C0 by a long shot. Even windows (running in Parallels) looks as good as on my old IBM Thinkpad! It just looks wrong on 42717C0.
Color Banding / Gradience:
Due to the 6 bit color rendition of most LCD panels, color banding is a very common problem. The idea is to feed 16 million colors into the panel, and see how it behaves.
The way I tested this is to run the LCDTest program found here:
http://www.bjorgs.com/wiki/index.php?title=LCDTest
42716C0:
42717C0:
result: 42717C0 seems very uniform and clean of any problems. 42716C0 on the other hand shows many issues. There's a clear green line in the green spectrum. In the red spectrum, the image pixelates in small squares!
In fact, the pixelization in visible in other colors as well. The following image should show the problem more clearly:
These strange color artifacts (square blocks of color, rather than uniform dispertion) show up in some photos I've taken with my camera while on vacation on the 42716C0 panel. On the 42717C0, the color is uniform.
Winner: 42717C0 by a long shot. There are many forums that discuss the 42716C0 LCD panel and its green band issues (see here: http://www.macuser.de/forum/showthread.php?t=187331)
Overall conclusion:
42716C0:
Pro:
- Excellent gray scale (probably due to the fact that the panel is not as bright)
Con:
- Not as bright (which might be a good thing, if you use your machine for a long time)
- Color banding (not good if you do any photo editing)
42717C0:
Pro:
- Very bright display
- No visible color banding (excellent for photo editing)
Con:
- Too bright - causes fonts to wash out and images to look over exposed. But this might be the "fix" for color banding -> really bright image
Any comments??
What LCD panel would you rather have in your system?
