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10GEOMETRY / 1:1 SIGNAL

Sharpness & Geometry Test

Use fine grids, straight lines, circles and one-pixel structures to inspect scaling, overscan, sharpening halos and geometric distortion. Especially useful when connecting a PC to a TV.

  • 3 patterns
  • Fullscreen
  • No install

Browser-generated pattern · Not a laboratory measurement

PATTERNS / 03

Patterns in this test

Each pattern targets a different symptom. Start from the top, or jump straight to the one you need.

  1. 01

    Square grid

    Lines should be straight and evenly spaced, with square cells. Wavy or uneven lines point to scaling or geometry issues.

  2. 02

    Geometry & overscan

    All four red corner marks and the outer frame must be visible. If not, the display crops the image (overscan).

  3. 03

    One-pixel checkerboard

    At native resolution and 100% zoom this looks like flat, even gray. Moiré, shimmer or stripes mean the image is being scaled.

PROTOCOL / 01—04

How to use this test

Keyboard and touch

→ · Space · Enter · click
Next pattern
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Keep the hint panel visible
Esc
Exit fullscreen
Tap or move
Show controls on touch screens and mice
  1. 01

    Clean the screen gently and let it reach its normal operating temperature.

  2. 02

    Set browser zoom to 100% and use the brightness and picture mode you normally use.

  3. 03

    Start fullscreen mode. Each pattern shows a short hint about what to look at.

  4. 04

    Observe from your normal position first, then move closer only to inspect a detail.

OBSERVE

What to look for

  • All outer markers visible without cropping
  • Lines with consistent width and minimal halos
  • Circles that remain round and grids that remain square

INTERPRET

How to read the result

Soft or shimmering one-pixel detail often indicates scaling. Bright outlines can indicate excess sharpening. Cropped edges mean overscan: look for “Just Scan”, “Screen Fit” or “Original” in the TV’s aspect settings.

LIMITS

Limits of a browser test

Browser zoom must be 100%, and operating-system scaling may prevent a true one-CSS-pixel to one-physical-pixel mapping on high-density displays.

FAQ

Frequently asked questions

01Why is the one-pixel pattern not perfectly crisp?

Display scaling, browser zoom, device pixel ratio and chroma subsampling can all alter fine patterns.

02How do I check overscan?

Use the geometry pattern. Every outside border and corner marker should be visible at once.

NEXT / SCREENPROBE

Continue checking

11

Text clarity

Text at nine sizes, light-on-dark fringing and a chroma 4:4:4 check.

↗ 01

Black screen

Pure #000000 with no overlays, compression or glow.

↗ 02

Dead pixel test

Cycle exact solid colours to find dead and stuck subpixels.

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FEEDBACK / 01

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