How Accurate is the i1 Display Pro colorimeter, Anyway?

The X-Rite i1 Display Pro occupies a unique place in the color measurement world. It is by far the most popular colorimeter for display calibration. The reasons for this are clear. It costs only about $250. It is reasonably fast, it reads quite low (about 0.003 nits), has filters isolated from changes in heat and humidity, and its design includes a built-in tripod mount and color-neutral diffuser. There is nothing on the market as good as the i1 Display Pro for any where near the price. Arguably, its only shortcoming is shared by virtually all filter-based color analyzers. It lacks reference quality accuracy. Fortunately, this problem is easily addressed by using a software correction against a much more expensive and accurate spectroradiometer.

So, the question is how much correction is required? In other words, how accurate is the i1 Display Pro?

Since we have offered a version of the i1 Display Pro for several years that includes built-in corrections from a reference spectroradiometer, which we call the Display 3 PRO, we have been able to amass a large database of information (literally hundreds) about those corrections that allows us to accurately characterize the meter's accuracy. Let's start with a correction that we created just today.

CRT 6.39 2.01 0.15 0.62
Front Projection 1.06 2.13 1.09 0.77
LG LED LCD 1.61 1.52 0.48 0.71
LG Standard LCD 2.02 1.22 0.35 0.50
OLED 1.24 2.50 0.16 0.33
Plasma 4.61 2.40 0.68 0.80
Quantum Dot 4.95 2.63 0.16 1.22
Samsung LCD LED 3.90 2.03 0.30 0.91
Samsung LCD Standard 2.12 1.34 0.69 0.60
Sony LCD LED 2.15 1.34 0.40 0.61
Sony LCD Standard 1.93 1.57 0.58 0.61
dE values in CIE94

In many ways this i1d3 is typical. The largest dE values are for white, which average in the 2-3 range. The displays that the meter has the most difficulty measuring accurately are refresh displays, such as CRTs and plasmas and newer display technologies, such as Quantum Dot and LED from Samsung. For whatever reason, LG LEDs pose a smaller challenge to the i1d3, and Sonys fall somewhere in between. Interestingly, the i1d3 tends to measure OLEDs quite well. See below for detailed information about 14 additional i1 Display Pros for which I tabulated error data. The highest dE value for each meter is highlighted in yellow.

There are a few takeaways in this data.

  • It is clear that the i1d3's color accuracy exhibits considerable unit-to-unit variation. Look at meters 13 and 14, which are incredibly accurate. Then compare that with meters 3 and 9, which are not so much. It shows a dE variation of about 3.0, which is not trivial. One of the consequences of this is that meters 3 and 9 would greatly benefit from a spectroradiometer correction, even from an i1Pro 2. Any benefit for meters 13 and 14 would be negligible.
  • The i1d3 struggles when measuring Samsung Quantum Dot, and to a lesser extent Samsung LED, plasma, and CRT.
  • The i1d3 is the most accurate reading green and blue and the least accurate reading white and red.
  • Although the average i1d3 is less accurate than the i1Pro 2 and the worst considerably less accurate (not surprising), the best i1d3s are actually a little more accurate (very surprising).

Previous articles

i1Pro 2 Accuracy

Metameric Failure

Colorimetry Research CR-250

Colorimetry Research CR-100

X-Rite i1 Display Pro III colorimeter

JETI Specbos 1211

DVDO Duo Video Processor

K-10 Colorimeter

Lumagen LUT Color Correction

Sony 4K Projector