master test S
upposed you could produce a report which told an unhappy customer or a struggling lab technician exactly how accurate your monitor was. Could that have helped you win co-operation instead of denial, in your quest for good colour matching between original subject, digital image, screen display, prints and web uses? If so, then the latest neat little device from X-Rite could be your best friend. Learning that the i1 Display
Pro could assess ‘QA’ or consist- ency of a monitor, I asked to test it because I thought this meant it would test the colour consistency of the screen from corner to corner. My iMac 27 inch is great to use, but like many of its king has subtle den- sity and colour shifts across its huge field which are annoying. I was keen to find out if these were a result of my eyesight or a real thing.
But that is not what the i1 Display Pro kit does. By consist- ency, they mean the ability of the monitor to reproduce a set of colour patches accurately within a user-set DeltaE value (deviation, or error, from the perfect result).
The software comes loaded with a wide range of colour swatches of associated with graphic displays and colour printing, which include some subtle pastels and murky dark shades as well as the usual sim- ple tones you’ll find on a Mac- Beth type colour-checker. After you have profiled your monitor, it can be Quality Assured by measuring how well if reproduc- es the complete swatch colour by colour. You get see a visual representation with every square of colour diagonally sliced and the halves representing the difference. You also get a simple report expressing the overall accuracy of your screen, a green tick if it’s a within a DeltaE you can input, and a graph which can overlay readings and show changes. as you repeat the pro-
MASTER PHOTOGRAPHY 10
photography_
X-Rite’s i1 Display Pro measures colours the other monitor profiling devices can’t reach – and quantifies your results.
filing process. You can choose whether you reprofile every day, once a week, once a week or at random intervals.
What I found most valuable about the i1 Display Pro calibra- tion and ICC profile creation was the inclusion of a wide range of complex colour blends during measurement.
Many profiling devices meas- ure a large number of steps but use only R, G, B and grey lumi- nance. X-Rite i1Profiler software does not just read many steps for each channel, but measures the real-world palette of dozens of unexpected hues and tints as well.
The i1 Display Pro kit, above, is minimal – one device with USB cable and counterweight, one CD, one slim manual, contained in a software-size retail box. The device itself has a rotating diffuser seen below – upper left, in ambient light measuring position which also protects the lens; bottom, tripod mounted for projector calibration. The diffuser also acts as a stand for this use.
I have to say that the result is by far the best reprofiling I have had yet on the iMac 27 inch LED screen, using the i1 Display software’s auto- matic control of brightness and contrast functions which are difficult to set manually. I opted for 120 lumens, D65 and native contrast. The result was immediately apparent as a neutral, comfortable screen with accurate colours and no over-popping of reds or other saturated values.
The i1 Display device also has an ambient light measuring function so that it sits beside your computer (out of the way of light from the screen itself) and adjusts your monitor to compensate for changes in room lighting. This is not unlike Panton’s Huey Pro portable calibrator, which I did not find very accurate.
Camera style
At the heart of the i1 Display hardware is a huge lens. This is so different from the usual small measurement aperture. It looks like the front of an ƒ2 50mm Nikkor! This lens can be used from a distance, and when held 30cm away from your screen (by hand) is used to measure glare off the screen surface. There is a tripod bush in the base of the sensor, and
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