Is it necessary to use the Ambient Light Measurement when creating a profile?
When using a number of different monitor profiling solutions including1Display2, i1Pro, i1Match and ColorMunki the software may give you the option to take a measurement of ambient light conditions or the lighting values of your room. This is for informational purposes only and will not affect the final profile. With some programs users may be prompted what the most ideal luminance setting is for those conditions and can be extremely helpful in determining the correct settings.
Your surrounding environment influences the appearance of color on your color display. Bright ambient conditions will make your display look darker, with lower contrast. Lower-light ambient conditions will make your display seem brighter, with greater contrast. As a result, changing ambient conditions will change the way you experience the displayed image. This is how to judge what luminance you wish to see. That said, the industry stanard is 120cd/m however many professional photographers will bring that value down to 80cd/m for a closer match between the printed output and what they see on their screen. The best rule of thumb whether using the ambient light measurement or not is to work with your printer and experiment with what is working best for your workflow. Once you have these values established for the best match then you can use them in your regular profiling to get the most accurate repeatable results.