It was rewarding to see a special shout out given to Light Iron New York’s Megan Marquis for debunking a team of clients’ initial fears of HDR, by walking them through the pipeline.
Higher Ground – A Producer’s Guide To High Dynamic Range (HDR)
June 9, 2017
Source: Produced By Magazine
Written by: Debra Kaufman
When PGA member producer Declan Baldwin signed on as line producer for the pilot of Amazon’s Z: The Beginning of Everything, he learned he would have to deliver an HDR master. “I didn’t really understand what it was,” he says. “Our initial reaction was, ‘That sounds complicated.’” Because currently only Amazon and Netflix routinely ask for an HDR master, most producers have no experience providing one and likely have a tenuous grasp on what it actually is.
Baldwin quickly got an education in the basics from Amazon post-production head Aaron Lovell, who walked him through the pipeline. Next, he made a stop at post-production house Light Iron, where executive director of business development Megan Marquis, spelled out what Baldwin and the crew needed to do. “She took the fear out of it,” he says.
HDR, the abbreviation for High Dynamic Range, provides more contrast in the image, producing whiter whites and blacker blacks and resulting in more detail in highlights and low lights. Wider color gamut, which is paired with HDR, offers many more and more saturated colors. Together, the look has been described as three-dimensional and very real.
Is anyone watching HDR? Producer Erin Smith, when faced with delivering an HDR master for Man in the High Castle, recalls the team was skeptical if anyone would actually see it that way. Roundabout Entertainment senior color scientist, Jerome Dewhurst, says we already do. “We’re now seeing consumer displays, whether they are computers, phones or tablets, that are significantly brighter and show a wider color gamut than the professional reference monitors used for Standard Dynamic Range (SDR) video mastering,” he says. “Arguably we have HDR displays already in circulation, but we’ve been watching SDR-mastered content on them.”
Produced By spoke to producers, cinematographers, a colorist and two color scientists who have shepherded HDR projects to completion. This is what we’ve learned.
Start in Pre-Production
Dewhurst points out that, “From a producer’s perspective, it is possible to start thinking about HDR before post-production. For example, if you’re shooting with an ARRI Alexa, using an HDR monitor on set, it allows you to better visualize the dynamic range the camera inherently captures more clearly than can be done with conventional SDR displays.” When Smith’s team first talked about HDR, she says, “We were in a bit of a conundrum as to how it would work, how much it would cost and how people would see the benefits.” First stop for her was the post houses where she saw HDR images which “blew us all away”—and started planning ahead.
Cinematographer Tobias Datum, who shoots Mozart in the Jungle, learned he would deliver an HDR master and asked to shoot with the ARRI Alexa. “The color science is superior,” he says. “The emphasis was on having 4K resolution, but I found the resolution isn’t as key to the look of the image as color and dynamic range.” He also spent time in pre-production with Technicolor senior color timer Timothy Vincent, who had already had a lot of experience finishing HDR masters.
Vincent says that it’s not uncommon for producers or cinematographers to ask about HDR during pre-production. “They are trying to get their bearings on a new delivery and what they’ll need,” he says. His advice: First, because HDR shows more details, the cinematographer has to pay close attention on set to what’s outside the windows. “In SDR, the windows are usually blown out, but not in HDR,” says Vincent. “The results can be terrible if, for example, you see out the window and it’s a different location or time period.”
Cinematographer Tim Orr, who shot the pilot for Z: The Beginning of Everything, agrees. “I had to be more aware of the highlight detail,” he says. “Since it’s a period show, if there were elements outside the window that we didn’t want to see, I couldn’t depend on blowing the window out. I just had to assume that if I could see it with my eyes, I’d see it later.” Orr’s observation speaks to Vincent’s second piece of advice. “Look at the RAW footage more often, especially if you have things you don’t want to see outside the window,” says Vincent, who adds that he doesn’t think there’s a need for an HDR monitor on set. “If you see it in the RAW, you’re going to see it.” [Editor’s note: Many producers use RAW as a shorthand description even when the format is not technically RAW footage. e.g., Amazon’s series store their data as LogC format (see sidebar) in ProRes 444 at 12 bits.]
At Technicolor PostWorks NY, CTO Joe Beirne advises a production to account for HDR in the aesthetic planning for the show, involving the director, cinematographer and scenic designer. “Ideally, you would do hair and makeup and camera tests through both the SDR and HDR pipeline,” he says. “I would try—in a modest way—to find a way to allow cinematographer and DIT to review HDR on set or at the color facility during the shoot. Where possible, take versions of the cut as it evolves and “flip” it into HDR space, just to put eyes on it. At a minimum, as early as possible in post finishing, start looking at HDR, even if there is no HDR master (yet) on your delivery schedule.”
Shooting an HDR Master
The main requirement for an HDR master is a camera that can shoot RAW or LOG footage. Such cameras include the Sony F65 and the RED ONE, though the most frequently used is the ARRI Alexa, which was utilized on Amazon’s Mozart in the Jungle, Z: The Beginning of Everything and Man in the High Castle among others. ARRI CEO/President Glenn Kennel notes that the ARRI Alexa cameras have always captured HDR, with 14.5 stops, slightly more than film captures. “Every Alexa camera is HDR ready,” he says. “HDR is about getting more out of the camera and allowing creatives more range to work with.”
“ARRI believes that HDR is a game-changer in terms of delivering higher quality TV programming,” he adds. “It’s much more impactful than going from HD to 4K. It allows the creative people to take the dynamic range they were already capturing and move that from the set to the screen.” Cinematographers, for example, enjoy the extra creative possibilities of being able to capture HDR and its wide color gamut. Datum reports that the third season of Mozart in the Jungle starts in Venice, Italy on an overcast day. “In the HDR version, there is so much more definition and gradation in the clouds that the image feels almost three-dimensional,” he says. “It brings out so much more texture, especially in the highlights. There’s a lot of dynamic range, which looks spectacular.”
Dailies during production become especially important. “I always advise producers to do a test, taking first-day dailies and timing selects in SDR and HDR,” says Vincent. “Then they can know right away what they’re dealing with.” Producer Baldwin notes that, “Most cinematographers, at least the ones I worked with, are excited about shooting in RAW.” As a producer, he says, he always wants to know the value for the storytelling. “I’m a fan of the format that best serves the film, although we defer to filmmakers,” he says. His caveat is that shooting data-rich RAW footage resulted in higher costs for storage cards, as well as somewhat greater effort to back it up. But Baldwin understands the rationale behind HDR; Amazon, he says, is “thinking about the future.” As people see HDR images, they become converts. Producer Smith reports that her post producer liked it so much that he now has an HDR monitor at homeand “absolutely loves it.”
HDR in Post
Although most of the post-production focus for HDR is in the color correction suite, Technicolor PostWorks’ Beirne has seen how HDR impacts the way edits read. “Your attention doesn’t always carry through the cut in the same way in the HDR grade,” he says. “In a traditional Hollywood style of filmmaking, the edits are meant to be invisible. An HDR finish ideally doesn’t change that, but your eye may be drawn to an unexpected part of the frame as the scene dynamics change.” The solution, says Beirne, is always to be “sensitive to the cut.” “Higher dynamic range, both within the frame and within the sequence, gives increased power to the filmmakers and adds additional scope to post,” he says. “It’s both a challenge and opportunity to do more perceptually. Account for HDR throughout the process and everyone will benefit.”
Whether the HDR or SDR master is created first depends on the flavor of the HDR master being created. For Dolby Vision, the colorist starts with HDR, says Vincent, and if the end result is HDR10, he starts with the SDR version. Vincent says he prefers to start with SDR “because most people are watching the SDR version. You can do two independent grades with independent color decisions,” he says. Beirne believes there is merit in both approaches. “But when you have a chance to do the HDR grade first, we found that we learned a lot and were able to carry that through into the SDR version,” he observes. “If you do the HDR grade first and it’s carefully accounted for by everyone in the process, the creative vision of the project is established there.”
Occasionally, a project gets an HDR master after the fact. That’s what happened to Manchester by the Sea, acquired by Amazon, which then ordered an HDR master. Cinematographer Jody Lee Lipes had shot in RAW, thus “banking” a potential HDR version later. Neither Technicolor’s Vincent nor Declan Baldwin (a producer on Manchester as well as Z) wanted to create a version that felt dramatically different from the SDR version; this movie was a case when HDR’s eye-popping colors were not appropriate. “My philosophy is that whether you watch in SDR or HDR, you should get the same emotional response,” says Vincent. “HDR is a heightened version, but it doesn’t have to feel heightened. I will dial it back and keep coming back until it feels the same.” [Editor’s note: Manchester by the Sea was colored at Technicolor-Postworks NY by colorist Jack Lewars.]
Despite first-time concerns over the creation of an HDR master, Smith says her experience was “pretty smooth sailing.” The only major change, she says, was “doing the two frame-by-frame color timings,” adding “that requirement might change in the future.” Although Baldwin still has misgivings about the necessity of an HDR master, if it’s a requirement, “embrace it fully and turn your attention to the experts.” After all, he notes, “There are many post houses already doing it. It’s quite manageable and really not that scary.”
Beirne provides an analogy. When archaeologists discovered that the classic Greek marble statues had been painted, artists such as Rodin thought it was impossible. “They thought of the white marble as the beautiful thing,” he says. “But those great marble sculptors painted the statues to make them look like people. People have felt that HDR was like painting the marble—that it isn’t really necessary. But what we’ve discovered is the opposite. In many if not all cases, it’s the highest quality you can get. To have this really rich original has turned out to be very important.”
High Dynamic Range has been captured for years by film and by an increasing fraction of digital cameras. With HDR, images can be displayed brighter and show more detail in both shadows and highlights at the same time, resulting in an image much closer to what human beings actually see.
Wide Color Gamut, although distinct from HDR, comes paired with it. As the term suggests, it offers a greater range of colors, covering a wider spectrum with greater saturation. SMPTE Rec. 2020 covers a wider color gamut than either Rec. 709 (Standard SDR TV) or P3 (current Digital Cinema.)
Dolby Vision is a proprietary version of HDR that differs by using dynamic metadata to “talk” to a Dolby Vision TV set and automatically adjust the content to the appropriate light levels for that display. This HDR version also specifies 12-bit color depth and allows for a peak brightness of as much as 10,000 nits. (A standard SDR TV is calibrated to 100 nits.)
RAW footage is unprocessed data directly from a camera’s image sensor, with no video processing.
LOGC fORMAT is a format similar to RAW, which appears without a display LUT (Look-Up Table) applied to it. It’s a very robust format, with uncompromised dynamic range, often favored by producers for TV workflows, due to its file size being considerably smaller than that of pure RAW footage.
HDR 10 is an open standard, created by a consortium of device manufacturers (including Sony and Samsung) to work around Dolby’s proprietary system. It supports 10-bit color and is generally mastered with a peak brightness of 1000 nits. HDR+ is an initiative of Amazon and Samsung, incorporating dynamic metadata into the HDR10 open standard.
HLG (Hybrid Log-Gamma) is another HDR flavor, this one created by the BBC and NHK and intended to support HDR in live broadcast. It uses the traditional gamma response of television for the lower end of the tonal scale and switches to logarithmic encoding for the brighter part, and so has some compatibility with existing production and consumer equipment.
PQ Curve—The Perceptual Quantization curve draws on research into human contrast sensitivity and attempts to make most efficient use of available bit precision to avoid noticeable quantization artifacts in an encoded HDR image. Both HDR10 and DolbyVision encode HDR images in PQ values (SMPTE ST 2084.)