LCD dark-room inspection

Check backlight bleed without camera exaggeration.

Use controlled black and near-black patterns, then compare different viewing positions to separate fixed light leakage from IPS glow.

FreeAbout 2 minutesRuns locally
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How to run this test

  1. Use realistic conditions

    Dim the room, remove direct reflections, and set the panel to the brightness you normally use. Turn off dynamic local dimming only if you want to compare both states.

  2. Open the black pattern

    Enter full screen and wait a few seconds for your eyes to adapt. Look at edges and corners without staring at one bright control element.

  3. Change your position

    Move slightly left, right, closer, and farther away. Glow that changes strongly with position is more likely viewing-angle-related IPS glow.

  4. Compare real content

    A test pattern is intentionally demanding. Check a dark movie or game from your normal seat before deciding whether the variation is practically distracting.

How to interpret what you see

Fixed edge patch

A bright shape that remains in the same location as you move may be light leakage or pressure-related nonuniformity.

Angle-dependent glow

A corner glow that changes with distance and viewing angle is commonly associated with IPS viewing behavior.

Reflection or camera effect

A patch that changes with room lights or appears mainly in a brightened phone photo may not reflect what you see in normal use.

Judge severity in normal use

A perfect black field in a dark room is a stress condition. The relevant question is whether fixed bright patches distract you in ordinary dark content at your normal brightness and seat. If they do, use the same setup for repeatable photos and note the exact settings.

Important limitation

ScreenVitals provides a controlled visual aid. Results depend on your panel, brightness, viewing angle, room lighting, browser, and—when photos are used—camera exposure. It does not replace manufacturer testing or calibrated measurement equipment.

Questions about this test

Know what the pattern can—and cannot—tell you.

What is backlight bleed?

Backlight bleed is visible light leakage around the edges or corners of an LCD panel when dark content is displayed. It is different from OLED behavior because OLED pixels create their own light and do not use an LCD backlight.

How is IPS glow different from backlight bleed?

IPS glow changes noticeably with viewing position and distance and often appears as a silvery or warm glow in corners. Backlight bleed is usually more fixed in location and shape. Move your head and step farther back to compare.

Should I test at 100% brightness?

Use your normal brightness first. Maximum brightness in a completely dark room can exaggerate normal panel behavior and produce an unrealistic photo. You may compare a higher setting, but base your practical judgment on normal use.

Why does my phone photo look worse than the screen?

Phone cameras often brighten dark scenes automatically, exaggerate corner glow, and add lens vignetting. Lock exposure if possible, photograph straight on, and compare the photo with what you can actually see.

Can backlight bleed be fixed?

Do not press, twist, loosen, or open the panel. Those actions can damage it and affect warranty coverage. If the issue is distracting in normal content, document it and contact the seller or manufacturer.