How to Calibrate an Apple Macintosh Monitor
=== by Bob Sutherland ===
This web page describes two methods that you can use to calibrate the display of your Apple Macintosh computer.
Introduction - Why would you want to do this?
Let me begin by saying that anyone who finds their way to this web page probably has been:
- reading too many photography books,
- visiting too many photography web sites,
- participating in too many photography lessons or workshops,
- viewing too many photography related advertisements,
- or attending too many photography club meetings.
Otherwise why would you be interested in trying to calibrate the monitor of your Macintosh computer to fine tune the colours it displays?
Of course there is always the possibility that you are not interested in photography at all. Rather your interest may lie in some other colour intense activity such as interior design or graphic arts work using a computer.
Why is it of utmost importance to you that your computer screen displays the colours you are using with perfect accuracy? The rest of the world is not about to calibrate the colours on their computer screens. Therefore any photographs or artwork that you create are not going to look any better on other people's screens even if you do a better job of fine tuning the colours on your screen.
Have you ever noticed that the colours displayed by a row of computer screens in a big electronics store is not quite right? Maybe from a distance you observed a general blue glow to the light being emitted by the screens. Maybe up close you saw something that should have been pure white on the screen but instead it was tinted blue.
Have you ever scanned a picture into your computer and noticed that the colours of the original image on paper and the copy of the image displayed on your computer screen were not a perfect match? Have you ever experienced problems with the photographs you were printing appearing to shift in colour possibly becoming more red on paper than they were when displayed on your computer screen?
It is quite possible that by now you are thinking a lot of what I have just written does not apply to you. Therefore being an honest webmaster I need to warn you that after attempting to calibrate your Macintosh monitor you may become more aware and sensitive to slight imperfections of colour.
Level One - Find the installed display profiles that have already been calibrated
Your Macintosh computer comes preinstalled with everything you need to calibrate the display of your monitor. The software is part of the operating system of the computer so there is no additional cost. Following these instructions will not harm your computer as everything is completely undoable.
The first step is to open the System Preferences window of your Macintosh operating system. There are a few different ways you can do this so I am providing screen shots and instructions for two methods.

Find the System Preferences icon in the dock along the bottom or side of your Macintosh display. Mouse click on the System Preferences icon to open it.

Find System Preferences listed in the Apple Menu at the top left corner of your Macintosh display. Mouse click on the words System Preferences to open it.

In the System Preferences window find the Display icon. Mouse click on the Display icon to open it.

At the centre top of the Display window you will see two tabs labelled Display and Color. By default the Display tab is selected so you will need to mouse click on the Color tab to open it.

In the window displayed by the Color tab you will see a check mark in the box beside the line "Show profiles for this display only". Mouse click on that check mark to remove it.

In the box labelled "Display profile:" you should now see a few display profiles listed. Your list will probably not be the same as the one displayed in my sample screen shot. It may be shorter or longer.
The list of display profiles changes from one computer to another depending on which model of Macintosh computer it happens to be and which version of the operating system is installed. Attaching a camera, scanner, printer, different monitor or other types of hardware can cause software to be installed on a computer which may include installing one or more additional display profiles.
One of the display profiles is always highlighted. In my sample screen shot the display profile named "iMac" is highlighted and appears with a grey background while all of the other display profiles have a white background. On your computer the highlighted display profile may not be the first one at the top of the list and it may have a coloured background to distinguish it from all of the others. Write down on paper the name of the display profile that is highlighted.
The highlighted display profile is the one your computer is currently using. The other items in the list are alternative display profiles that are currently available on your computer. Go ahead and mouse click on each of the display profiles one at a time. You may notice quite abrupt changes in the colours displayed by your screen for some of the display profiles while others will only cause a very subtle change or no perceptual change at all. Possibly you will find a display profile that you prefer compared to any of the others. At any time you can mouse click on the default display profile that was originally highlighted to reset your computer to the way it was before we started.
Level Two - The free method to calibrate your Macintosh monitor
It is now time for you to calibrate your Macintosh monitor to create your own display profile. When you calibrate the monitor of your Macintosh computer you will be creating a new display profile that will be added to the list you see in front of you. When the time comes be sure to pick a name for your new display profile that is very different from any of the ones that are already on this list. For example, name it after your pet goldfish.
On Windows computers the instructions always say to warm up your computer and screen by using it for at least half an hour before attempting to calibrate the monitor. I do not think I have ever read that advice for a Macintosh computer but it is probably a good idea.
Do not proceed unless you are relaxed, well rested and your eyesight is at peak performance. You are about to do an eye exam that is probably more extensive than anything you have ever done in a doctor or optometrist's office. You do not want to be overtired, stressed out, in a hurry or have blurry vision during this eye exam.

Okay let us begin. Mouse click on the button labelled "Calibrate" in the window that lists the display profiles.

According to my screen shot you are now about to run the Apple Display Calibrator Assistant. I do not know if the program is the same or different for various models of Macintosh computers and different versions of the macOSX operating system. Therefore I am just going to wish you good luck as you go ahead and work your way through the steps of the Apple Display Calibrator Assistant. If you mess up do not worry. I do not think there is any limit as to how many times you can retry this program. Just remember to save your new display profile each time using a different name (e.g. Goldfish1, Goldfish2, Goldfish3 ...).
Level Three - The expensive method to calibrate your Macintosh monitor
When I first used the Apple Display Calibrator Assistant about eight to twelve years ago I was not happy with the results. I therefore did some more research and found articles published by Apple employees on the support pages of Apple.com that recommended photographers should purchase a product called Spyder3 from a company called Datacolor. The company is still in business and has a website https://www.datacolor.com/spyder/ . They have updated the version of their product so that it is now called SpyderX. From what I can tell looking at their website the modern SpyderX looks and works similar to the Spyder3 version that I purchased years ago.
I purchased the Spyder3 hardware online from a computer store in Toronto, Canada. The Spyder3 hardware was a light sensor that looked like a "T" shaped computer mouse with a long USB cable. There was a light sensor lens on the bottom surface of the Spyder3 hardware in exactly the same centred position that the laser light or scrolling ball is located on the bottom of a computer mouse. After registering the product with Datacolor I was able to download the Spyder3 Pro software for free from their website. They also offered Spyder3 Elite software that included everything the Spyder3 Pro software had plus a few extra software options for an additional charge.
The basic setup was that the Spyder3 Pro software drew an outline of exactly where it wanted the Spyder3 hardware sensor to be placed in the centre of my computer monitor. I could try using the provided suction cup to hold it in place or hang the Spyder3 hardware sensor by the USB cable up and over the top of the monitor with a counterweight behind the monitor. Tilting the top of the computer monitor backwards caused the Spyder3 hardware sensor to rest flush up against the screen.
When everything was ready the Spyder3 Pro software flashed a lot of different colours and patterns on my computer monitor. It was similar to what I had seen when running the Apple Display Calibrator Assistant. The big difference was that instead of having me sitting there viewing and responding to each new image the Spyder3 hardware sensor was now doing the viewing and interacting with the software. At the end of the software run a new display profile was created that appeared in the list of display profiles on my computer.
The Datacolor documentation warned that different lighting conditions in the room such as sunlight coming in a window during the day versus light bulbs on the ceiling at night might require different display profiles to be calibrated. I do not remember the details but the Spyder3 hardware sensor could be used to measure the ambient light in the room at different times during the day and night as you were working on your computer.
Please be advised that this description is what I remember of my experience using the Spyder3 sensor and software about eight to twelve years ago. I have just done a quick Internet search and found a consumer product review website dated January 2008 with many photographs of Spyder3 being tested. Datacolor then released the Spyder4 version in 2012 and a few years later the Spyder5 version. Now they are selling the SpyderX version. Before purchasing I would recommend that you visit their website and check all of the details because I have no idea how they may have changed their product over the course of time.
Footnote
It is now 2020. I just tried running the Apple Display Calibrator Assistant as described in Level Two up above on an Apple Macintosh iMac computer. I was totally disappointed. They have dumbed the program down to the point that any pigeon, monkey or other animal could run the program without making a mistake. It was nothing like the program I ran years ago where my eyes got sore looking at too many test patterns trying to detect the slightest changes in colour as I calibrated the screen display.