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Reflecting the Real World: The Quest for True HDR

HDR bayou
(Image credit: Larry Thorpe)

From the mid-1970s to today, the television and video technical community have wrestled with how to best increase the overall quality of moving pictures. This work moved slowly over the extended era of analog video, sped up with digital “standard definition” video (SDTV) and made a significant leap with todays’ digital “high definition” video (HDTV). More recently, the upstart HDR technology nudged aside the preoccupation with advancing resolution and has slowly garnered the attention of both the theatrical motion picture industry and the multi-service television industry.     

Achieving High Dynamic Range lies in the understanding of how three key elements—displays at one extreme and camera sensors, lenses at the other—cooperate to create what is ultimately delivered to screens and audiences. Control and mastery of these elements are imperative in capturing and maintaining the full dynamic range of your content, helping unlock the full beauty and potency of HDR. 

DRIVEN BY DISPLAYS

The initial impetus for HDR was driven from the display end of the system. A decade ago, it was the striking advances in diverse display technologies that triggered worldwide interest in flanking the march to 4K and 8K standards for television production with considerations of wider color gamuts and higher dynamic range. LCD, plasma and OLED technologies were all expanding these imaging capabilities beyond that of the long-established CRT. 

The first footprint in HDR image capture is the glass. Optics are not always understood as the gateway to HDR, but it all starts with lens art and science. Optical designers are researching and iterating on lens science now that HDR is fully embraced and here to stay. They are working on inherent challenges that lenses bring to the format, such as achieving the desired deep, rich blacks while simultaneously doing justice to scene speculars. 

Adding to the complexity, but offering many opportunities, is the fact that filmmakers now have more lens options to choose from than ever before. And this choice should be deeply considered if achieving true HDR is the goal. At Canon, we realized that we needed to double down on our efforts to help ensure that our lenses were on the same trajectory as our cameras in terms of capture. Now that international standards for HDR have been established by the ITU, we will continue to innovate. 

The sensor is perhaps the first thought and highest area of focus when shooting HDR. Significant technological advances in recent years continue to drive the prevalence of HDR. Canon recently introduced the Dual-Gain Output sensor in the EOS C300 Mark III and EOS C70 cameras, offering more than 16+ stops of dynamic range. The dual gain nature reflects the bi-directional nature of HDR. One gain prioritizes saturation—protecting detail in highlight areas—while the other exposes important detail in the shadows while also suppressing noise.

AGILITY AND FLEXIBILITY

With HDR TV units expected to top 12.8 million by 2021, momentum for HDR among consumers will continue. But what about for cinematographers? 

While HDR standards for production are firmly in place, the challenge for cinematographers and colorists is that HDR standards for home displays are disparate, so agility and flexibility need to be baked directly into the tools. 

That brings us to displays. In the past, LCD displays have not been preferred by colorists because they lacked the deep rich black reproduction of other display technologies. However, recent technological developments in LCD displays have been nothing short of remarkable. In Canon’s 4K reference displays, we have incorporated multiple electronic tools to aid the optimum exposure settings in the cameras. Modern panels come equipped with engineering toolsets and functions designed specifically for HDR image review and user flexibility such as waveform and vector scopes, as well as legacy camera functions such as focus peaking, zooming, timecode, audio metering and histogram display. Recent features that have made their debut on modern reference displays include scalable false color monitoring, SDR/HDR compare view, pixel-level value checking, screen capture directly to USB and remote display operation via LAN or Wi-Fi.

Lastly, the elephant in the room is the current state of the world. It has made us all into remote workers, and we can expect continued delays in getting everyone back into studios and professional spaces where HDR workflows are possible. We anticipate that this will accelerate the introduction of even more tools to help make HDR content easier, cheaper and faster to produce from home in the near future.

Larry Thorpe is Senior Fellow, Imaging Technologies and Communications Group, Professional Engineering and Solutions Division for Canon USA.

To get a more in-depth perspective on HDR, click here to read Larry’s white paper on the subject.