I've been asked how to sort-of calibrate the iMac in the absence of a colorimeter and dedicated software.
Whilst it is possible to do a pretty decent calibration using your eyes, there are a couple of caveats:
- you need a printer that is producing reasonably accurate colour prints
- a Spyder 3 Pro or Eye 1 Display 2 calibration tool will do a better more consistent job
- you will also need the free 3rd party utility "Shades", as the brightness of the iMac screen even when set at its lowest is still too bright.
Okay, now that the disclaimers are out of the way, the following method of calibration will result in what you seen on your iMac screen being quite close to what you print out. If you're using Aperture with soft proofing turned on, you can a very close match indeed.
Step 1 - Preparation
1. Download a printer evaluation image - I use the one at this link:
2. Download the Shades utility at this link:
Step 2 - Print the reference image
This is pretty straghtforward - print your chosen reference image onto your best photo paper, or the photo paper that you use most frequently, from the application that you would normally print from. If it's Aperture, for example, you'd print from within Aperture using a set of known good settings for the relevant paper.
Step 3 - Baseline Comparison
Examine your reference image - it probably looks quite a bit different to the on-screen image. A frequently reported situation is that the print is a lot darker than the screen. The colours may also be carrying a specific overall tint - too much yellow or blue. The plan is to adjust your screen so that the print and the screen are closely matched. Note down any apparent colour casts or poor colour renditions on a piece of paper.
IMPORTANT NOTE: Allow around 10-15 mins for the print to dry before doing the comparison - as the print dries the colours will change
Step 3 - Play with the Calibration Utility
1. Open your iMac Preferences
2. Click on the Display icon in the Preferences pane
3. On the resulting dialogue there are two buttons - "Display" and "Color". Click on the "Color" button.
4. In its default state there should only be one profile showing in the profile list that appears - select the "iMac" profile from the list box then click on the "Calibrate..." button
5. Welcome to the iMac Display Calibrator! Click on the "Expert Mode" tick box at the bottom of the dialogue then click on continue
6. Follow all of the steps for calibration - it's best if you squint slightly from around 50cm away to get a better judgement of colour densities and tints. If at any stage you're not sure about which way to adjust the sliders, look at your notes and the reference print to remind yourself what colour casts you're trying to fix.
7. Once you've finished, save your new monitor profile as something like "iMac Calibrated"
Step 4 - Installing Shades and Adjusting Brightness
1. Install Shades (I'm sure you can figure this bit out!)
2. Run Shades and reduce the brightness of the screen so that it is similar to the apparent brightness of your printed reference photo. Hold your photo next to the monitor to help - make sure your room lighting is in its normal state to ensure a reasonable comparison.
Step 5 - Recalibrate
Once you reduce the brightness to the desired level, you may discover that some of the colour balances are not quite right. Note the bits that are not right on your scrap piece of paper.
You now need to go back and re-do the calibration with this new information - but here's the gotcha: it seems that you can't properly do the calibration with the Shades utility on as the colour discrimination is reduced.
So, stop the Shades utility and open your recently saved profile again in the calibration utility. Using your notes, tweak the calibration sliders just a little, save the profile again, re-start Shades and do another comparison to the photo. You should be pretty close now.
Repeat again if necessary.
Step 6 - Know When to Stop!
Don't overdo it. Providing you've got a good reference image, you can probably get a close match after three iterations. Don't expect perfection.
I hope this is useful - I can't afford a calibrator so came up with the above method by trial and error.