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Color Bar & Alignment Test Pattern Generator

Three reference patterns for checking color reproduction, spotting banding, and testing sharpness or framing alignment: SMPTE-style color bars, a stepped grayscale ramp, and a focus grid with line pairs at several spacings. Point any camera at your screen showing this, or compare your own live feed alongside it — nothing here requires camera permission unless you turn that comparison on.

Notes

How to actually use each pattern

SMPTE BarsDisplay fullscreen, point a camera at the screen, and compare the captured colors against the known values — yellow should not look green-tinted, blue should not look purple, and so on.
Grayscale RampWatch the smooth gradient for visible steps or banding, and check that all 11 discrete blocks below it look genuinely distinct rather than several blending together.
Focus GridPoint a camera at it and note the finest line spacing that still reads as separate lines rather than solid gray — that is roughly your effective resolving limit at that distance.

What this is not

This is a generated on-screen pattern displayed at whatever brightness and color accuracy your own monitor happens to have — it is a useful comparative reference, not a factory-calibrated broadcast signal. The bottom reference strip on the color bars is labelled honestly rather than claiming to show true sub-black or super-white, since no ordinary display can physically show a signal outside the 0–255 range.

Reference

Standard SMPTE Bar Order & Values

BarApprox. RGBWhat to check
White235, 235, 235Should read neutral, not warm or cool tinted.
Yellow235, 235, 16Should not look green-shifted.
Cyan16, 235, 235Should not look overly blue or green.
Green16, 235, 16Should not look yellow or teal-shifted.
Magenta235, 16, 235Should not look purple or pink-shifted.
Red235, 16, 16Should not look orange-shifted.
Blue16, 16, 235Should not look purple-shifted.

Standard broadcast SMPTE bar order and approximate 75% values — your actual captured colors will vary with your monitor and camera.

Step-by-Step

How to Use These Patterns

  1. Pick a pattern — SMPTE bars for color accuracy, grayscale ramp for banding, or focus grid for resolving power.
  2. Display it fullscreen on one screen.
  3. Point your camera or webcam at the screen from a normal viewing distance.
  4. Compare what's captured against the known reference values above, or watch for banding and line separation depending on the pattern.

Common Questions

Frequently Asked Questions

How do I use color bars to check my camera?
Display the bars fullscreen on one device and point a second camera at the screen, then compare what the camera captures against the known bar colors and the grayscale steps for banding. This is a comparative check against a known reference, not an automatic pass/fail test.
Is this a real broadcast-calibrated SMPTE pattern?
The seven-bar colors and layout follow the standard SMPTE arrangement. What it cannot do is show true sub-black or super-white reference patches, since an ordinary display physically cannot show a signal below 0 or above 255 — the bottom reference strip is labelled honestly rather than presented as a calibrated broadcast signal.
What is the focus grid for?
It shows line pairs at four different spacings. Point a camera at it, and the spacing at which the lines merge into a gray blur rather than staying distinct tells you roughly where that camera's resolving power runs out.
Can I use this pattern in OBS or another streaming app?
Yes — open this page as a browser source or display it fullscreen on a second monitor, the same way you would use any other on-screen test pattern.
Why don't the colors match the reference values exactly?
Your monitor's own color accuracy, your camera's white balance, and ambient room lighting all affect what gets captured — this pattern gives you a known, consistent reference to compare against, not a guarantee that captured values will match it precisely.