The best way is get a device designed for calibration but....
.....with that said, the MAC provides an easy means to calibrate and is all I use.
Follow these steps:
Click on the blue Apple at the top left.
Click on System Preferences
Click on Displays
Click the COLOR button
Click Calibrate
...then follow the instructions from there. It may not be dead on but should be very close. It might require a couple of times to get it right but in the absence of something like a Spyder, it is the next best thing.
Once calibrated, you will have to send some prints to Mpix to see how close they match.
There is a huge difference between a picture and an
image.....I don’t do pictures." ~ G. Walters
Mamiya RB 67 w/multiple backs and lenses
Bronica ETRw/multiple backs and lenses
Lumedyne Flash
Canon 30D
Tamron 28-75Di II
Canon 80-200 F2.8L (Yes - 80-200)
Metz 58AF-C1 Flash
...and too much more to mention.
