After posting this thread:
http://www.gimpchat.com/viewtopic.php?f ... 5b966818e7

I've noticed that colors and brightness we see depend on the configuration that each of us have on our monitors or LCD panels. So the idea would be to find a site that allow for some online test to obtain a common configuration to all users. In this way we ensure that everyone is seeing something similar.

Do you know a website that allows you do that?

I remember once having made a test where depending on brightness/contrast settings, I could read the text or the text disappeared. Also similar with colors, where an image is viewed or disappear depending on the configuration.

You could try having a look at the Cambridge in Colour web-site, especially at the monitor calibration page: http://www.cambridgeincolour.com/tutori ... ration.htm

Kevin

Thank you, paynekj. It is possible learn a lot from this web site.
I remembered that KDE has excellent Gamma calibration module (Kgamma). I think in Windows video drivers also have those tools. But it would be nice to find something online that is easy and common for all.
I've found this:
http://www.photofriday.com/calibrate.php

Basically, changing the gamma/brightness/contratse on your system and/or monitor you should be able to see all the gradient in rectangles and circles. For example, with the circles test you should find a average configuration where you can differentiate all concentric circles. Those on the left not too dark and on the right not very bright.
I configured correctly the gamma and now I can see the horrific imperfections in my edited photographs

Thanks for the links, but one quick question, I can adjust the monitor settings or I can adjust the graphic card settings. Is there a preference as to which is best to adjust.

I'm not sure. But I think it's better to try to get the best settings from the monitor controls. And then fine tune from the driver settings.

If you use Linux and your distro carries it I would suggest to use monica. (monitorcalibration)
Once installed you can read the readme in /usr/share/doc/monica.
It is a simple and good calibration program.
Gerard.

Edit:Here's a link to a picture to judge your monitor.
http://imgur.com/zt9i5

@gerard82, I can not find the sources to compile. Apparently the official site no longer exists.
I found a rpm package and the binary inside asks for "libfltk.so.0" (fltk), and I have installed "libfltk.so.1.1" version.

You're right YAFU,can't find the site either.

Untar the file and you'll see that it needs fltk >= 1.1.x.
The "install" file contains info on how to proceed.
Hope this is of help to you.

In case you wonder where I got the source so quickly:
Gentoo downloads all software as source and then compiles it on your computer.
The source is kept in a special file called "distfile".
I could also upload fltk-1.3.0-r1 source if this site allows 4+ MB files.

Good luck,
Gerard.

I have not been able to compile. But I found the application written in Python by the same author of monica:
http://wtanaka.com/node/7968
Here I upload the file so that it is not lost:
http://www.fileswap.com/dl/t10NYg9L/GAM ... n.zip.html
Extract the file, make sure it is executable and run it.

The test is really simple and useful. Thanks Gerard!

You're welcome of course.

I d/led the python program and will compare it with monica.
Gerard.

I tried GAMMApage.py.
It's identical to monica except you can't run it full screen.
Gerard.