Monitor Calibration question

[aron]

I am calibrating a CRT and have some questions. When using the photo

cal software, you come to an option that asks you to adjust

brightness to where you can just see the four grey squares. I want

to make sure I understand this correctly becuase when I look at an

image on both my CRT and then my calibrated laptops LCD, the image

(after adjusted) is well over exposed on the laptop, but just about

right on the newly calibrated CRT. My question is do you just barely

want to be able to see distinctly the 4 grey squares, or should you

adjust up to see them a little better when adjusting brightness? I

would hate to adjust a bunch of images only to have them all come

back over exposed.

[jeff medkeff anchorage, a]

My short answer is that trying to calibrate a laptop is a little like herding chickens. Some people can do it to some chickens with some (usually modest) degree of success, but it never really works very well, it tends to be messy and chaotic, and there is generally a lot of cussing.

 

Anyway, you want to just barely be able to see the four gray squares (or, in some software, the interface). That said, turning down brightness on an LCD is not the same as turning it down on a CRT. In the former case, the dynamic range of the display's output is constant regardless of brightness setting (except on some displays where a certain number of light sources turn off). This complicates things. To get a better LCD profile, I recommend three things that I think I'm smart enough to know about:

 

- take an ambient light reading with your device if this is available with your hardware/software. If it is optional, do it anyway.

 

- wait two minutes after turning the brightness down before you take a measurement, and wait another two minutes after turning the brightness back up. It can take some time for such adjustments to stabilize.

 

- if there is some way to know if there was clipping on the max contrast measurement (the one you turn the brightness down for), use it. If you are clipping, you can keep trying that step with different brightness settings until it isn't clipping anymore; alternately, some software provides its own recovery step. (Some systems will ignore clipping and let you think things are just fine, in which case you are out of luck.)

 

Even paying close attention to these things is no guarantee. It is entirely possible that your LCD cannot be calibrated at all, no matter what hardware/software you throw at it. Good luck.

[aron]

Well, I will now primarily be using the CRT and only the LCD when I have to go portable. It sounds safer to do it this way. Keep in mind, my LCD is not exactly pro quality, only a laptop which is why I am going 'old school' and re-introducing the good old CRT. Thanks for the suggestions though

[ethan hansen]

The only hardware adjustment your laptop offers is how bright the backlight is. Adjst that to where you want - full bore for maximum color and contrast range, dimmer if it makes your eyes hurt - and let the shadows fall where they may. Do *not* make adjustments based on black levels or you'll throw everything off. The profile will act as a linearization tool to some extent. This helps preserve shadow contrast. The black level of your laptop screen will never match that of the CRT, unless that is you dial the backlight down to nothing.