High Dynamic Range (HDR) is a film making technology that brings a much wider range of brightness to video, with sparkling highlights, detailed, nuanced shadows and incredibly realistic reflections. It’s the opposite of the kind of flat-lit, low-contrast images that it’s so easy to make by default. Without exaggeration, HDR brings video to life.

If you want to see HDR looks like, all you have to do is open your eyes. Nature is in HDR. The world is in HDR. Your living room is in HDR, and so is your local supermarket and the Grand Canyon. We don’t have to invoke a special “HDR” mode to see high dynamic range in our day-to-day existence: it just is.

There’s no exact definition of what HDR is or isn’t. As a rough guide, Standard Dynamic Range (SDR) tops out at around 6.6 camera stops. HDR begins above that, and it’s probably fair to say that HDR starts to really look different at around 10 or 11 stops, with 12, 13 or even more being typical for modern, professional digital cameras.

Atomos was very early to the HDR scene. We saw and understood the potential of this new medium. All our core products (Ninja, Shogun, Sumo, Shinobi and, more recently, Ninja Phone and Sun Dragon) are designed for HDR. What all our monitors have in common is our HDR software engine, AtomHDR.

The AtomHDR Engine

Consistency is everything with HDR, and with so many variables (cameras, sensors, video processing, monitors, etc.), we set out to take the best of affordable technology and—with very few compromises—give you the best picture we possibly can.

In technical terms, the AtomHDR processing engine processes the LOG output from a camera and transforms it into a tone-mapped preview of the PQ and HLG HDR standards to fit the capabilities of each of our products’ LCD displays. This, we believe, gives you the most accurate approximation of what the filmmaker is aiming for on your monitor or TV screen. This processing is analogous to what NLEs do when you want to view and edit HDR content on a non-reference-grade HDR display.

Atomos displays used in the latest Shogun line, as well as the Ninja and Shinobi products all use edge-lit backlights, which are excellent for reaching high brightnesses of 1000 nits and beyond but have the drawback that the darkest parts of the image can’t reach “pitch black” because the backlight will always need to be on when viewing an image.

One solution is to use Full Array Local Dimming backlights instead. Those can individually dim or crank up the brightness of zones arranged in a grid behind the LCD layers, thus significantly improving the contrast and dynamic range of the image. The biggest advantage of FALD over the edge-lit display is that “blacks” can truly be black because the LEDs in that area would turn off automatically, while the brightest spots of the image could be even brighter, as the LEDs in that area could focus on achieving a much higher peak brightness. But, and there’s always a but, FALD displays are expensive.

Alternatively, there is OLED technology, which is well suited to HDR because each pixel can be illuminated individually, thus reaching the highest possible dynamic range achievable on displays today. You’ll immediately notice the difference when putting a Shinobi or Ninja side by side with the latest iPhone displaying a image with a high dynamic range.

Again, the technology is not cheap, and a certain economy of scale is required to take advantage of OLED displays, which is why we’re starting to see them in top-end mobile phones. At NAB this year, Atomos launched the Ninja Phone, which is essentially a screen-less Ninja that clips on the back of an iPhone 15/16 Pro or Pro Mac.

This is the logical progression of our obsession with HDR. The AtomHDR engine continues to squeeze the best possible HDR approximation out of affordable edge backlit displays, but if you already happen to have a mind-blowingly awesome OLED display in your pocket, why not use that too?

HDR Is A Bigger Stage To Act On

With an HDR workflow, you literally start to see things in a different way. Think of your available dynamic range as a stage to act on. It’s not about physical space but the “space” or distance between highlights and the deepest blacks. Every set designer, gaffer, cinematographer and director knows this, at least implicitly.

In the pre-HD era, if you were shooting for a television drama for example, everyone involved in the production would gear their craft towards the capabilities of the television system at the time. That meant no massive areas of shadow, no shooting in near-dark and gloomy environments, no on-screen bright highlights, and tailoring colors to the limited range of the cameras. So that was a small stage, with a measurement of around seven stops.

Today’s stage is bigger, with more dynamic range, more colors, more scope for highlights, and vastly more ability to show detail in darker areas. That said, you don’t have to use all of that stage. And even if you don’t, you’ll still have a massively better time in post-production. HDR means you have more information for every level of illumination.

Light – And Color – Aren’t Linear

The natural world has such an extraordinary dynamic range that our digital recording systems don’t have enough numbers to allocate to all the color brightness levels. With an 8-bit system, you only have a maximum of 256 levels to describe all the shades of one of the three primary colors. That’s just about adequate for video shot on cameras that don’t have a huge dynamic range. It is possible to record HDR video using only 8 bits, but there’s likely to be an unacceptably wide gap between each of those 256 levels per color.

To improve matters, you can add levels and move from 8-bit video to 10-bit video. That helps a lot, especially when you realize that the total number of available colors is reached by multiplying all the available levels in each of the 3 color channels together.

That gives a very big number. But that’s not the whole story.

Light is not perceived linearly. You must keep doubling the amount of light to see a linear increase in brightness, which can lead to inefficient bits!

That’s because, by the time you get to pixels bright enough to represent highlights, you have to use a disproportionate number of levels to obtain the doubling in brightness. So, for example, if you’re at a brightness level of 64, you need another 64 values to double the brightness. At this point, you’ll need another 128 values to reach the next level of perceptible brightness. On the face of it, that’s a pretty absurd situation - as many as half the available brightness values are for highlights that you’ll rarely see. Meanwhile, you have only 128 values to represent every other level: the mid tones as well as the shadows.  

One way to improve this is to re-map luminance (brightness) values to the available bits. You can probably see that if you can make more use of the bits, say, from 128 upwards - making them available to pixels with lower levels - then you’ll be able to put more detail in the lower levels of illumination. It’s a compromise, but a good one. Essentially, this is what it says:

A very bright light is a very bright light. It’s not so important to be exact about it. But shadows are critical; if there’s detail in the scene, but you can’t make them out in the low levels of illumination, then by “borrowing” the bits that would have been used for the highlights, we can add to the visible detail in those low levels.

This is essentially how Cinema Log recording works. It’s an extremely effective way to cram a wider dynamic range into a smaller space.

The advantage is that you have much more scope when color grading. You can pull rich colors out of the mix while preserving more detail in the shadows.

Is there a downside? Yes. It takes a bit more work. You can’t watch Log footage without processing it because it looks washed out and unnatural. But (especially with Atomos), it’s easy to insert a LUT that will show accurate colors on an Atomos monitor. And the AtomHDR engine takes care of this.

The HDR Pipeline

Shooting & Monitoring In HDR

If you’re shooting an HDR production, you’ll need HDR monitoring at every stage of the process. Imagine trying to shoot in color with a black-and-white monitor (excluding black-and-white viewfinders, which are used only for focus and composition).

There is no such thing as an all-encompassing HDR monitor. No monitor is as bright as the sun. But with modern display technology, you can get close to the capabilities of typical HDR cameras - and then adjust your picture to approximate what it would look like on a domestic TV.

Lighting In HDR

You get a free ticket to HDR when you shoot outdoors. You don’t have to “create” HDR because it’s just “there”. But it does have to be carefully managed and, of course, all the usual lighting rules still apply.

Indoors you’ll need to manage highlights and shadows more carefully, filling in dark areas with reflectors, and working to create a satisfying image that matches your artistic intent. But you’ll have a wider dynamic range to work with, which means fewer worries about burnt-out highlights or losing detail in the shadows. There’s a much wider palette for you to work with. Atomos’ Sun Dragon lighting system has been developed specifically for HDR. It has 5-color LED arrangement for a natural spectrum and can be used conventionally or as a practical element in an HDR set.

Post-production In HDR

Dynamic range becomes an extra axis for adjustment in post-production. This new-found flexibility isn’t limited to “more” or “less” dynamic range. If you want more detail in the shadows, you can “stretch” that part of the luminance (brightness) scale. And don’t forget that HDR applies to colors as well as luminance. Each individual color in HDR has more headroom, meaning that you can achieve deeper, more intense colors than would be possible in standard dynamic range.

Conclusion

HDR isn’t a special effect: it’s nature; it’s the world. Filming and post-producing in HDR gives you a brighter window on that world. You can look through the whole window to get the brightest highlights or the darkest textures, or you can simply look through a small part of the window, knowing whatever you shoot will be faithfully reproduced and that you have much more dynamic range in reserve if you need it.

It’s never been easier to adopt an HDR workflow, with an ever-increasing choice of affordable tools available to shoot, monitor, manage and manipulate your work.

Shoot everything in HDR, and you’ll have the best possible footage for every kind of production. Even if you deliver in SDR, shooting in HDR gives you more flexibility in post and lays the groundwork for creating HDR versions in the future.