Astora Digital Builds HDR, Virtual Production Workflow Expertise in China with Help from AJA ColorBox

Across projects, Astora Digital’s team serves as the backbone of the production crew, functioning as a data and quality control center and applying state-of-the-art technology on-set to support the creative aspects of production. Their mission is to ensure smooth communication and collaboration across departments while seamlessly integrating digital and artistic creativity. For this, they’ve come to rely on a pipeline built with tools like AJA ColorBox, Io 4K Plus, KONA 5, HELO Plus, and Corvid 44 12G, plus significant technical expertise. 

Since SDR is still the primary deliverable in China, Astora Digital designed its pipeline to support simultaneous SDR and HDR production, including monitoring and adjustment. With an increase in camera setups, the team knew more equipment would be needed, making it a significant challenge for the DIT department in terms of stable operation and signal management in fast-paced shooting environments. Traditional products lacked support for high-precision LUTs, but AJA ColorBox, a compact, high-performance HDR/SDR converter, provided a solution. 

Commenting on the decision to use ColorBox, Color Manager Lucas Lin, noted, “Previously, we’d need to prepare several LUT boxes to process SDR and HDR signals simultaneously. With ColorBox, we only need one unit to achieve real-time SDR and HDR monitoring on a single line. It simplifies our workflows and makes the process more straightforward and manageable.”

Although Astora Digital tailors each workflow to the project, they almost always start with a Log C camera signal that goes through a 12G-SDI router to color grading. The AJA ColorBox Colorfront pipeline then supports HDR to SDR conversion, allowing the director and director of photography (DP) to monitor HDR and SDR simultaneously. Their capture equipment and routers are all equipped with 12G-SDI connectivity, including the main control-level monitors although on-site video transmissions remain processed at 1080p, 24 frames per second due to hardware limitations. 

Astora Digital provides sample processing at 4K or up to 8K HDR based on the original sources given. These samples are used for directors to review and DPs to assess results. Despite hardware constraints, their setup is designed to ensure high-quality output. The high-resolution samples that the Astora Digital team provides for review and guidance enable the creative team to make more informed decisions during the daily filmmaking process.

ColorBox is often also employed by the team to perform real-time color adjustments based on the camera output to achieve the expected color effects. Doing so establishes a strong foundation for post and contributes to maintaining color consistency, ensuring captured footage aligns with the intended visuals. Calling out the AJA Color Pipeline as a key advantage of ColorBox, Lin said, “The AJA Color Pipeline enables us to uphold color consistency across every stage of production, providing valuable support for cinematographers to supervise LED color control in virtual production work. ColorBox also supports LUT accuracy and can stack 1D LUTs, which is crucial in making ColorBox unique.”

Being able to stack 1D LUTs gives Astora’s team more flexibility for gamma mapping and adjusting the gain of the RGB channel. They can easily resolve the common LED shooting issue known as “homochromatic metamerism” using 1D LUTs for visual matching and correction, whether for black balance or color saturation. Lin added, “In an HDR workflow, the requirements for LUTs precision are extensive. With ColorBox, we’re able to apply the highest specification LUT (33pt), which significantly reduces issues like posterization in high-brightness and high-saturation work scenarios.”

For a recent HDR visual effects film project, “Maddog Aria”, the team developed SDR and HDR full-process monitoring, and live color grading on-set based on the director’s requirements. They unified the colors between pre-production and post-production, using the ACES standard for on-set color management for pre-production and applying color grading and VFX color management for post. On other projects, they’ve leveraged a custom integrated video assist system with AJA hardware components to use with Live Grade Studio and QTAKE. 

Astora Digital CEO Marco Wang explained, “ColorBox offers a wide range of down-conversion solutions from HDR to SDR. By integrating ColorBox into our signal processing chain, we were able to optimize our LUT box resources significantly. ColorBox’s real-time and automatic signal conversion capabilities reduced the time and cost of equipment, allowing us to focus on on-set HDR color grading. And after setting the desired HDR style, we only need to make minor adjustments to the ColorBox’s conversion parameter.”

In addition to using its video assist system for film and television production and post, Astora Digital also taps it for live broadcasting and recording, leveraging the AJA Io 4K Plus and KONA 5 with OBS for live streaming HDR video on platforms like YouTube. They also use other AJA products to record HDR content for hosting gaming programs. 

Harnessing technology from AJA, and ColorBox in particular, has allowed Astora Digital to elevate the quality of services it provides in the fast-changing world of film and television production, which in turn, elevates their clients’ work. Astora Digital Workflow Manager Edge Dong concluded, “ColorBox really stands out as the only on-set color management device available to integrate multiple powerful features with a plug-and-play user experience. It contains the trusted reliability that the AJA brand is known for while incorporating robust built-in color processing pipelines like the AJA Color Pipeline and the highly acclaimed Colorfront pipeline, along with many other powerful functionalities. We’re thrilled with the benefits it’s brought to our daily operations.”