uriaha wrote:
I'm having the same issue. I just updated to Snow Leopard yesterday and now my 13" MBP seems way too bright.
The first "notch" of brightness (adjusted using the function keys) seems roughly equivalent to the halfway point pre-Snow Leopard. Turning the brightness all the way up is almost blinding.
It may be that your previous calibration was not the Leo default, and SL reset your display settings to default levels, which seems considerably brighter to what you were use to. This would include the calibration for 100% White and 100% Black
Adjusting the gamma doesn't have any effect.
You are correct. The brightest white will NOT be affected by gamma. The reason is, is that gamma refers to the gray mid-point (50% white).
Gamma is the point where gray should be half way between 0-black and 255-white so that the gray levels of a monitor are smooth throughout the brightness range. However, the problem is that gamma only adjusts the 50% white, where actually proper calibration requires setting at least 10 gray levels (i.e. 10% white, 20% white... 90% white, 100% white). In your case, the problem is probably that the upper gray points (over 50% white) are skewed too close to the mid-point, and further away from 100% white (or 100% white is skewed left so the 100% white is remapped to what should be 90% white) causing an inappropriate larger range of the screen being drawn as white, or whiter. So, adjusting the 50% point does very little to the 60%... 90% white points, and you see no change to the brightness of the monitor.
And to complicate matters even more, all monitors have different brightness/color response curves; even the same model may change curves between production batches.
In addition, each OS has its own interpretation of what the proper gamma setting is, based on how the OS displays a screen. i.e. Mac OS 10.6 has a setting of 2.2, where Windows is 1.6 (I think) because Windows draws the screen just slightly darker than Mac OS, and has to compensate with a lower gamma to brighten the display. Previous version of Max OS had gamma at 1.8 (according to tech notes).
re A A P L previous post:
http://support.apple.com/kb/HT3712
Linux has yet another gamma because it
draws the screen differently than either Windows or Mac OS.
It is also possible that the screen drawing algorithm has changed with SL, but for me, gamma seems about the same as before, just the overall brightness changed a bit, which was corrected by recalibration with the hueyPRO.
The easiest way to illustrate what gamma is, is to see the results when you use the
Levels layer effect in Photoshop. The middle adjuster is analogous to the gamma. Move it closer to the black and the overall picture gets brighter (which decreases contrast and lightens dark areas, but brings out detail in the shadows); move it closer to 255 white and the overall picture gets darker (which brings out detail in the lighter areas, but shadows get darker or black). You will also notice if you bring the 100% white point to the left, you will blow out the image without affecting 50% white and 0% white (black). And conversely, moving the black point right, the image gets darker without changing whites.
Regardless of whether you move the mid-point left or right, the blackest possible and the whitest possible parts of the image do not change. This is the same for the gamma monitor setting.
Proper calibration, using a Colorimeter or manually, is supposed to set the proper 0% white (black), 100% white, 50% white (gamma), multiple gray points and color response curves for the monitor.
Nicolas mentions that he uses a Spider 2 colorimeter, which should be able to properly calibrate the monitor, but seems to be falling short. It may take a couple runs for the Spider 2 to get it right. I use the hueyPRO on my MBP 17", but I made sure the brightness level was up full during calibration, otherwise, the colorimeter will try to set the pure white level to the wrong value.
After I calibrated my MBP at full brightness, I find that I will typically have my screen brightness set at 50%. I find it easier on the eyes. If I am actually doing color correction, I will bring the brightness back up to 100%.
A free tool I used before I got the hueyPRO is
SuperCal. Through a series of guided visual tests, it allows you to "Visually" set the brightness, gamma, multiple gray points and colors levels. Not 100%, but it is easier to work with than Apple's Calibration tool IMO.
Color calibration is very complicated (yes, even
more than my ramblings, and too much so for this discussion). If you download
SuperCal and go through the calibration process, it will give you a better idea of how color and curves are set, and just how non-linear they are. Hopefully, you will also be able to get the monitor displaying to your liking as well.
OK, enough geek speak. To Much Information!! 😉
Hope this helps and Good Luck.
Gary
