Profiling vs. Calibration

Can someone clarify the difference (if any) between CALIBRATING a monitor and PROFILING a monitor.

The words seem to be used together (as in "calibrating and profiling your monitor") or interchangeably -- but I think their meanings must be different. Thus, a well calibrated monitor might not be well profiled.

I could give my own opinion on the answer to my question - but I'm interested in what others have to say. Thanks.

When you finish calibrating the end result is a color "profile". It's an "icc" file that you define in display settings and some of the applications. In Windows that file is specified in the "Advanced" settings of your display properties under "Color Management".

Thanks. I just re-read a part of "Real World Color Management" by Fraser et al. - and your explanation is right on target. The book has a sub-chapter on "Calibration and Profiling." It seemed like the authors were using the terms interchangeably. But they were not ... and so, you can calibrate a monitor and not actually complete the profiling because you forgot to save the ICC profile.

If you will allow me to fill that out a little bit...

Calibration for photo work:

Step 1 - with a colorimeter and/or software, setting your monitor to a color temperature of 6500 Kelvin and gamma 2.2, and setting its white and black points by you pushing your monitor's buttons or twiddling its knobs.

Step 2 - calibration software alone or with the assistance of a colorimeter writes the fine corrections to the Look Up Table (LUT) of your graphic card.

Profiling:

Based on the results of calibration and the properties of your monitor, software writes an ICC profile as a reference for your operating system and programs as to how to display graphics on your monitor and sets it as the default profile under display color management. The profile does not interact with the monitor at all.

Since monitor properties change with age and operating conditions, and some software such as games, or you yourself, play with resolutions, color depth and/or refresh rate, you need to periodically repeat the process monthly or less.

John_T,

While we've got your expertise online here, perhaps you can fill out a bit more. . .

Is this how the monitor ICC profile works (simplified): A graphics applicatioin wants to display a specific color. The application looks up the color in the monitor ICC profile and gets the proper instruction to send to the monitor's RGB guns.

But ...

The monitor ICC contains a LUT that maps a device-independent color space (e.g. CIE Lab) to the monitor's RGB color space. If the application has a color management system (e.g. Photoshop), then it is clear how the monitor ICC can be used. But if the application is not color managed, how does it "interact" with the monitor ICC and its look up table?

Someone correct me if I am wrong, but let's say if you display an sRGB image in color managed and non color managed programs they should look more or less the same because the operating system is basically a sRGB color space. If you display an AdobeRGB image in the same programs, the image will only display correctly in color managed programs, provided they implement color management properly and are set up correctly.

To accurately see the differences you will need a high quality graphics card and a colorimeter calibrated good quality monitor, otherwise you are groping in the dark, using your printer as a monitor which is very ass backwards and you will run around in a vicious circle that will usually only get worse. In my experience, the graphic card is more important than the monitor. The only gunslinger in the chain is the graphics card. The monitor is a dummy that does what the card says. The profiles are rules and instructions on how towns people should to talk to the gunslinger if they expect him to shoot the baddies and not them(you).

Most cameras work in sRGB and some allow you to select Adobe RGB, so these will be the color spaces you will almost always be working in and there is little or no advantage in converting them to anything else on your computer.

Output to your printer will normally be managed by the printer driver for a certain range of papers so there is usually no need to assign a profile as the printer is taking care of that. If you are using papers that are not listed in the printer driver, then it is helpful to have a custom profile for your printer using that paper. Some paper manufacturers provide profiles for different printers and their papers, or recommended setttings in your printer driver for those papers, for example Photo Glossy, Fine, yellow +15. Of course the quality of your printer and even the local weather will determine how your prints come out.

If you are outputting to an outside lab, you can apply their profile to your output, but if they are competent it would be better to send them the image in it's native color space and let them do it. Same would apply if you are sending an image to press. Unless you are providing the whole document, let them do it.

If you are outputing to the web, the universal color space is sRGB.

There are a variety of color spaces and you can profile almost anything, however most people's needs are confined to very few. Most people will shoot their pic, do their PS thing and print with no hoohaa. However, you can only do your PS thing with any hope of success if your monitor is at least colorimeter calibrated and profiled.

...and of course, you have much more control if you are shooting RAW than JPEG. Color space is the same in both, though the implementation through RAW>TIF,PSD whathaveyou will be better than JPEG.

Hope this is sufficiently confusing...

I'm not to sure I'll sleep any better tonight knowing there are desperados out there in my world of color -- but I do appreciate your very thorough response. Perhaps we can get you into an expansive mood again on a tamer topic

Cowpoking? Green grow the lilacs all sparklin' with dew, it's been so long dear since partin' with you? That's where Gringo came from...

The computer and digital photography world, however civilized and advanced we like to imagine we are, is still the wild west. Of course it could get very much tamer and simpler if all the bigshots would get together and integrate, refine and simplify, however because of all the vested interests and major egos that's not likely to happen any time soom...

What you describe here is profiling, not calibrating. Calibrating means setting up the controls on the monitor in an optimal way. Profiling means measuring the response of the monitor with a device like the Spyder and building an ICC profile from the measurements.

The ICC profile tells ICC-aware applications exactly how the monitor renders color, so that they can adjust things to display the colors exactly as they should be.