Apple CMF (Color-Matching Functions) 2026

Apple CMF 2026

Apple has recently released their new Studio Display and Studio Display XDR, two 27-inch 5K Retina displays available with their signature $400 stands. We'll cover some display and colour measurements below, but a notable release alongside these displays is the new "Apple CMF 2026".

Unless you're really into displays and colour, or need accurate displays for your job, then you likely don't know what "Apple CMF 2026" is or why it matters. We'll cover the basics of the concept here while keeping it high level, as well as linking out to some very technical and 'from the bottom up' resources. We also have our test results from performing luminance and colour testing on the displays.

What is a CMF?

A CMF is plural, standing for 'Colour Matching Functions'. It is a set of mathematical functions that represent how the human eye perceives the colour of visible light. The first CMF was the CIE 1931 CMF, developed experimentally in 1931 by showing a collection of people different sets of colours, and asking them to adjust the input colour components until the final results 'match'. Like balancing a scale, but with colours.

The goal is to create a set of functions that can take the 'raw' input data of a light/colour sensor pointed at a display and calculate values to represent how a human will perceive it. In theory, if the numbers output by the measurements(and CMF) of the displays match, then humans looking at the displays will also say that they match. If the functions don't properly model the response of the human eye, then measurements of two displays could generate matching output numbers, but actual humans viewing the displays will experience mismatched colours.

Why are there multiple CMFs?

Despite the CIE 1931 CMF showing some serious staying power nearly a century later, there have been modifications and revisions released for this CMF(like the Judd Modifications), as well as introductions of entirely new CMFs(CIE 170-2 2015 CMF). These have stemmed from people comparing two displays that have been calibrated using a previous CMF, but finding that they still look slightly different. This suggests that the CMF used isn't accurately modeling how humans are perceiving the colours.

The main target of CMF improvement haas been more correctly modeling how the human eye perceives 'narrow-band sources' like can be found in modern LED, OLED, and Quantum Dot displays. These narrow-band sources produce a different than previous display technologies. This can expose weak points and inaccuracies in the models. Hence the need for new CMFs.

There has been debate about whether or not some of these newer CMFs are actually better, or better enough to warrant the entire world of calibration and measurement to switch from the ubiquitous CIE 1931 CMF. The main goal of calibration is to standardize the colours and light that everyone is seeing, so having multiple 'conflicting' standards is counterproductive.

Apple CMF 2026

On the surface this seems like 'classic Apple making their own standard', but Apple is working with CIE to develop this new CMF. They are also partnering with calibration and measurement vendors to integrate this new CMF into their tools. We must acknowledge the naming which prominently features Apple’s branding, but they appear to be engaging with the relevant authorities and stakeholders to deploy this.

The first release of the Apple CMF 2026 and accompanying calibration workflow actually still uses existing CMFs as the first step of the calibration procedure, only then using Apple CMF 2026 for white point. This still assists in achieving consistency between images displayed on different displays, but will not change the overall coverage of the colour spaces.

Notably, Apple CMF 2026 is only used on the Apple XDR Display (P3-2000 nits, and P3 + Adobe RGB-2000 nits) modes. All other reference modes are based entirely on the CIE 1931 calibration space, maintaining comparability to non-Studio Displays and their calibrations.

Resources

If this has ignited curiosity then I suggest you explore some of the resources below to delve deeper into the derivation, math, and peculiarities of colour spaces.

Color Spaces- Bartosz Ciechanowski - Brilliant interactive demonstrations of the concepts.How the CIE 1931 RGB Color Matching Functions Were Developed from the Initial Color Matching Experiments- Yuhao Zhu - Summary of the development and derivation of the CIE 1931 CMF.A Beginner’s Guide to Colorimetry- Chandler Abraham - Explores the transformations between colour spaces.

Studio Displays

With the launch of these two Studio Displays there has been a video produced on the ShortCircuit channel covering them both. It covers the main features and results of the monitors, however, we didn't have the time to present all of the results that we measured.

Those results will be presented below for your own reference and analysis, along with some summary analysis of our own. This is primarily a repository of data for those who know what information they are looking for, and how to analyze it.

Apple Studio Display

For the Studio Display (non-XDR) we tested the Apple Display(P3-600 nits), Digital Cinema(P3-DCI), Photography(P3-D65), and Internet and Web(sRGB) display modes with a window size of 1%. The Studio Display (non-XDR) does not have any display modes that use the Apple CMF 2026.

We did not conduct High Dynamic Range(HDR) tests on this monitor as it does not have Full Array Local Dimming(FALD) and it is not able to achieve appreciable HDR.

There was some off-axis tinting(pink horizontally, green vertically), as well as minor vignetting at the edges, but it was prominent only in challenging low brightness conditions. We found the text clarity to be up to Apple's usual Retina standard.

Luminance & Contrast Ratio

This display doesn't have any local dimming and we measured a roughly 1100:1 contrast ratio for the P3-D65 and DCI-P3 modes. This is slightly better than the roughly 1000:1 that is seen for most IPS displays, but still fairly standard.

The luminance of the display was consistent from 1% to 100% windows, for all modes tested. They achieved the results below, with the brightest mode being the standard "Apple Display (P3-600 nits)" mode which achieved Apple's claimed 600 nits.

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Apple Display (P3-600 Nits)

Grayscale and Gamma Tracking

The standard display mode has a minor cyan tint, and there was some poor gamma tracking to the target modes. Poor gamma tracking can cause inaccurate brightness in the shadows, either tracking too bright or too dark, depending on the target colour space reference.

The P3 display modes tracked slightly brighter than intended across the spectrum, but this should not significantly impact colour accuracy. The Photography mode presented a fairly neutral tint (albeit slightly yellow) to the display while the DCI-P3 reference mode seems to mimic the required green tint defined for that standard.

The Internet & Web sRGB mode tracks fairly well to the sRGB curve, only presenting slightly brighter than intended from the midtones to highlights, but shouldn’t harm colour accuracy much. Much like the Photography P3 mode, we have a fairly neutral tint (slightly yellow) to the display overall.

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Apple Display (P3-600 Nits) Targeting Internet and Web (sRGB)

Colour Space Coverage

The Photography P3-D65 and Digital Cinema P3-DCI display modes achieved 98.4% and 97.5% of the P3 colour space in our testing. These are better than the Apple Display mode when targeting those specific colour spaces, but the blue primary is coming up a little short and limiting coverage.

It’s a bit odd that the two P3 reference modes aren’t measuring the same coverage. P3-D65 and P3-DCI share the same RGB primaries so the labeled reference modes should have the same chromaticity gamut. Although the two colour space references differ in other char