Unmasking Samsung QN90A HDR Banding In Flat Panel Mode

Unmasking Samsung QN90A HDR Banding In Flat Panel Mode

The Samsung QN90A is celebrated for its quantum‑dotted brilliance and almost perfect black levels. Many users, however, have reported a peculiar problem when the television is set to “Flat Panel” mode – a form of HDR that can be accessed through the picture settings. The phenomenon manifests as thin horizontal lines of slightly different luminance that become apparent in scenes with subtle gradients. In this article we dissect the problem, explain why it occurs, and give you a step‑by‑step guide to mitigate or eliminate it entirely.

What Is HDR Banding and Why Does It Matter?

HDR (High Dynamic Range) imaging is all about capturing and reproducing a broader range of light and color. When a display is driven into HDR, it often has to adjust pixel brightness more aggressively than in SDR. If the pixel‑level resolution of that adjustment is insufficient, the result is banding – a visible staircase of tone levels rather than a smooth gradient.

Banding can be especially noticeable in flat‑sided surfaces where subtle differences in luminance are emphasized. It can distract from the visual experience, turning a cinematic masterpiece into a display of imperfect strips. Samsung has addressed banding in many of its models, but the QN90A’s flat panel mode is one area where a small fraction of owners still complain.

Samsung QN90A Overview

• Panel type – Mini‑LED backlit QLED
• Resolution – 4K (3840 × 2160)
• Peak brightness – 2000 cd/m² in HDR
• Contrast ratio – 200,000 : 1 (typical)
• HDR formats – HDR10, HDR10+, HLG
• Color gamut – 120 % DCI‑P3

The QN90A’s backlight is split into thousands of zones, giving it an incredible depth of black and detail. The “Flat Panel” mode is a specialized setting that removes certain local‑dimming algorithms in favour of a more even illumination across the screen – ideal for some gaming setups but also the trigger for banding issues.

Flat Panel Mode Explained

Flat Panel mode disables the variable‑dimming features that normally adjust backlight intensity behind bright objects while maintaining darkness around dark objects. By doing so it delivers a uniformly bright image that reduces motion blur and eliminates the “halo” effect around bright objects. However, the trade‑off is that the backlight can no longer respond as finely to subtle changes in brightness. When HDR content is played, the lack of local contrast can cause the pixel luminance to be mapped onto a smaller set of discrete levels. That mapping is where banding originates.

How to Spot HDR Banding on Your QN90A

1. Open a HDR‑rich source – A high‑quality Blu‑ray or streaming app that supports HDR10+ (for example, Netflix, Amazon Prime Video, or a Blu‑ray disc).
2. Switch to Flat Panel mode – Go to Picture → Expert Settings → Picture Mode → Flat Panel.
3. Watch scenes with gradual light changes – Sunrise, sunset, or a night‑time cityscape.
4. Look for subtle horizontal lines – These usually appear where the light intensity rises or falls slowly.
5. Zoom in the picture – In the on‑screen menu, use the “Zoom” feature to magnify the image. This makes banding far easier to see.

If you observe a repeating pattern of luminance changes, the display is likely suffering from banding in that mode.

Common Causes of Banding

Step‑by‑Step Troubleshooting Guide

1. Verify Signal Quality

• Use an HDMI 2.1 cable – Ensure it is certified and capable of carrying the full bandwidth.
• Check the source device – If you are using an AV‑receiver, make sure it is HDR10+ compatible.
• Confirm HDR metadata – On the source device, look for “HDR10+” or “Dolby Vision” indicator in the playback details.

If the source or cable is not optimal, banding can appear even on a perfectly working TV.

2. Update the TV Firmware

1. Connect to the internet – Through Wi‑Fi or Ethernet.
2. Go to Settings → Support → Software Update – Tap “Update Now.”
3. Wait for the update to finish – The TV will reboot automatically.

Samsung’s firmware updates often include corrections to the HDR mapping algorithm, which can reduce or eliminate banding.

3. Re‑configure HDR Settings

• Open Picture → Expert Settings → HDR.
• Switch to HDR10+ – If the source is HDR10+, selecting HDR10+ ensures that the TV uses the proper dynamic metadata.
• Turn off HDR10+ to HDR10 conversion – Some users find that disabling conversion removes artifacts.

If you prefer to keep the Flat Panel mode but still want HDR10+, try setting “HDR 10 Plus” to “Off” and see if the banding subsides.

4. Adjust the Flat Panel Parameters

The QN90A offers a “Flat Panel” sub‑menu where you can fine‑tune brightness and contrast.

• Brightness – Decrease slightly if you see bright banding.
• Contrast – Increase a bit to help the display spread the gradient more evenly.
• Dynamic Tone Mapping – Turn it on to let the TV dynamically adjust luminance levels.

These tweaks can often soften the visible stair steps.

5. Try “Normal” or “Standard” Picture Mode

Switching to a non‑flat mode eliminates banding entirely but introduces the possibility of motion blur or halos. Test both options with your content to decide which trade‑off works best for you.

Advanced Solutions for Persistent Banding

A. Re‑calibrate the Display

Samsung offers a calibration tool that can be run through the TV’s menu. This tool maps each backlight zone to the correct luminance value. Follow the on‑screen prompts and let the calibration complete.

B. Use a Dedicated HDR Processor

If you have an AV‑receiver that supports HDR10+ and local‑dimming, place it between the source and the TV. The receiver can process HDR metadata and output a cleaner signal.

C. Contact Samsung Support

If all else fails, open a support ticket. Samsung may provide a hardware repair or replacement, especially if the issue is a defect in the backlight zones.

When Is Flat Panel Mode Worth the Banding?

1. Gaming on a high refresh rate – The uniform illumination reduces motion blur, which can be critical for fast‑paced titles.
2. Professional design work – Flat lighting can reduce eye strain when working with subtle color gradients.
3. Certain streaming services – Some providers recommend flat panel mode for their specific HDR implementation.

If banding is minimal or acceptable for your use case, you might keep flat panel mode enabled and simply use the adjustments above to tame the artifacts.

Visualizing the Problem

For those who want a quick glance at what banding looks like, this image shows a side‑by‑side comparison of a scene in Flat Panel mode versus a normal mode. The bands are clearly visible in the flat panel version, whereas the normal mode delivers a smooth gradient.

Quick Reference Checklist

• Verify HDMI 2.1 and source device compatibility.
• Update firmware to the latest version.
• Set HDR10+ if available.
• Fine‑tune Flat Panel brightness and contrast.
• Enable Dynamic Tone Mapping.
• Re‑calibrate or use an HDR processor if banding persists.

Final Thoughts

The Samsung QN90A remains one of the most powerful televisions on the market, but like any sophisticated device, it has quirks. HDR banding in Flat Panel mode is one such quirk that can be addressed with a combination of software tweaks and hardware checks. By following the steps above you can either eliminate the banding entirely or bring it down to a level that is invisible to most viewers.

Remember: the goal is to deliver an immersive, distraction‑free visual experience. Whether you choose Flat Panel mode for its clarity or stick with a more dynamic mode, understanding the underlying mechanics empowers you to make the best choice for your home entertainment setup.