NovaStar A8s Pro: thermal compensation and seam correction

The A8s Pro targets the most demanding new-build projects: broadcast sets, xR volumes for virtual production, and prestige lobbies where the picture must stay flawless through hours of continuous operation and studio temperature swings. It succeeds the A8s generation by adding, in revision V1.1.1, thermal compensation that corrects in real time the brightness and colour drift caused by LED module heating — a particularly disruptive issue on shoots where cameras capture the screen in close-up.

This tutorial is written for integrators deploying a new wall with this card: it covers the practical benefit of thermal compensation and free rotation compared with fixed 90-degree rotation, the seam brightness correction between cabinets, and pairing the A8s Pro with COEX controllers driven from the VMP platform, rather than the more familiar NovaLCT/ViPlex pairing. All the figures quoted come from the official A8s Pro Receiving Card Specifications V1.1.1 sheet.

The card supports up to 512 × 512 pixels at 60 Hz per module, with an exclusive multi-grey-scale calibration and the Image Booster technology already found on other high-end cards from the brand, paired here with functions specific to shooting and broadcast environments.

1. Which projects call for the A8s Pro

The A8s Pro is not a drop-in replacement for a everyday digital-signage wall: its price point makes sense on installations where the smallest rendering shift is visible to a camera or a demanding audience. Virtual-production xR volumes, broadcast set LED backdrops and prestige lobbies are its three main markets, because these are contexts where the screen runs for hours under a fixed camera viewpoint, making any colour drift immediately noticeable.

On a set, the screen heats unevenly depending on the proximity of studio lights and the density of lit pixels in each part of the image. Without thermal compensation, that uneven heat shows up as tint variations that creep in slightly over time in the final footage — a defect no camera colour calibration can fix, since it keeps changing during the shoot.

• xR virtual-production volumes with a camera tracking the screen in real time.
• Broadcast set LED backdrops filmed continuously for hours.
• Prestige lobbies where the screen stays under close public scrutiny.
• New-build projects controlled by a COEX controller and the VMP platform.

On an xR project, always ask for the exact firmware revision of the installed A8s Pro: thermal compensation was only added in V1.1.1, so a card stuck on an earlier revision does not benefit from it.

2. Official technical specifications

The table below reproduces the figures published in the A8s Pro Receiving Card Specifications V1.1.1 sheet, first published on 3 March 2023.

Thermal compensation and seam brightness correction do not replace a correct initial calibration of the wall: they correct drift over time, not a uniformity defect already present at commissioning.

3. What thermal compensation delivers in real conditions

Thermal compensation, added in V1.1.1, continuously corrects the rendering shift caused by LED module heating during operation. On a set lit by powerful lights close to the screen, some areas of the wall heat up faster than others: without correction, this shows up as a brightness and tint drift that builds up over the course of the shoot — invisible to the eye at any single moment, but obvious when comparing the first and last minutes of footage.

In practice, the card monitors its own circuit temperature and adjusts output coefficients to keep rendering constant, with no manual operator intervention during the shoot. This is especially useful in xR, where the screen is filmed in close-up and any colour drift complicates real-time compositing with virtual elements.

• Continuous monitoring of the card's circuit temperature.
• Automatic adjustment of output coefficients with no manual intervention.
• Clearest benefit on long shoots under intense studio lighting.
• Available only from revision V1.1.1 onward.

On an xR volume, run a 30-45 minute endurance test under real lighting conditions before the first shoot day, comparing a camera capture at the start and the end to validate how well thermal compensation performs on your exact configuration.

4. Seam brightness correction between cabinets

On a large wall made of many cabinets, a slightly darker or lighter line can appear at each seam — a defect especially visible in camera close-up on the flat backgrounds used in xR. The A8s Pro includes seam brightness correction that reduces this mismatch between adjacent cabinets, on top of the pixel-by-pixel calibration already performed at commissioning.

This correction acts on the boundary zone between two cabinets and does not replace a failing global calibration: a wall that was poorly calibrated from the start keeps rendering differences within each cabinet, which seam correction does not address.

• Reduces visible seam lines between adjacent cabinets.
• Complements pixel-by-pixel calibration, does not replace it.
• Especially useful on flat backgrounds filmed in close-up.

5. Image rotation: from fixed 90 degrees to free rotation

The A8s Pro supports fixed 90-degree image rotation, useful for portrait-mounted screens, but it also adds free rotation, letting the image be oriented at any angle rather than in 90-degree steps. This is particularly useful on xR volumes where ceiling panels or curved wall sections are not always mounted perfectly aligned with the natural orientation of the content.

Free rotation is set from the control software and applied at the card level, with no need to reprocess the source content upstream, which simplifies last-minute adjustments on a set where the physical layout is still being tweaked.

• Fixed 90-degree rotation for standard portrait mounting.
• Free rotation at any angle for non-aligned configurations.
• Applied at the card level, with no source content reprocessing.

6. Pairing the A8s Pro with COEX controllers and VMP

On the most complete new-build projects, the A8s Pro is paired with controllers from the COEX range, driven from VMP, NovaStar's management platform for broadcast and xR environments. VMP centralises control of several COEX controllers and their associated receiving cards, simplifying management of a set with several distinct LED walls (backdrop, ceiling, floor) that must stay in sync.

This pairing differs from the more familiar NovaLCT/ViPlex duo used on digital-signage screens: VMP is designed for control-room operation, with centralised monitoring of each card's hardware status, including thermal compensation as it is being applied, rather than for publishing playlists.

• COEX controllers driven from the VMP platform.
• Centralised management of several distinct LED walls on the same set.
• Hardware status monitoring of each card, including active thermal compensation.

Do not try to control an A8s Pro card paired with a COEX controller from ViPlex Express: that software is built for Taurus players, not for the COEX/VMP broadcast chain.

7. Multi-grey-scale calibration and HDR rendering

The A8s Pro's exclusive multi-grey-scale calibration complements Image Booster technology to refine dark gradients, a sensitive point in HDR where black shades must stay readable without crushing or visible noise. This calibration works alongside independent RGB gamma adjustment, which corrects a persistent colour cast on one channel without touching the other two.

In practice, this combination reduces the need for colour grading in post-production on xR shoots, since the LED wall's native rendering is already close to the final target grade.

• Multi-grey-scale calibration dedicated to dark gradients.
• Independent RGB gamma to correct an isolated colour cast.
• Reduces the need for colour grading in post-production.

For an xR volume, validate HDR rendering on a black-to-dark-grey gradient before adding virtual elements to the composite: that is the zone where a calibration flaw shows up first.

8. Installation checkpoints

Installing an A8s Pro card follows the general principle of NovaStar receiving cards: daisy-chain connection from the COEX controller, respecting the 512 × 512 pixel at 60 Hz maximum load per card, and loading the cabinet configuration file before any commissioning. The main difference is the installation environment, often a set with a tight shooting schedule that leaves little room for after-the-fact troubleshooting.

On these projects, it is recommended to validate the full chain (COEX, VMP, A8s Pro cards, thermal compensation) under real conditions well before the shoot date, rather than discovering a configuration limit on shooting day itself.

• Respect the 512 × 512 pixel at 60 Hz maximum load per card.
• Load the cabinet configuration file before any commissioning.
• Validate the COEX/VMP/A8s Pro chain under real conditions before the shoot.

9. Acceptance checklist before commissioning

Before handing over an xR volume or a broadcast backdrop fitted with A8s Pro cards, a structured acceptance pass avoids unpleasant surprises during a shoot, when a fix becomes far more costly in lost set time.

Commissioning procedure

1. Confirm the firmware revision

   Check that the installed A8s Pro cards are on revision V1.1.1 to benefit from thermal compensation.

2. Wire the COEX chain

   Connect the A8s Pro cards to the COEX controllers in a daisy chain, respecting the 512 × 512 pixel at 60 Hz load per card.

3. Load the cabinet configuration

   Send the cabinet configuration file to each card before commissioning the wall.

4. Control from VMP

   Connect the COEX controllers to the VMP platform to centralise monitoring of the set's LED walls.

5. Set image rotation

   Apply fixed 90-degree rotation or free rotation depending on the real orientation of each panel.

6. Correct cabinet seams

   Enable seam brightness correction and check the result on a flat background in camera close-up.

7. Validate under real conditions

   Run a 30-45 minute endurance test under studio lighting to confirm thermal compensation performance.

Frequently asked questions

Official documentation

• A8s Pro Receiving Card Specifications V1.1.1 (official PDF) — Specification sheet
• VMP Vision Management Platform User Manual V1.2.0 (official PDF) — User manual
• Official NovaStar downloads (VMP, NovaLCT, receiving cards) — Software

Related tutorials

• NovaStar VMP tutorial: controlling a broadcast and xR environment
• NovaStar calibration tutorial: evening out an LED wall
• NovaStar A10s Plus tutorial: replacement and calibration on an installed fleet
• NovaStar MX40 Pro tutorial: processor for demanding installations

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