The ASC Is Open-Sourcing a Virtual Production Test Kit for LED Volumes

The American Society of Cinematographers is releasing StEM3-VP, a set of open reference assets built to evaluate and calibrate in-camera visual effects stages, and the material is joining the Academy Software Foundation's Digital Production Example Library.

• StEM3-VP targets LED volumes. The assets cover virtual production, in-camera visual effects, and large LED walls, the parts of a modern set that are hardest to prove out before a shoot.

• It is openly available. The project lands in DPEL, the ASWF library that hosts production-grade sample content for testing hardware and software.

• It continues a two-decade lineage. StEM3-VP follows the ASC's original StEM from 2004 and StEM2 in 2022.

The work comes from the ASC's Motion Imaging Technology Council, the same technical body behind the society's earlier evaluation films.

What StEM3-VP is built to do on an ICVFX stage

StEM3-VP is Standard Evaluation Material aimed squarely at LED-based in-camera visual effects. According to the ASC Motion Imaging Technology Council, the goal is to give productions a suite of tools to evaluate and verify LED ICVFX stages before principal photography begins.

The material is meant to aid the processing, evaluation, and calibration of the image path between the LED wall and the camera. That is the exact seam where color, moiré, and brightness problems surface on a volume, and where a bad match between wall output and camera capture can quietly cost a production time on the day.

The working group frames the assets as a way to standardize the setup and proving of LED walls for a given production, using openly available media and tools rather than proprietary test patterns that vary from vendor to vendor.

Why an open, shared reference matters for volumes

LED volumes are expensive to book and unforgiving to misconfigure. A common, openly licensed reference gives cinematographers, DITs, and stage engineers a fixed target to test against, so a stage can be characterized and signed off before the crew arrives.

Because the assets live in DPEL, they sit alongside other production-grade test content the Academy Software Foundation maintains for hardware and software development. We covered the Open Source Days program where StEM3-VP was slated to be presented, part of a schedule spanning color fidelity standards, OpenPBR, and studio-safe AI workflows.

The lineage gives working professionals a known quantity. The original StEM helped calibrate digital cinema projection in 2004. StEM2, released in 2022 under the ASWF Digital Assets License, shipped as a short film in QuickTime, DCP, IMF, and EXR formats, with SDR Rec709 and HDR Rec2020 PQ versions running from 48 to 1000 nits, specifically to stress a color pipeline. StEM3-VP extends that same evaluation approach to the LED stage.

The cinematographers and technologists behind it

StEM3-VP is led by a working group of ASC members, color scientists, technologists, and manufacturers. Named contributors include David Morin, who co-chairs the effort, alongside Michael Goi, ASC, Jay Holben, Curtis Clark, ASC, Wendy Aylsworth, Joachim Zell, Rod Bogart, Gary Mandle, and Tim Kang.

The DPEL integration was presented at the Academy Software Foundation's Open Source Days by Jim Geduldick of Spaceboy Labs and Jay Holben, an independent director and producer.

Curtis Clark, ASC, a named contributor to StEM3-VP, has long led the society's motion-imaging standards work. For readers tracking how the ASC has been widening access to its technical resources, this follows the society's push into education with ASC+, its subscription learning platform.

What this means for stages and the crews that run them

For anyone commissioning or operating an LED volume, StEM3-VP offers a neutral yardstick that does not belong to a single wall vendor or processor manufacturer. That lowers the risk of walking onto a stage that looks fine in a demo and falls apart under a specific camera and color pipeline.

The assets are openly available through DPEL, so stages can adopt them without licensing friction. As volumes spread beyond the largest studios, a shared calibration reference makes in-camera visual effects more predictable for the productions that can least afford a surprise on set.