A proper hardware device by Blackmagic Design (BM for short) and a calibrated screen has been the iron law for any professional user of DaVinci Resolve (DR for short). But for all those working under MacOS, this may have been valid for the longest time. We are looking at recent changes in DR for those without one. Spoiler: calibration still matters!

How to check

To see what’s going on when playing your movie on other devices and players you can compare your own footage, for sure. At least, if you were the colorist, you should know how it should look like. But if you are unsure (and our memory for colors can be tricked easily), there is the classic SMPTE chart in DR, which has the so-called PLUGE pulse (short for picture line-up generation equipment) in the lower right. In the wider black bar there are two narrow zones with a value just above black, the left one being the darker one (check your waveform).

If your blacks are not crushed by a false gamma interpretation, you should be able to see the right bar just faintly inside the black stripe. The middle one may only become visible if the shadows are lifted too much. Of course, it all depends on your screen too. If it’s not capable of showing black or at least near black, the rest of that whole area will not be pitch black, making it harder to judge the subtle differences. Actually, there is a third bar to the left of the two, but that is reaching down into the sub-black area and only visible if you have exported the file with “Retain sub-black and super-white data” activated. Normally it is just cut off.

Calibration options

DisplayCal is plugging into DR and sending its test patches through the grading software over any compatible I/O device to the screen you need to calibrate. The resulting LUT can be copied into DR and used as a monitoring LUT to correct deviations of the connected screen. This approach works absolutely correctly with the right settings in DisplayCal, being able to avoid any interference of the operating system, be it MacOS, Windows or Linux. Final precision is limited only by shortcomings of your monitor, like weak shadow areas, as visible below. BTW, those small spikes and minor shifts in the waveform are caused by compression in our recorder.

In our series of articles for those not able to spend a fortune on high-end solutions, we have shown how to get a proper LUT with the help of free software and second-hand hardware for Apple silicon. But now we have two solutions pretty much on par regarding calibration in the operating system by an ICC profile. So, we wanted to know if one can live without such an I/O device and that perfect calibration over the whole chain. Actually, BM has recently changed how preview windows and full screen display color and contrast. So, ICC profiles may not be insufficient any more for DR on a Mac with a screen adhering to standard!

Direct monitoring

BM has supported the use of Mac display profiles in DR’s viewers under MacOS for quite some time, even in 10-bit. But due to peculiarities carried over from older systems, they needed to use a non-standard version of Rec. 709, called 709-A. That was nothing but a crutch, and it was not only Apple’s fault that contrast and brightness were inconsistent between many players and other devices. If you are seriously bored, you can read this thread, with over 20 pages, the longest one ever in the DR user forum. You can follow some true experts and many wannabes there, discussing a ‘final’ solution. So, what’s our take on it?

The Never Ending Story: Are Apple XDR devices suitable for reference use in colour grading?

The main problem is lack of timely standardization when everything went from tubes to digital cameras and screens. The Rec. 709 standard for HDTV was defined based on analog technology, which behaved differently from modern cameras and screens. The newer addition to that standard is called BT. 1886, but it was only published by the ITU in 2011.

At that time there were already too many digital technologies in use, and most manufacturers didn’t really care much about adherence to a standard coming so late. BT.1886 defines a gamma (a contrast curve) of 2.4, which is fine for viewing TV in a rather dimly lit living room. Adjusting that curve is not really adhering to the standard, but on this model of a TV, for example, a value of +2 will get it to 2.2.

This slightly older Samsung TV, as a typical example, is offering modes like Movie, Natural, Standard, and Dynamic. Nothing says “Rec. 709” or “BT. 1886” right away, but „Natural“ is actually adhering to BT.1886, even fixed to it. „Standard“ is BT. 1886 too by default, but allows you to override that gamma in the expert settings – go figure. “Movie” is also adhering to BT.1886, but with a very warm tint – which again can be overridden, just like gamma. Recent ones have the “Filmmaker” setting, which is supposed not to change anything, and “Dynamic” is for bright rooms. Have fun with all the creative names and options of other manufacturers!

A lighter and less contrasty gamma of 2.2 might be better in a brighter environment. Mobile devices in particular are watched wherever you go. Even if some can reach very high brightness values these days, details in darker areas of the image can get lost if the content was graded as 2.4. Encoding clips for social media instead of movies for cinema buffs may profit from a gamma of 2.2, which is correctly flagged as 1-4-1 by DR. It even adheres to a standard, called BT.470 System M, as shown by MediaInfo (free). But this was a standard for analog television in some parts of the world only, and is now considered historical.

But do TVs and other devices really check such flags, which contain the information about encoding in your digital video files? They should tell the playback device which colour primaries, which colour matrix, and which gamma (called transfer characteristics here) were used. If you check with the info function for a video file on a Mac, the ones for Rec. 709 BT. 1886 are code points 1-1-1 or flags (I’ll use flag from here). They will be listed by cross-platform software such as MediaInfo as Rec. 709 for all three parameters.

In a perfect world, all playback devices and software players should respect such flags and show your video accordingly. Well, at least most of them assume your sources are 1-1-1, but often don’t care if it’s flagged as anything else, like 1-4-1 or 1-2-1. Some even force 1-1-1 on your clips, whatever they are. As we all know, YouTube is recompressing your sources, which is acceptable if the quality is good enough. But what’s absolutely unacceptable: whatever your original flagging was, YouTube will set it to 1-1-1 without even asking you! Just try to send one of your clips to YT and read it back. The free video patcher AMCDX by Alex Mogurenko will help you to correct wrong flags, but you need to remember the original encoding.

What to do?

In consequence, your results, which you encoded as gamma 2.2 for viewing in brighter environments, will actually be displayed darker and loose detail in the shadows. And if you encode from DR as Rec.709 gamma 2.4, which is offered as another option, it may too bright and lack contrast and saturation on players or a browser not respecting the flags. So, always encode as Rec. 709 (Scene) and hope for the best. It should look right on a TV with the correct settings. These can normally be found on most modern TVs or monitors if you dig deep enough into the menus, either as Rec. 709 or BT. 1886. Out of the box, many TVs are set to a very contrasty and saturated look, shouting out “Buy Me!” to the visitors of a mall for electronics.

The very popular VLC player is another example of ignoring flags, while we can recommend mpv player or its descendants for observance of flags. Of course, this says nothing yet about the quality of the screen attached to it. If that one is not calibrated, or at least set correctly in its menus, the image may still be far off. And then, there are all those image ‘enhancements’ imposed by digital TVs for viewing conditions, like bright environments or late hours. Or think of a projector meant to be visible in a not so dimly lit boardroom and optimized for (visual!) clarity of business charts.

Recommendations

Recent MacBooks and iPad Pro models have excellent blacks and offer reference modes for several standards, including HDTV (BT.709-BT. 1886). These are factory-calibrated and deactivate any image adjustments, assuming an environment properly lit for grading. Now, there is some sample variation and according to our own measurements, the nit value for white can be a tad low, like around 90 instead of 100 (some experts even suggest 120). Nevertheless, such screens come pretty close to a properly calibrated screen in the lower price range and offer much better blacks than conventional IPS panels.

If you are working for TV, we would still advise a professional, calibrated monitor via an I/O device. But, at least with the settings explained above, your viewers in DR will not look completely off when a client is looking over your shoulder. For all those working for social media, where your audience will have devices that you can’t control anyway, we suggest sticking to the only widespread norm: Rec. 709 with a gamma of 2.4. If you are concerned about visibility in bright environments, change the lighting in your room and check with an average smartphone, but avoid the setting for gamma 2.2 when rendering.

If you work for clients who want your results for social media, but are picky about how their movies look, you may need to supply them with an iPad Pro for presentations. Set it to a reference mode, block that, and try to explain to them why their average boardroom projector may look different. You may even want to take a photograph of TVs in an electronics market showing the same content next to each other.

Let’s do it on a Mac

So you’ve got a MacBook Pro (MBP for short) with Apple silicon and you’ve got a calibration probe, be it by Datacolor or Calibrite. But working just for the internet, you didn’t invest in an I/O device. We don’t care which generation of that laptop, as long as it has the nice XDR screen and reference modes. But who likes to work with DaVinci Resolve on such a small screen (even the menu bar is too short for all the little extras)? Let’s say you have a larger screen with decent color quality attached when you start grading at your home base. After all, not only Apple says that you should be grading to standards in a controlled environment – something hard to find in a hotel room or on the road. Now calibrate that external screen with your probe, and you’ll be generating just an ICC profile for the Mac in this case. More than one profile can be prepared for the correction of different monitors, which will be managed by the system.

Brightness according to BT. 1886 would be 100 nit, but 120 fits modern screens better. The steps needed for calibration are fully self-explanatory with the Spyder Pro software, and the result on a decent screen is very close to what we see on the MBP when set to reference mode. OK, DisplayCal may be a tad more precise. But it’s more complicated and taking many more measurements, resulting in excessively long lunch breaks.

You need to set the system preferences of DR to use the Mac profiles, as already shown above, and now you have to stick to Rec. 709 (Scene) on the Deliver page to get your output and its flags right. Do not use Rec. 709 Gamma 2.4, even if theoretically it should be the same!

Your timeline can be whatever you prefer: Rec. 709, ACES, or DaVinci Wide Gamut Intermediate (DWG). Of course, with manual settings your first node should get a CST (Color Space Transform) to adapt the incoming camera sources to DWG. Resolve’s automatic setting, called DaVinci YRGB Color Managed (aka RCM) set to SDR would also deliver the flags as 1-1-1, by the way. But you may need to check if the incoming footage’s color and gamma is identified correctly or needs to be set manually. That’s often the case if some difficult source has been transcoded into an intermediate codec, like ProRes, DNxHR, or Cineform.

Conclusion

In the end, you need to understand that rendering into a specific colour space and gamma is actually changing the visual content of your results. 
Tags are just metadata, which should trigger the right interpretation in players. That’s the point where chaos breaks loose, because manufacturers often don’t care for the tags and display your video based on assumptions. The only reliable approach is encoding to Rec. 709 with a gamma of 2.4 and having the tags set to 1-1-1, which is automatically done if you render into Rec.709 (scene).

The post LUTs, Tags, or ICC: Getting Colours Right in Resolve on a Mac first appeared on DIGITAL PRODUCTION and was written by Uli Plank.

Now that your I/O-Hardware should be up and running, let’s get into equipment for profiling the screen (aka calibration). Why do we need that? Well, until now, you were in a situation like making toast in your kitchen at home. You know that for your favourite brand of toast, you need a specific setting on your electric toaster to make it perfect. And what is the connection to colour grading? Well, if you visit friends and volunteer to care for toast, they may have another brand of toast and another toaster – two variables. Setting it to the same value as at home may easily burn your slice or leave it as pale as a ghost. “Profiling” your toaster with the right kind of bread may help…

Choosing an Instrument

Of course, you don’t use a thermometer to measure your screen’s colour, the typical instrument needed is called a colorimeter. A new one doesn’t come cheap, but if the screen you want to profile is not based on recent technologies like OLED or MiniLED, an older device bought second-hand or borrowed from a friend can be good enough. The popular brands for prices accessible to the average person have been Datacolor and X-Rite. The latter has by now re-branded their instruments for consumer level screen profiling to Calibrite.

The colorimeters by Datacolor are named “Spyder”, and the older ones were not really famous for their consistency among samples, as shown by our own experiences. And then, they used filters with organic colours until recently. Unfortunately, such filters degrade relatively fast over time. The better solution are dichroic filters, which last much longer, and are supposed to be used in the current Spyder X2 series. These are also supporting recent screen technologies, to which we’ll get back later. For further detail, see Jeremy Daalder’s Image Science.

The instruments by X-Rite came in two lines, the i1Studio/ColorMunki Photo, a spectrophotometer, and the i1Display colorimeters, and they have been using dichroic filters much longer. While spectrophotometers are generally more expensive and needed for printer calibration, they are not necessarily better for the purpose at hand. Their low-light sensitivity is less, so they can be slower for the darker patches. Since we are looking at you, cheapskates, we’ll focus on used X-Rite instruments, which can be found for decent prices.

This includes some re-branded ones, like the PhaserMeter from Xerox, which just looks like a ColorMunki Photo. What makes things a bit confusing: there’s also a ColorMunki Display, which looks like the i1 series and is actually a colorimeter. We have used one of each for this article, and both are a few years old. If you find one that suits your purse, you can even test it with a free software called i1Diagnostics. Something that can deteriorate in the ColorMunki are the reflectors to detect the position of the rotating part. It can be repaired by cleaning or replacement with aluminium foil if needed. As usual, you can find the advice for repair at iFixit.

Software and Installation

While you can freely download software for the X-Rite devices, which works even under recent operating systems and Apple Silicon, the devices themselves are the ‘dongle’ for this. So, the Xerox PhaserMeter, for example, will not work with the high-level i1Profiler, but is accepted by i1Studio. That’s a pretty easy to operate software with step-by-step instructions. But it’s not really the most precise kind of profiling, neither is it fast, and it will only generate ICC profiles.

What you really want for the use with DaVinci Resolve (DR for short) is a LUT for the monitoring path, which is not supported by i1Studio. Such a LUT can also be loaded into external devices, like LUT boxes, some monitors or TVs, and also madVR (for use as a player). There is an excellent open source software for this, called DisplayCal (based on Argyll). It had been a bit neglected by the original author Florian Höch – who can blame him, when so few donate? But thankfully, it has been resurrected as the “DisplayCAL Python 3 Project” by Erkan Özgür Yılmaz and Patrick Zwerschke.

We have used Version 3.9.14 under MacOS 15 Sequoia on Apple Silicon and it works fine for calibration, even if there are still some errors in the additional functions for analysis. It supports both instruments (and Spyders too). You’ll need to install Argyll (we used 3.3.0) and Python (here 3.13.2) too. Watch out: older versions of Python can crash DR. Scroll down to the installation instructions, the version for MacOS comes as a mountable DMG package you’ll only need to drag it into the applications folder. Apart from having Argyll and Python installed, you’ll also need to allow its use in MacOS with the command xattr -dr com.apple.quarantine /Applications/DisplayCAL.app.

Once you got everything arranged, we are going to tell you how to profile your screen with DisplayCal, together with test results from a cheap, but surprisingly good monitor.

Update on September 18th, 2025

Please make sure that you use the latest version of DisplayCal, which is 3.9.17 as of this day. There was a bug in earlier ones where the black point correction was applied even if switched off, which would make your blacks muddy.

The post Colour Monitoring for Cheapskates! Part 2 first appeared on DIGITAL PRODUCTION and was written by Uli Plank.