How do colour profiles work?

If I create a colour profile for a monitor does that override the monitors colour adjustments or does it side alongside? If it's the latter am I better to put the monitor to a factory default then calibrate to do as much adjustment as possible in the profile or do I do the heavy lifting with the monitor and fine tune with the profile?

you have few situations:
1) 8bit GPU (Nvidia and Intel and very old ATI cards) without dithering and monitor with 8-bit internal precision
In this case you are screwed up. You either set monitor to one setting in which it does not have banding which usually be RGB channels all on 100% (might need to use service menu for that) and find gamma setting which produce no banding. Then you do calibration on PC. Or... you set monitor to match whitepoint and then do calibration on PC which will result in more banding but games will have proper whitepoint. You get banding either way.

2) AMD Radeon and monitor with 8-bit internal precission
You find setting in monitor that do not have banding and do calibration o PC. You then have no banding. If you set whitepoint in monitor you will have banding but proper whitepoint in games. Choice is yours.

3) 8-bit GPU and monitor with high internal precision
You absolutely need to set monitor to match desired whitepoint and gamma as closely as possible and then do calibration on PC. That way you minimize banding though you will still have some. You set it by maximizing contrast ratio and do so by keeping at least one RGB channel at 100%

4) AMD Radeon and monitor with high internal precission
You do it like at point 3 but do not have any banding after calibration.

To check if monitor produce banding when you tinker with it settings you use something like this http://www.lagom.nl/lcd-test/gradient.php. Use it also to check if your GPU produce banding when changing gamma/calibrating. Radeons (not sure from which family but HD5xxx should be safe) use dithering and do not produce any banding. NV will have banding on most monitors except when using VGA connection and some rare 10/12bit monitors. You need to check what you have, if you have option to use 10 or 12-bit, if you have banding on GPU, monitor, etc.

Then there is whole issue with "GAMUT" which is resolved in two ways:
a) use CMS aware applications
b) use EDID gamut remapping available on Radeons

option b) work in all applications and games (fire and forget option) but only on newer AMD cards and use informations from EDID which should be accurate but are not guaranteed to be. If you have Radeon then check this option and do measurement. It should be more accurate than without it. It doesn't produce any banding. Especially useful on monitor which have gamut that differs a lot from sRGB gamut. If that is not available you use CMS aware applications. They will either use loaded profile automatically or sometimes need enabling color correction and even loading profile. Firefox and MPC-HC are two application I know can use ICC/ICM files to correct gamut, not sure about other applications.

Either way, it is not that easy as "do this and only this" because it depend on your hardware. There are lots of quirks in monitors and sometimes some serious tinkering is needed. Best to use those lagom lcd images to check for banding, clipping in both white and black. BTW. beware of color corrected browsers when loading those lagom lcd images because color correction might change results. Load those images in non-CMS aware application and check them from there. Then after all is calibrated check how they look in CMS aware application like Firefox to see if all is good.

Good luck, you will need it

Jeezy Creazy.......

OK, first off, thanks very much for all the info, much appreciated. Could you clarify a couple of points for me?

I've got a Radeon HD 5850 card on a Benq BL3200PT and an HP ZR2440W, would I be right in thinking that's scenario 2 for me then?

Are you basically saying that I set the gamma and whitepoint on the monitor but the colour balance in the colour profile? I always assumed once the whitepoint was set the coloour balance would be correct?

Imho you fall of 4th point but you need to actually check (eg. using lagom lcd image I posted link to in my previous post) if changing settings on each monitor and GPU side cause banding or not to be sure and judge your situation on that.

Proper whitepoint != proper gamma response. What do you mean by "color balance"?

In Windows, it is sort of a mess.

It all depends on the application on weather or not to provide gamut mapping. The only thing that does seem to apply more widely is the neutral axis (grey scale, gamma curve) since that can by uploaded to basically all GPUs basic LUT capabilities.

Then your monitor does what it does with what you did to it's menus.

XoR said:

Imho you fall of 4th point but you need to actually check (eg. using lagom lcd image I posted link to in my previous post) if changing settings on each monitor and GPU side cause banding or not to be sure and judge your situation on that.

Proper whitepoint != proper gamma response. What do you mean by "color balance"?

Click to expand...

Christ, I'd forgotten all about GPU colour changes. I'm getting so confused

I've never worried about calibrating monitors before now, (I'm a freelance 3d visualiser) but I've decided to upgrade to a decent display and get my shit together and do this properly. Problem is, the more I read the more confusing it gets. I thought all I would have to do is borrow a calorimeter and bang in a new colour profile but the more I think about it the less likely it seems it's going to be that easy.

As far as colour balance goes, I thought you set your RGB balance separately to your white balance, is that not the case?

umeng2002 said:

In Windows, it is sort of a mess.

It all depends on the application on weather or not to provide gamut mapping. The only thing that does seem to apply more widely is the neutral axis (grey scale, gamma curve) since that can by uploaded to basically all GPUs basic LUT capabilities.

Then your monitor does what it does with what you did to it's menus.

Click to expand...

OK so maybe avoid windows and try to do it all with the monitor itself then?

Monitors with full hardware calibration (gamma and gamut) are 'fire and forget'.

But you need not worry that much about details. Just be sure to buy good probe like eg. i1 Display Pro and do what software tells you to do. Most people do it like that without going into details what happens and how things are done. In the end even if result are not perfect they will be better than uncalibrated display.

XoR said:

Monitors with full hardware calibration (gamma and gamut) are 'fire and forget'.

But you need not worry that much about details. Just be sure to buy good probe like eg. i1 Display Pro and do what software tells you to do. Most people do it like that without going into details what happens and how things are done. In the end even if result are not perfect they will be better than uncalibrated display.

Click to expand...

I loathe the POS software that comes with the Display Pro. TThat other software you cna buy for like 200 bucks is actually decent. Starts with a G IIRC. I really can't comprehend the utter trash of software that comes with the Display Pro.

OK, I'll go on the scrounge and see if I can do it that way, thanks for the feedback.

you don't need to spend money to do a good software calibration.