CHROMiX

Confusing PM 5 Calibration & Bad Profiles

I’m attempting to profile the LCD of my PowerBook (auto brighntness adjustment is off) with ProfileMaker 5.0.4 and an EyeOne, and I’m running into several difficulties with the application and the profiles it’s generating.

APPLICATION ISSUES
When I start the process, PM asks if I want to do a calibration first, and I select yes. In the screen that appears, I can select several settings: white point, gama, brightness, and monitor type. I have no idea what this brightness setting is (a list from 25% too 100% in 5% increments), and there’s no description of it in the documentation. I assume I should use 100% and continue along my way. What is this and what does it control? Should I use 100%? When would one not want to use 100%?

In the next step, PM tells me to set the contrast to it’s highest setting and then lower it until the arrows line up. My PBook has only a brightness setting. Should I skip this contrast step completely (without hitting the start button)? Or should I hit the start button and change the brightness settings being well aware that I’m just going to change the brightness level in the next step? I just want to be assured that PM isn’t going to generate a bad profile because it was expecting to get a value from the contrast step that I skipped. I gather that in skipping that step the application is having to use an assumed value, and I want to know the implications of this assumed value when PM goes through its mathematical manipulations to generate the profile.

When I do get to the step in which I need to select a brightness level, PM prompts me to select an unexpectedly low brightness–7 out of 16 bars on my display, which PM reports as 44-53 Cd/m2. (PM doesn’t give the luminance directly, but when I create the next profile a luminance value is listed in the system status box, and I assume that to be the value from the previous profile made. As a sidenote, I’d like to know how to measure the luminance of my screen; I don’t see any spot measurement function for luminance in PM). If I recreate a profile with the same settings in PM, sometimes the brightness PM tells me to choose jumps to 10 of the 16 bars on my display. This jump is intermittant, and I’m always finding myself selecting a brightness of 7 or 10 bars, nothing in between. Even at 10 bars, I’m only up to 67 Cd/m2. Why is PM having me choose such low brightness levels?

PROFILE ISSUES
In an attempt to be thorough, after generating a profile, I’ve reprofiled immediately without changing any settings in PM (the same brightness level is chosen as well). What I’ve found, unfortnately, is that color casts (usually red) appear intermittently. The results are random… and very frustrating. The color cast is most noticeable in the black background after the first 15 patches of the calibration swatches are measured and PM makes an adjustment before going on to the optimization and chart patches. Has anyone else seen such variability in profiles? Could it be related to PM having me choose such a low brightness?

Any comments and advice would be greatly appreciated. I had hoped to spend the holiday weekend doing something a bit more entertaining than wrestling with unpredictable profiles.

I can’t answer all your questions, but from my experience in attempting to calibrate/characterize a Powerbook LCD, my advice is to find something better to do and enjoy the weekend. :wink: I haven’t tried PM5, but I have tried several other profiling packages (Optix XR Pro, i1Match) in a vain attempt to get a stable response from a Powerbook monitor, but I just couldn’t get it. The reults I’ve seen are similar to what you describe… about 73 cd/m^2 and an apparenently casted profile. I don’t blame the software, I blame the screen.

Skipping the contrast step is correct, and as far as setting the brightness, at least with the Optix package, I could set brightness to ANY level, and after a few measurements, the software would indicate it was too bright. I’ve never had any of these problems on any other quality monitor. So I really don’t think the issues are related to the profile software or your settings, but are the fault of the Powerbook screen. If anyone is getting good results with their Powerbook screen, I hope they’ll chime in.

Mike,

I’m glad to hear others have observed what I’m seeing. I recall, however, reading posts (on the Colorsync list, I belive) in which people noted they had profiled their PowerBooks without issue, which is why I endeavored to profile mine this weekend.

I’m going to repeat the process today with my Spyder and OptiCAL 3.7.7 to see what kind of results I’ll get. I only started with the EyeOne and PM 5 because I thought it’d give superior results…