Display Calibration - Adobe RGB 1998

I also tried to calibrate the new high-res display. But all the colors are less saturated to. I tried many diffrent things (white temperatures, luminance and so on) but the display is not able to show the sRGB color space and even not the AdobeRGB color space (checking with GretagMacbeth ProfileEditor). This display (including the problem with the horizontal lines) is really ****.
My intent at buying this powerbook was to replace the 17" (1 GHz) model to use Aperture during travelling. But this is not possible with that kind of lousy display.
If I had known that fact before buying the powerbook I never had bought it...
Any other experiences by other users? Any suggestions?

Adam ,

Color management is a complex subject.

It is not possible to calibrate your display to Adobe98.

It is however possible to use a device like the eyeone or optix to measure your display's output, then build a 'profile' which describes the output capabilities of your display.

During this measurement process you will be able to set the hardware 'black point' with the 'brightness' controls on the LCD, you will also be able to set the color of the 'white point' (the color tint of the greys) and the 'gamma' (which is like contrast). The white point and gamma are achieved by the video card and these choices are stored in the VCGT tag inside the profile.

In practice with the PB, you'd attach the sensor to the LCD then start the profiling program.

Adjust the brightness buttons and as prompted for the black point. Note this brightness setting somewhere as the profile is only valid at this setting.

The program will then ask what white point you'd like. 5000k looks too yellow on most monitors, 7200k usually looks too blue, 6500k is often the way to go.
The other option is to use the native white point of the monitor, which I'd guess is way too blue on a PB since it doesn't have hardware white point adjustments to bring it into whack.

It is easy to build a profile for a few different white points and try them out to see which is best. I usually try the native and 6500 options.

Gamma is easy. Use 2.2 gamma for LCD and CRT. Macs used to be 1.8 gamma machines, not anymore.

Hit the save profile button and save it to Library>Colorsync>profiles>display.

Open monitor preferences and hit the color tab. Choose one of the profiles you created, then try another. Observe to changes in color in open programs.

You DO NOT need to mess with the setting in the colorsync preferences, just leave em on the default...in fact , never open that CP.

The reason is, color matching in non Adobe applications is hit or miss. The monitor profile is the most important link and most apps get that one right anyway.

Abobe apps like Photoshop use their own color management and bypass the colorsync CP all together. This is a good thing and the reason why Photoshop is one of the few programs with reliable color matching.

As for Adobe98... Adobe98 is a Photoshop "working space" It is much larger than most monitors..especially a PB LCD.

Adobe98 is a 2.2 gamma profile with very saturated RGB primaries.

Your new monitor profile will be a 2.2 gamma profile with less saturated primaries.

It is the job of color managed apps like photoshop to figure out how to attempt to display the more saturated colors of A98 on the PB... essentially, some colors get clipped on the display.

So forget about the colorsync CP and make sure Photoshop is using the right monitor profile and using the right CM policies. I just set it at 'US Prepress defaults' in the color settings and fiddle with my chosen working space.

Check out Andrew Rodneys , digital dog tutorials of buy real world photoshop from Bruce Frasier for more info.... or step into the dark side at the colorsync users group mailing list here at Apple.

As for the 15' powerbook...my color *****.
I calibrate to 2.2 at 6500k but the greys are still too blue compared to my good CRTs.
My PB also has horrible gradations . The black looks good but the near blacks are way too light.

I calibrated and profiled using Gretag's eyeone monitor package.

Monaco Optix might do a better job.

In the end, the PB displays are just not good enough for color critical work.



2x2 G5 10.3.9 - 2006 15" PB 10.4.3

Adam,

One more thing. You posted you are trying to get your PB to match your 20" CinemaDisplay.

The short answer is...It never will.

Here's how color Mgt works.

Our example will use 2 monitors... your PB and 20" ACD. It works the same way between any other 2 devices.

Your cinema display is like the 64 color box of crayons. It has bright colors and should display a wide range of subtle colors. It does this because it is a High quality device with a large 'gamut' (range).

Your PB screen is like the 16 color box of crayons. It is missing some of the saturated colors and some of thew subtle ones as well. It does this because it has arguably lower standards than the 20" ACD. The constraints of the PB design might now allow for such dynamic color, it has a smaller gamut.

So the 20"ACD and the PB are apples and oranges and would never look the same side by side.

Through the magic of ColorMgt it may be possible to 'dumb' down the color on the ACD to mach the PB in an attempt to match the 2. It is impossible to easily increase the gamut of the PB to match the ACD.

In practice, you would start by building profile of each device to describe the number and intensity of the 'crayons'.

Then suppose you have an image open in a color managed app, like photoshop. Lets suppose this image is in the color space Adobe98 and is a sunset with very saturated reds , say 240R 0G 0B.

The red in A98 image is passed through the 'profile connection space' (PCS) which is usually Lab color space. (in Photoshop the PCS might also be XYZ color space but it's not important)

Photoshop would then find the red in Lab that matches the 240R in A98. Lab is big and holds all the colors of A98. This Lab PCS is the 'reference' color space, the translator if you will.

Then photoshop would render that Lab red to the closest match in each of the monitor profiles you created for the PB and the 20" ACD.

The ACD might actually have that red crayon available but the number is likely different...say 248r 1G 0B...so it could render the red with the new numbers. Same color different numbers.

The PB display probably doesn't have that color of red crayon so it'll look for the closest one. It'll likely peg the red at 255 in an attempt to get close but the reddest crayon is still not red enough.

You could also use the analogy that the image is in Italian but the ACD speaks Chinese and the PB speaks Polish....and The PCS is the dictionary .


In the end, use the Juicy ACD for color corrections and use the PB screen to hold the tool palletes.

2x2 G5 10.3.9 - 2006 15" PB 10.4.3

Excellent color primer, t s4. I learned a lot from it.

I can chime in with reason a PB, or any notebook computer for that matter, cannot achieve the same color gamut, e.g. color saturation levels, as a desktop LCD monitor. You alluded to it. It is a design constraint.

The way to get more saturated color from an LCD is to thicken the R,G,B color filter material applied to the screen during the manufacturing process. However, if you thicken the color filters, even though it has the potential to expand the gamut, at the same time it allows less of the backlight to pass through, hence darkening the display. On a desktop monitor this is overcome by increasing the output from the backlight, either by adding more flourescent bulbs or by increasing the operating current from a lower number of bulbs.

A notebook computer, being required to operate from a battery for an acceptable period of time, does not have the luxury of being able to amp the backlight in this way. So notebook computers have realtively thinner applications of color filter material and hence will never give as good a color gamut as a desktop display.

The whole issue of effective color calibration on LCD monitors will change over the next couple of years with that advent of professional LCD monitors that have independently adjustable R,G,B backlight levels either from LED backlights or from independently colored flourescent lamps as opposed to the white ones used today. When this happens LCD monitors will not only be on par with the best CRT monitors but will exceed them where color gamut and adjustability are concerned.

When you say 'Mac's used to be Gamma 1.8 but not anymore' is that something new? The reason I ask is my PB 1.25Ghz seems to have a Gamma of 1.8 trying to use Gamma 2.2 screws the contrast?
Phil