OLED Uniformity & Low-Gray Banding
Self-emissive displays can exhibit vertical streaking (banding) or color temperature drift across large low-gray fields. Cycles full-screen 1% to 50% grays plus low-luminance primary colors.
Technical Scope & Limitations
Visual inspection only. Minor low-gray streaking on 5% gray is common on large WOLED sheets and may not be visible in normal content.
Browser rendering output can be influenced by OS display scaling, GPU driver color settings, and active HDR profiles.
- Examine the screen in a dark room at normal viewing distance.
- Start with 5% gray—the industry standard benchmark for panel uniformity.
- Look for vertical bands ("jailbars"), clouding, or uneven pink/cyan color cast across the left, center, and right edges.
- Compare 5% gray with 10% and 20% gray to determine if variation disappears at higher brightness.
What This Test Checks
- Luminance consistency on 5% dark gray—the global benchmark for OLED panel sheets.
- Vertical banding lines ("jailbars") running from top to bottom of the display.
- Color temperature tinting (e.g. pinkish tint on left edge, greenish tint on right edge).
- Comparative uniformity across 1%, 2%, 3%, 10%, 20%, and 50% grays.
How to Perform the Test
- Perform this test in a darkened room at your normal viewing distance.
- Start on the standard 5% gray field.
- Cycle through fields using your keyboard arrow keys or by tapping.
- Note whether visible vertical lines disappear on 10% and 20% gray fields.
What to Look For
- Subtle vertical streaks on 5% gray are normal on large OLED sheets. Noticeable dark bands that remain visible in normal film or game scenes indicate significant non-uniformity.
Common Display Problems & Diagnostic Guidance
Break-In Compensation Cycles
Brand-new OLED screens often improve in low-gray uniformity after running their automatic short pixel compensation cycle (typically triggered automatically after 4 hours of cumulative use).
Frequently Asked Questions
Will 5% gray banding ruin normal movie viewing?
Rarely. Unless the vertical banding is exceptionally severe, it is typically masked by real-world texture, film grain, and moving picture content.