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Hardware color calibrate your monitor without a colorimeter

By January 17, 2018Tech

So why do you need color calibration? Ever bought a monitor and the color seems a bit off? All monitor which aren’t factory calibrated will have a slight variation of color from real world colors, so white may appear as greenish or reddish, some colors may be washed out or darkened etc. If you are a photo editor who must produce color accurate results, you are recommended to get a colorimeter. They are specialised hardware which color calibrates your monitor. You can buy one from Amazon or maybe you can ask one of your local photo studio to rent it for a while. 

However if you are a gamer, and animator like me and you just wanna see the colors as they were supposed to be without the need to be 100% accurate, you can save some money and try your hand at this method instead.

Before you proceed with this, let me tell you that it still may not be 100% accurate but at least it will be better than most software solutions out there, if you wanna save a few bucks. Software solutions are limited by perception of your eye, this method isn’t.

Stuff you will need:

  1. A software which can pick color from an image’s pixel and display it’s RGB and LAB color value.
    Photoshop can do that. You can download photoshop’s trial.
  2. A good quality camera. A DSLR works best, but any camera which can shoot color accurate photos will do. Your budget smartphone camera won’t work.
  3. A lamp with white LED.
  4. A white thin paper to diffuse the LED lamp. You can read this article for a complete guide on how to diffuse light using household object.
  5. Basic knowledge of Photoshop.

Here are the steps:

  1. Let’s start by creating a diffused white light solution using a paper (or a white tshirt) and a white LED lamp. Place the lamp parallel to and beside your monitor, and point it in the same direction of your screen. 
  2. Open photoshop, create a new document with white as the background color. 
  3. Make the document full screen and zoom in so that the whole white covers the screen. 
  4. With the on screen control of your monitor, increase the brightness to the max. 
  5. Switch on your camera, go to setting, turn down your ISO to the lowest value, make sure hue/tone is set to auto (or neutral), and EV is set to 0. 
  6. Turn off all the lights in the room, if you have backlit keyboard, RGB mouse, etc cover it with something. 
  7. Point at the screen so that your lens is at the center, and now go back so that the lamp is in the frame too. (We added the lamp as a guide for the camera to not adjust to the tint of the monitor and display the color accurately. Some camera might adjust the to the light and change its own settings to make it appear white).

    I used my second monitor (not calibrated) as a reference instead of the lamp


  8. Click a few pictures (we will pick the best one out later) 
  9. Transfer these photos to your pc. 
  10. Drag and drop the best looking image to your photoshop document (you can turn off full screen now). 
  11. Pick your foreground color, from the center of the screen.

     

  12. Take a note of the values.
  13. Reverse the sign of the a and b values of the LAB color. (Like in the picture above, -1 will turn to 1, and 8 will turn to -8).
  14. Now write down the values of the RGB color values.
  15. You need to do some basic math now to get the value your of your monitor’s color correction settings. First step would be to look at the default values of the RGB setting of your monitor’s on screen control. Some companies like BenQ have their values at 100 while other like Samsung have that at 50.
  16. Use this formula for each other the red, green and blue (RGB) to get the values your monitor needs to be set at
    Color value of monitor = (color value of Photoshop/255) X default value of monitor’s color
    Something like
    R = 184/255*50
    G=187/255*50
    B=202/255*50
    for a samsung monitor displaying the values of the picture above.
  17. Enter these values on your monitor’s setting. (NOTE: While doing this, you may feel like the color on your screen isn’t what it should be. Change the values anyway. This is likely the effect of your eyes adapting to the tint of the monitor that was present before. Now go away from your monitor for a while, about 20-30minutes and don’t look at any digital screen in the meantime. When you come back, your screen will look natural)
  18. Now open your windows inbuilt calibration tool to set your gamma, brightness and contrast and you are good to go. You can open it by searching for Calibrate display color. 
    Note: click next on the page where it display sliders to correct color, without touching the sliders itself.