Colour Control in Video: The X-Rite ColorChecker

Today’s cameras record colour in such a way that, for ordinary purposes, the image needs nothing done to it. Even if you do take on the grade, you’ll usually make a few technical adjustments, perhaps some artistic or visual ones, and that’s it — the video is fine.

An example would be a situation where I wanted to talk about this blue-violet box. Everything will be fine until it becomes a product video.

It can easily happen that the client rejects a video like this, because their logo and corporate identity have a precisely defined colour. This one. And so they require the box in the video to look like this.

One small step for a man, one giant leap for corporate identity. That’s also why I’m holding a colour chart in my right hand. Today we’ll write a bit more about these tools.

Besides the nervous, neurotically pedantic client, you’ll also run into situations where you shoot with several cameras from different manufacturers. How do you match those images so they share the same colour rendition?

X-Rite has been offering a solution for years now. It’s a long-established industry standard. Before that it was the Gretag Macbeth ColorChecker. Today it’s the X-Rite ColorChecker, the X-Rite ColorChecker Passport and the X-Rite ColorChecker Video. (Passport means it’s a tiny chart you can carry in your pocket. The standard version of the chart is larger.)

These charts have precisely defined colours for each of the individual patches. If you film them, your editing software knows how to set the colour so that it matches reality as closely as possible.

Look at how differently three cameras interpret colour. Even though the lighting was identical and the white balance was set manually, discrepancies still appear in how each colour looks on each camera. For home use it doesn’t matter. The problem arises when you have to deliver a video that at least roughly matches the client’s colour requirements. And you’ll be pulling your hair out if you want to cut footage from these three cameras together. Jumps in colour like that are very distracting.

Your grading software will then show you immediately how the colour of a given patch on the chart should look (upper section) and how you actually recorded it.

A worse camera may look like this, and those are already considerable departures from the desired realistic colours.

Using a chart like this, the software can build something like a profile for each shot. Rather like applying a LUT or an ICC profile. Except you can create one for each individual shot while filming.

Skin tone, too, often lands automatically at fairly sensible values.

Another illustration of how you can use the ColorChecker Video.

I isolated the chart with the primary colours, and on the vectorscope we can see the marked targets showing where those colours ought to sit. (The vectorscope is set to 2× zoom — this chart isn’t that saturated!)

Ideally, then, it should look roughly like this. This is exactly how you can adjust colour manually during the grade. By eye you see how the image appeals to you, and by the measurement points on the chart you check whether the grade is objectively heading in the right direction.

Colour charts in practice

If all this is starting to appeal to you, let me cool you down right away. You usually won’t achieve sensible results in an 8-bit format. In other words: you can try, but colour calibration won’t always bring an improvement to the image. In ordinary shooting, charts will get different cameras reasonably close to each other fairly quickly, but you won’t get them to actually agree. I know you can find enthusiastic reviews online claiming that these charts deliver a complete colour match, but practice tends to be a little worse than the reviews of eager affiliates whose main concern is that you buy after clicking the relevant button. It depends on what scene you’re shooting.

Some dark blues, violets, neon yellows and pinks behave so differently across cameras (anyone who wants a headache can go and look up metamerism) that you’ll never fully reconcile them. Not, at least, in a timeframe that keeps the grade at a sensible price.
Certain lights (LED sources especially) can produce unusable results when working with these charts. Your fixture may still have a tag dangling from it boasting a CRI above 95%, but at least you’ll see how hard it is to simulate the light of a small star with a handful of diodes. At that moment the chart won’t help you. One camera may get attractive, realistic colour “at a click”, while another ends up with unusable colour after correction.
Besides the colour patches, the X-Rite Passport version has a white balance target on the other side — a precisely neutral colour. Very handy.
The X-Rite Passport Video version also has a third leaf for focusing. Useful! You’ll appreciate it when shooting from a tripod with a wide aperture and a long lens.

Worth it or not?

I always put these charts in my kit as a matter of course. They’re small and occasionally very welcome. White balance alone would be reason enough for me to carry one, but the colour patches sometimes help with the grade when I can’t get to the results I need quickly enough.

Before you start checking whether you have a hundred-plus to spare, try it out. There are dozens of videos and video reviews online with these charts in frame. Try downloading one and playing with it to see whether it makes sense for you.
If you haven’t missed it so far, you don’t need it.

And if you do buy one, which chart?

Let’s start with size.

The larger format is roughly A4. It’s unquestionably the better chart, because even at a distance from the camera it will still be large enough in frame. If you can manage to carry it, favour it — but count on it being unwieldy. It wears out quickly.
The smaller chart (Passport) is practical, but there are scenes for which it’s too small. For a smaller video production it’s probably the better solution. After all, you can have it at hand and pull it out of your pocket at any moment.
And one more thing: however stable the colours on these charts are, they aren’t eternal. Officially the charts should be replaced perhaps every two years or so, to be certain none of the colours have faded. That makes buying secondhand more of a risk than a saving. Even a small deviation of the individual patches from the standard will throw your image off.
Ah, and another thing: don’t try printing one at home. It won’t work.
Be careful buying from unofficial sources, such as assorted cheap Chinese webshops. If they sell you a fake, it won’t work properly.

On to the brand.

X-Rite is the industry standard today. You probably can’t go wrong there.
If your editing software can work with charts from another brand, you can use those. You can find charts that are somewhat cheaper, and ones that are far more expensive.

Let’s finish with which one.

As you can see, I’ve been using the same standard for nearly twenty years — my beloved Gretag Macbeth ColorChecker. To this day I remember the impatient agony of waiting over a month for it to arrive from the USA…

Well, yes. Back then I was about 35 years old and 35 kilos heavier… Today you can buy the same thing as the X-Rite ColorChecker in just about any video or photo shop. So which one?

On the left, the classic ColorChecker. On the right, its video version.

The classic ColorChecker is primarily intended for photography. I have the feeling I work better with it.
The ColorChecker Video has significantly expanded patches for calibrating skin tones. Its fundamental weak point is the glossy surface. If you shoot it badly, the result will be unusable — nothing on it may catch a reflection.

So I work with both charts. I film them at the same time and decide during the grade which one to use, or whether to use either.

In your editing software, the video chart can be used not only for colour calibration but also for checking exposure. The grey, white and black patches have their own numerical values, and if you use curves to place each of them where it should be on the vectorscope or in the histogram, you set the exposure to a kind of norm. You don’t normally need a chart for this — the eye is enough. But some scenes are very deceptive. In product video especially, it tends to be important to come close to the client’s requirements in both colour and tonality.

As a rule I shoot video in 8-bit, so I don’t exploit the full potential of these charts. More than once I’ve graded a video by taking part of the colour correction from a layer processed through X-Rite and doing the rest with a manually set grade. I like being able to choose for myself whether to take the colour from the chart, do it by hand, or combine the two.

In any case, the best approach is to have footage recorded so that its colour rendition comes as close to reality as possible. Today’s cameras have “natural” colour modes that already deliver excellent results. At least for those of us who remember the old days, that’s still refreshing. A few years ago, plenty of colours were problematic on most digital gear, and cameras were spitting out colour nonsense. That era is coming to an end. It’s quite possible that you have a good camera too, and that for ordinary video all you need to do is set the white balance correctly.