Displaying colors accurately on a monitor isn’t always straightforward—colors can appear too cold, washed out, or overly saturated. If you work with photos, videos, or graphic design, color accuracy is crucial.
The good news? Even without a professional colorimeter, you can adjust your monitor to display colors more realistically. All you need is a bit of patience, some test images, and your smartphone.
What Is Monitor Calibration?
Monitor calibration is the process of adjusting your display so it shows colors as accurately as possible.
Every monitor has a slightly different color response, varying in contrast, white point, and brightness. Calibration aligns these variations with the RGB standard (red, green, blue), which is used by most computers, TVs, and mobile devices.
Professional calibration typically involves a colorimeter—a small device placed on the screen that measures the colors and shades your monitor actually produces. Based on this data, an ICC profile is created, mapping colors to adjust the display accurately.
But if you don’t have a colorimeter, you can use a simpler method: calibration without a device.
How to Calibrate Your Monitor Without a Colorimeter
Without a colorimeter, you can calibrate your monitor using online tools, your eyes, and a smartphone. While the result won’t be perfect, it can significantly improve color accuracy.
Step 1: Prepare Your Monitor
Before starting:
- Reset the monitor to factory settings
- Turn off automatic image adjustments (e.g., dynamic contrast, HDR, or “vivid” modes)
- Select a mode that allows manual RGB adjustment
Useful online tools include Eizo Monitor Test and Lagom LCD Test, which provide test images for adjusting contrast, gamma, colors, and brightness.
Step 2: Adjust the White Point
Start with a test image that features a neutral white or gray area, available in tools like Eizo Monitor Test.
Use the monitor’s R (Red), G (Green), and B (Blue) sliders to tweak each channel until the white on the screen matches the white of standard paper in the same room. Make sure the paper is illuminated by natural daylight, not the screen itself, which can give misleading results.
It’s best to adjust only two of the three RGB channels, leaving the third at its default, to avoid exaggerated color shifts. Lower the values rather than raising them above mid-level, as higher numbers can artificially boost signals and degrade image quality.
The goal is a neutral white that aligns with D65 (6500 K)—the standard reference white point used in most monitors, cameras, and printers.
Step 3: Adjust Gamma
Gamma controls how your monitor displays the transition between black and white, affecting contrast and shadow detail. Incorrect gamma can cause dark details to disappear or highlights to blow out.
Check gamma using the Lagom Gamma Test. Look at vertical bars with numbers and slightly squint your eyes—the point where the bars visually blend indicates your monitor’s approximate gamma.
Set the monitor to Gamma 2.2, the standard for most devices. If your monitor allows fine-tuning, use your graphics card’s control panel (e.g., NVIDIA Control Panel → Adjust desktop color settings) to make adjustments until dark tones have depth and bright areas are clear but not overexposed.
Step 4: Adjust Brightness Using a Smartphone
Brightness affects not just comfort, but color perception and contrast. Too dark, and details are lost; too bright, and colors are washed out.
Use a light meter app (e.g., Lux Light Meter Pro) to measure ambient light with your smartphone. This converts to nits, the standard for screen brightness. In a normally lit room, aim for around 120–140 nits. In darker rooms, reduce brightness to prevent overexposure; in brighter rooms, increase it for better visibility.
How Often Should You Calibrate?
Even a well-calibrated monitor changes over time. Colors can drift gradually with usage.
Professional colorists recommend calibrating at least once a month to maintain consistent color.
Modern displays are more stable than older models. If absolute precision isn’t critical, checking every few months or comparing colors across devices—like your phone, tablet, or TV—may be sufficient.
Summary
Monitor calibration is essential for accurate color representation, whether you’re working with photography, video, or design. Even without a colorimeter, you can improve accuracy using test images, your eyes, and a smartphone. Regular checks and minor adjustments ensure colors stay true, consistent, and visually pleasing for both professional work and everyday use.
