PanelPeek → Backlight bleed and uniformity

Backlight bleed and uniformity

Light patches on a dark screen are one of the most common worries with a new LCD monitor. Some of what you see is normal for the panel type, and some of it is worth recording and asking about. This guide explains how to look at it in a consistent way.

Bleed and IPS glow are not the same

IPS glow: a faint glow that changes as you move your head or change your distance from the screen, usually strongest toward the corners at close range.
Backlight bleed: light that leaks around the edges and stays roughly in the same place as you move.

Both are easier to see in a dim room with a black screen at your normal brightness. Judging them at maximum brightness in a dark room tends to exaggerate what you will see in daily use.

How to run the check

Clean the screen and let the display warm up if you can.
Show the black pattern and look at the corners and edges from your normal seat, then move your head slightly left and right.
Switch to the grey steps and look for a corner or band that is clearly brighter or darker than the rest.
Repeat once at your usual brightness and once a little lower, and note the setting you used.

OLED displays

OLED screens do not have a backlight, so "backlight bleed" does not apply to them. You can still observe brightness uniformity, colour shift and any banding, but do not judge them with LCD bleed expectations.

Photos and what they prove

A phone photo can look far worse than the screen does to your eyes because the camera raises exposure to capture the dark scene. That makes photos a poor way to prove leakage. Describe what you see, at which brightness and from which distance, and keep your checklist as the record.

Record it as an observation, not a verdict

Mark the black and grey group with what you saw and a short note. PanelPeek does not measure the panel and cannot tell you whether a given amount of glow or bleed is within the specification for your model. For a warranty question, use the seller's or manufacturer's process.

Short FAQ

Is some glow normal on an IPS monitor?

Yes, some glow is typical for IPS technology and changes with your viewing position; it is not the same as light leakage.

Will it get worse over time?

There is no single rule; panel behaviour differs by model. A baseline record now helps you notice a change later.

Should I turn brightness to maximum to test?

Use the brightness you actually plan to work at. Maximum brightness makes dark-room leakage look worse than your daily experience.

References

Short background used for this guide; the checking steps are our own:

Dell: distinguishing IPS glow and light leakage — glow changes with angle and distance; leakage is relatively fixed.
EIZO Monitor Test — check uniformity and other items manually in a suitable environment.