Fifty Shades Of Blue
- By Adrian Pennington
DPs and crews wanting to maximise HDR’s potential need to ensure the nuances of HDR delivery are accommodated at every stage in the pipeline… By Adrian Pennington.
High Dynamic Range is part of the UHD specification and has arguably grown quicker than that of 4K resolution as a piece of the pie. HDR enhances the visual quality of any resolution format, broadening the range of contrast to ensure more picture detail along with higher brightness screens. Broadcast engineers and shaders, lighting directors and DPs as well as colorists need to know what they are looking at on set when capturing HDR which is where monitoring comes in.
“HDR offers a huge step up in image quality, especially when paired with 4K resolution,” says Simon Hall, Senior Technical Sales Specialist, Blackmagic Design. “DPs and crews will want to maximise its potential, but will need to ensure the nuances and subtleties of HDR delivery are accommodated at every stage in the pipeline.”
It can be a tricky balance. He adds, “A scene perfectly lit for SDR may look completely incorrect when checked for HDR. Monitoring is critical in achieving this, however cost can play a factor.
“Which colour gamut is monitored will depend on the deliverable file, so HDR formats can use either P3-D65 or Rec.2020. To have accurate HDR monitors throughout the production pipeline that show the EOTF ST2084 at a 1000 nit+ level could potentially be expensive.
“When it comes to delivery, HDR is a 10bit system, so it is recommended that files are recorded in 12bit to ensure enough colour volume and dynamic range for the delivered file. This rules out certain cameras and codecs, and 8bit sources, as unsuitable.”
HDR files have to be delivered in a specific format with the correct embedded metadata for the file to trigger a consumer display into HDR. Also it has to be either trim pass metadata, which profiles the image in an SDR gamut and gamma, or a separate grade for SDR has to be delivered.
Blackmagic Design offers a complete workflow solution for HDR. Blackmagic RAW is a 12bit file with colour gamut greater than the Rec.2020 profile. On-set monitoring and recording with Video Assist, which offer 2500nit HDR monitoring, with support for 3D LUTs and HDR scopes. DeckLink capture cards, UltraStudio playback devices and Mini Monitor offer external HDR monitoring. In post, DaVinci Resolve Studio allows for monitoring and grading of HDR content, and can deliver files for Dolby Vision, HDR 10+, HDR 10 and Hybrid Log Gamma files.
“Currently the biggest challenge for on-set HDR monitoring is a lack of affordable and set ready equipment that supports true 10bit and higher HDR,” says Colin McDonald, Product Manager Cine Products at Vitec Group’s Creative Solutions.
“Many of the current approved HDR offerings are incredibly expensive and physically prohibitive for on-set use. Additionally, since so many of the current offerings come from different manufacturers, there is no shared workflow experience. Creative Solutions is working hard to provide a complete end-to-end HDR solution for customers at all production levels.
Creative Solutions - which comprises brands Teradek, SmallHD and Wooden Camera - is rounding out HDR workflow with new releases like the Teradek Prism Encoder / Decoder, which is built for robust, high-bandwidth remote video streaming, supporting up to 4Kp60 10bit HDR. The Bolt 4K family of products support true wireless 4K HDR video transmission. Finally, the upcoming SmallHD Vision series of monitors will meet the DolbyVision HDR spec for monitoring, and standardise on-set HDR with a rugged and portable form factor.
Whether integrating HDR into a live production or monitoring HDR footage on-set, you’re often working with various camera and HDR formats, as well as SDR footage that must be incorporated into the final output or product.
“In live production, it’s essential to be able to quickly and easily convert between SDR and HDR, various HDR formats like PQ and HLG, and camera log formats,” says Andy Bellamy, Product Marketing Manager, AJA Video. “In an on-set environment, camera log formats must also often be converted to BT. 2020, ACES or other standards commonly used in postproduction. This helps to ensure that the integrity of the image is maintained as it moves throughout the signal chain. Without the right combination of technology, these tasks can tasks can prove difficult.”
AJA offers a range of solutions to address these needs, including FS-HDR with Colorfront Engine technology, which helps professionals bridge conversions between camera log formats and SDR sources to HDR formats, from SDR to HDR to bring non-HDR camera feeds and materials into HDR programming, and HDR to SDR in situations where SDR is a final deliverable - all in real-time.
“Our HDR Image Analyzer 12G waveform, histogram and vectorscope monitoring solution can also prove incredibly useful in giving production and post teams the confidence that HDR production and mastering are consistent and predictable,” says Bellamy. “For simpler on-set HDR monitoring needs, we also develop the Hi5-4K-Plus Mini-Converter, which enables professionals to feed HDR10 and HLG footage to cost-efficient HDMI displays.”
Flanders Scientific is introducing the XM312U as one of the world’s brightest commercially available professional reference displays. The XM312U is a 31” UHD resolution HDR and SDR monitor equipped with 12Gbps SDI inputs. The unit qualifies as a Dolby Vision mastering monitor. A peak luminance over 5,000cd/m2, support for both PQ and HLG EOTFs, multiple color gamut selections, and a contrast ratio in excess of 5,000,000:1 make the XM312U ideal for a wide variety of demanding HDR workflows.
“For HDR projects our industry is typically requesting either 1,000nit or 4,000nit deliverables from colorists,” says Bram Desmet, CEO. “Up until now our 3,000nit capable XM310K was one of the few solutions available that allowed colorists to grade well over 1,000nits, but it still fell a bit short of that critical 4,000nit deliverable threshold.
“With the XM312U, we set out to address that limitation and deliver something to our clients that can take them to that 4,000nit goal and beyond, while also offering some key improvements to other performance benchmarks. “We are excited to see what clients can do with the XM312U and what higher luminance mastering options will do for HDR content creation in the years to come.”
LogiColor is a newly developed colour management system aiming for accurate and stable colour reproduction on TVLogic monitors. According to the firm, it’s not just a new firmware with improved functionalities, but an “innovation inside the whole colour processing pipeline to control monitor colours.” It is based on the WonderLookPro algorithm and covers not only design and manufacture, but also customer support.
LogiColor is onboard TVLogic’s LUM-series monitors including the LUM-310-CI all powered by a new colour signal processing engine in 24bit linear RGB. It achieves correct calculation and flexible support for various colour standards, gamuts and EOTFs.
“In order to compensate the non-linearity of the display panels’ colour reproduction, a new processing method is introduced to achieve correct and stable interpolation. Thanks to this new process, the monitor uses the full power of the LCD panel more than before.”
The Postium OBM-X Series is the South Korean company’s most advanced displays for UHD/4K HDR Grade 1 and Grade 2 Reference monitoring. The 31” OBM-X310 is a Grade 1 monitor compatible with Dolby Vision, HDR10 and HDR10+, HLG and others. The 24” OBM-X241 is for QC and HDR production monitoring. Both utilize native 4096×2160 LCD panels with a maximum HDR luminance of 1000 nits.
According to Postium, the unique dual cell panel structure of the OBM-X310 allows for light output modulation at an individual pixel level. This panel structure eliminates pixel light leakage to adjacent pixels that often results in a “halo effect” and allows for uniform gradation of grayscale and colour with black level details that are “highly accurate and free from visible artifacts related to imprecise local-dimming pixel luminance errors.”
3D LUT import is supported for colour matching between individual displays as well as using customized ‘looks’ that have been created in third party color-grading applications. In addition, the OBM-X series has built-in Camera Log to Linear conversion LUTs from various camera manufacturers including Log-C, C-Log / S-Log2, S-Log3 / J-Log1 and more. The LUT-converted content can then be output to downstream devices/monitors via the SDI loop out.
“The single biggest challenge in monitoring HDR onset is the current limitations in terms of the panel technology,” says Wes Donahue, VP, Sales & Marketing, Eridita Marketing. “With HDR being based on Rec. 2020 colour space and demanding minimum and maximum simultaneous contrast requirements, there are very few technologies available that can render both the colour gamut and the contrast and luminance range required. No monitor can currently achieve all of the Rec. 2020 colour space. And only a few can handle the luminance and contrast required for true HDR.”
He highlights that Konvision has announced a new 31” OLED monitor - the KUM-3110S - that will reach more than 99% of DCI-P3 and 80% of BT2020. It has a max luminance of 540 nits. So, while it cannot reach the top luminance levels required for color grading, with a 1,000,000:1 ultra-high contrast ratio and 0.0005 nit deep. “It can reproduce incredible black details - which should make it very useful for on-set HDR monitoring,” he adds. The new OLED should be shipping in 4Q21.
In addition, Konvision’s KXM-3120QD is a mastering 8K monitor for a wide range of HDR workflows.
The 31” monitor has a dual-layer LCD panel which offers 1000 Nits brightness and 1,000,000:1 contrast ratio. Its equipped with 4x12G-SDI inputs and built-in HDMI 2.0 interface, quad link supports up to 4x 4K 2160 60P and supports various cameras’ HDR Log curves and SDR Log curves, S-Log, C-Log and Log C.
