Monitor calibration

Eight steps, each with its pattern, the exact state to reach, and which control to move in your monitor’s own menu.

Step 1 of 8 · Set up the room

This step adjusts nothing and pays the most. A panel that has just been switched on drifts in brightness and colour for the first twenty or thirty minutes, so calibrating cold means calibrating twice. Room light matters as much: calibrate in the dark and then work in daylight, and the brightness you set will be too low. Calibrate under the light you normally have, keep a window or a lamp from falling directly on the panel, and clean the screen first. Set it to its native resolution too — scaled, the one-pixel patterns in the later steps will lie to you.

Target: A steadily dim room, no light falling on the panel, and the monitor switched on for at least half an hour.

What to change: Nothing to adjust in this step

1 of 8

0/5 adjustments done

The ← → arrow keys move between steps, in full screen too.

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Almost every calibration page does one of two things: it shows you patterns and leaves you alone in front of them, or it explains the theory and sends you off to find patterns elsewhere. This one does both at once. Every step carries the pattern to look at, the specific state you are aiming for, and the name of the setting that produces it in your monitor’s menu.

The order matters and is not arbitrary. Brightness and contrast push on each other, gamma can only be judged once the two ends are settled, and sharpness lies to you if the screen is not at its native resolution. That is why it opens on setting up the room — the step that adjusts nothing and pays the most.

And it is worth saying up front how far this goes. By eye you can genuinely fix brightness, contrast, shadow detail, an approximate gamma and sharpness. What you cannot do is measure colour: that needs an instrument that reads the light coming off the panel. The end of this page explains that properly, and when buying one is worth it.

Manual

How to use it

1
Switch the monitor on half an hour early

A panel that has just been powered up drifts in brightness and colour for the first twenty or thirty minutes. Calibrating cold means calibrating twice.
2
Set the room the way you normally have it

Calibrate in the dark and then work in daylight and your brightness will be too low. And keep any window or lamp from falling directly on the panel.
3
Run the screen at its native resolution

Scaled, the one-pixel patterns in the gamma and sharpness steps do not tell the truth: you will see shimmer that belongs to the scaling, not to the monitor.
4
Go full screen and work through the eight steps

Each one tells you what to look at, what state to reach and which control to move. Mark it done as you finish so the page keeps count.
5
Go back when you need to

Contrast disturbs the blacks and brightness disturbs the whites. Needing two or three passes between those steps is normal, not a mistake on your part.
6
Finish on the verification

If all eleven squares separate and the gradient has no bands, you are done. If not, the last step tells you which one to repeat.

In depth

Things worth keeping in mind

How far by-eye calibration goes, and what to do next

This is the part almost no page on the subject puts up front, and it should. It is worth knowing what you are getting and what you are not before spending an afternoon on it.

If after the eight steps the colour still looks wrong to you, or what you print does not resemble what is on the screen, the problem has moved out of your reach and persisting by eye will not solve it. That is the point to measure with an instrument, or to hand it to somebody who will.

Fixable by eye: brightness, contrast, shadow and highlight detail, approximate gamma, sharpness, and an obvious colour cast.
Not fixable by eye: colour accuracy, delta-E, an ICC profile, panel uniformity, and matching two monitors to each other.
Signs you need an instrument: prints do not match; you edit for other people; two screens that disagree; brand colours.
What is used: a desktop colorimeter from around $150-200, or a calibration service. Print labs will usually supply the profile for their machine.
What does not work: downloading an ICC profile "for your model" off the internet. It describes a different unit than yours and usually leaves things worse.

Where these settings live

Every machine puts them somewhere different and the names shift between versions, so rather than an exact click path that will rot, here is where to look. The general rule: with an external monitor, nearly everything belongs in its own menu, and the operating system is the last resort.

On the monitor. The buttons sit behind or under the bezel, usually at the bottom right; recent models tend to have a single mini-joystick instead of four buttons. That gets you into the on-screen menu, which manuals call the OSD. Brightness, Contrast, Colour Temp, Sharpness and the picture presets all live there.

On Windows. Brightness and resolution are in Settings → System → Display. Windows also ships its own by-eye calibration wizard: open the Start menu and search for “Calibrate display colour” (the program is dccw). And for gamma, when the monitor does not offer it, there is your graphics control panel: NVIDIA Control Panel → Adjust desktop colour settings, AMD’s Radeon software, or the Intel Graphics Command Center.

On a Mac. Brightness and presets are in System Settings → Displays. The colour profile and calibration hang off the same panel, in the profile dropdown. Be aware that on recent macOS versions the built-in assistant does little without a reference instrument: for adjusting by eye, the display presets will take you further.

Before you start, on both systems: switch off the colour filters. On Windows that is Night light; on a Mac it is Night Shift and True Tone. Otherwise you are calibrating against a filter that turns itself on and off with the time of day.

External monitor → the buttons or joystick on the bezel, usually bottom right. Where nearly everything should be done.
Windows, brightness and resolution → Settings → System → Display.
Windows, its own wizard → search Start for “Calibrate display colour”.
Windows, gamma with no monitor menu → the NVIDIA, AMD or Intel panel.
Mac, everything → System Settings → Displays, with the colour profile from there.
Laptop with no external monitor → brightness is all you get. Contrast, gamma and sharpness are not adjustable: skip those steps.
Switch off first → Night light on Windows; Night Shift and True Tone on a Mac.

The monitor’s controls and what each one does

The monitor menu uses names that do not always describe what they do, and that is half the confusion.

Brightness: the backlight. Decides where black lands. The control that matters most.
Contrast: the amplitude of the signal. Decides where white lands, and clips if pushed.
Gamma: the curve between those ends. Where it is absent, the picture presets carry one inside.
Colour Temperature: whether white leans blue or orange. Look for 6500K or sRGB.
Sharpness: artificial edge enhancement. Almost always shipped high; neutral is usually near the middle.
Dynamic Contrast, Dynamic Black, eco modes: switch them off before calibrating. They change the image as you work and make it impossible to settle anything.

History

From colour bars to the probe

Calibration began in television, and it was instrument work rather than eyeballing. The SMPTE colour bars standardised in 1978 hid a device in the bottom left corner called PLUGE: three near-black bars, one below black, one at black and one slightly above. The engineer raised brightness until the third was visible and the first was not. That 1978 trick is exactly the brightness step on this page.

In computing the problem arrived with real colour. Apple introduced ColorSync in 1993 so that what appeared on screen resembled what came off the press, and 1993 also saw the founding of the International Color Consortium, which defined the ICC profile format still in use. The underlying idea was to admit that no two devices reproduce colour identically, and to describe each one with a profile rather than pretend they agree.

The sRGB space followed in 1996, proposed by HP and Microsoft, bringing with it a nominal gamma of 2.2 and a 6500K white point. Neither was chosen for elegance: 2.2 was roughly what the cathode-ray monitors of the day did through their own physics, and 6500K is average daylight. The standard we still calibrate to is largely a description of how a 1990s CRT behaved.

Desktop colorimeters got cheap through the 2000s and turned laboratory work into something anybody could buy. But the part this page covers still cannot be bought: nobody has yet invented a way for an instrument to reach over and turn the physical knobs on your monitor for you.

1978: SMPTE bars standardised, with PLUGE inside
1993: The ICC is founded and ColorSync ships
2.2: sRGB gamma, inherited from the tube
6500K: Reference white point: daylight

How it works

Why the order is what it is

A monitor has no single control that makes it right. It has several that affect one another, and calibrating them out of order is why so many people try, fail, and conclude their screen is simply bad.

On most monitors brightness does not touch the signal at all: it drives the backlight, meaning how much light gets through the panel. That is why it decides where black lands. Contrast does work on the signal, deciding where white lands and clipping the highlights if pushed too far. Since black and white are the two ends of the same scale, moving one shifts the other — which is why the first two steps have to be alternated.

Gamma is the curve between those ends: how the tones in between are distributed. It only makes sense to adjust once the ends are fixed, because it is a curve between two points, and moving the points changes the whole curve.

White point is a different kind of thing altogether. It is not an amount of light but a colour: whether your white leans blue or orange. This is where the eye stops working as an instrument, because it adapts. Look at a bluish screen for three minutes and your brain decides that is white. It is the same mechanism that makes a sheet of paper look white under an orange bulb and in sunlight.

By hand

Setting brightness with no tools at all

The step that pays the most can be done with a picture you already have on the machine, without this page or any other.

1

A night scene, a dim interior, anything with large shadows. Fill the screen with it, with nothing white around the edges.
2

You will lose every bit of detail in the dark areas. That is the deliberate starting point.
3

Very slowly. Stop the moment you can make out shapes inside the shadows, not when you can see them comfortably.
4

Look at the bezel around the image. If the photograph’s black is clearly greyer than the plastic, you have gone too far. Come back down until they match.

Diagnosis

If something is not working

Symptom:I adjust contrast and it wrecks my blacks

Likely cause:: Expected: the two controls act on opposite ends of the same scale, so moving one shifts the other.
What to do:: Alternate between the brightness and contrast steps until neither moves any more. Two or three passes is normal. If it never converges, reset the monitor to factory values and start again.

Symptom:I cannot see any of the dark patches however high I push brightness

Likely cause:: Either room light is falling on the screen, or a picture mode in the monitor is crushing the blacks.
What to do:: Kill or redirect any light hitting the panel. If that changes nothing, look in the menu for modes called Dynamic Black, Dynamic Contrast or an eco setting and switch them off: they are altering the image on their own.

Symptom:The fine lines shimmer or ripple in the sharpness step

Likely cause:: That is not sharpness: the screen is not running at its native resolution, and scaling is inventing pixels in between.
What to do:: Set the monitor’s native resolution in the system display settings. On a laptop driving an external monitor, check the scaling factor too — it is usually sitting at 125% or 150%.

Symptom:My monitor has no gamma setting in its menu

Likely cause:: Many consumer monitors do not expose one; instead they carry picture presets with a gamma baked into each.
What to do:: Work through the presets looking for whichever lands nearest 2.2 — the one labelled sRGB is usually the most faithful. Leave correcting from the graphics card as a last resort: that adjusts the signal rather than the panel and can introduce banding.

Symptom:The gradient in the final check has wide bands

Likely cause:: Not your calibration: it is the colour depth the chain is running at, or a correction being applied to the signal.
What to do:: Check in the graphics card settings that output is at 8 bits per channel or better and that the colour format is not in a reduced mode. If you had adjusted gamma from the operating system, put it back to default.

Symptom:I calibrate, and the next day it looks different

Likely cause:: Nearly always the room light rather than the monitor. It can also be the system applying a night filter.
What to do:: Turn off night light or reading mode while calibrating and while judging. And remember that if you calibrated at night you will need more brightness by day: that is not it drifting out of calibration.

Trivia

Things worth knowing

Your brightness control does not touch the signal

On an LCD it drives the backlight, the lamp behind the panel. That is why it moves where black sits and cannot recover detail that contrast has already clipped. On an OLED it works differently: each pixel makes its own light, and the control acts on those.

Gamma 2.2 comes from the physics of the tube

A CRT responded to voltage with a curve whose exponent sat near 2.2, because of how the electron gun worked. When LCDs arrived without that curve, they were made to imitate it rather than break every image in existence. We still calibrate to a standard describing a retired technology.

Your eye recalibrates itself, which is why it cannot judge colour

It is called chromatic adaptation. Within two or three minutes your brain decides the white of whatever you are looking at is *the* white, and from then on you cannot assess it. It is what makes paper look white under an orange bulb and in sunlight, which are entirely different light.

Factory sharpness is turned up deliberately

Nearly every monitor ships with sharpening above the neutral point, because an over-sharpened image catches the eye on a shop shelf beside twenty others. At home it shows as a bright halo stuck to every fine line and every letter.

PLUGE is still in use

Those three near-black bars in the corner of the test card remain the correct way to set brightness in a studio, forty-eight years on. The technique never improved because it never needed to: it works.

Questions

Frequently asked questions

Can you calibrate a monitor without a colorimeter?

Partly, and that part is most of what actually bothers most people: brightness, contrast, shadow detail, an approximate gamma and sharpness. All of that can be fixed by eye and the difference is immediate. What you cannot get is colour accuracy — knowing whether your white sits at 6500K or 7200K, or how far each tone strays. That requires measuring the light coming off the panel, and no eye and no browser can do it.

When do I actually need a colorimeter or a professional?

When colour has to match something that is not your screen. If you print and the paper does not resemble what you saw, if you edit photos or video that other people will view on other screens, if you work with brand colours, or if you have two monitors that must match each other. In those cases no amount of by-eye work will get you there, and continuing to try is wasted time. An entry-level colorimeter runs about $150-200 and pays for itself quickly if you are in that position; there are also calibration services, and many print labs will give you the profile for their machine.

What is an ICC profile, and why does this page not generate one?

It is a file describing how your particular screen reproduces colour, so the system can compensate for the difference. Producing one means measuring dozens or hundreds of colour patches with a probe resting on the panel and comparing what was measured against what was asked for. Without that measurement no profile is possible: any page offering you an ICC without having measured anything is handing you some other monitor’s generic profile, which is worse than having none.

Better to adjust on the monitor or in the operating system?

On the monitor wherever you can. The panel’s own controls work on the hardware and leave the signal alone; correcting from the system or the graphics card alters the values before they are sent, which reduces the number of available tones and can produce banding in gradients. Save the system for whatever the monitor does not offer.

What colour temperature should I use?

6500K, or the preset labelled sRGB, for essentially everything: it is the standard for the web, for photographs and for video. Monitors commonly ship at 9300K or in a "cool" mode because a bluish white looks brighter in a shop. Drop to 5000K only if you work comparing against printed paper under standardised lighting, which is a narrow case.

Does this work for a laptop?

The steps do, with one real limitation: laptops almost never have a monitor menu, so brightness and whatever the system offers is all you can move. Contrast, gamma and colour temperature are usually not adjustable. The brightness step still works exactly the same, though, and it is the one you notice most, while the checking steps tell you what to expect from your panel.

How often should I redo it?

Panels drift over time, particularly in their first months and on lamp-backlit displays. Every six months is reasonable for ordinary use. But the commonest reason to redo it is not drift, it is the surroundings: if you change the lighting in the room, or move the monitor, at least run the brightness step again.

How is this different from a screen test?

A screen test hunts for defects: it answers "is it broken?". This page does not hunt for defects, it walks you into changing settings: it answers "how do I make it right?". The patterns resemble each other because the physics is the same, but one ends in a verdict and the other ends with controls moved. If what you suspect is a dead pixel or burn-in, start with the screen test instead.