Lightroom is a great option for photography and image editing enthusiasts as it gives numerous options to edit pictures. Lightroom color curves is one such feature that enables the user to correct the color of skin tones. We will see how we can read the RGB skin tone numbers and determine the kind of editing required in the photo.
As we see in the picture below, the RGB numbers are given in the histogram. The area near the white arrow has readings:
- Red: 73.1%
- Green: 67.1%
- Blue: 60.5%
Analyzing the RGB color tones
- The value of green should be more than blue and red should be greater than green. This is a basic structure followed for all skin tones irrespective of the color of ethnicity.
- The color tones should have more than a difference of 2%. Skintones, where RGB values are almost the same, appear gray.
- When colors measure 94% and above, overexposure could be a concern.
- When colors measure 6%o or less, underexposure could be a concern.
In the above picture, the values of all colors are consistent and within the proper range of well-exposure with a good white balance.
The steps for correcting the skin tones using Lightroom are as follows:
For this editing, you need to have the current process version ( 2012 onwards) in the Color calibration tab in the Develop Module.
The above image looks perfect if you have not noticed the red/magenta spots all over the body. Let’s work on it.
Change to the tone curve panel and zoom in the face. We will choose a mid tone point on the model’s forehead to work on.
Change the tonal curve from RGB to red.
Select the sample tool in the top left-hand corner of the tonal curve panel. Click on the selected forehead area to get a sample color. You can now see a point in the red channel tone curve.
We can see two values in the curve above. The first figure is the original value of the image; the second is the adjusted value. We will be adjusting these values to improve the skin tone.
Repeat steps for green and blue channels, taking care of sampling from the same point as a red sample.
The values after the sampling are Red = 79.2, Green = 70.2 and Blue = 62.4
(Red – Blue)/2
So 8.4 is our adjustment value. Add this to the blue and red to get new values for the respective colors.
New red=70.2(green) +8.4=78.6
New blue=70.2(green)-8.4= 61.8
Change the value of the red channel to the new number (78.6). Hold the shift key and drag the selection point from 79.2 to 78.6. It’s not possible to get exact values, just get as close as possible. Follow the same process with the blue channel.
As we see in the image above, the tones are already more pleasing. You can follow the same process for the green channel also. It is a matter of personal preference. Small adjustments have to be taken utmost care of.
We can see the difference in the original and adjusted image. For darker skin tones, you need to reduce the value of red by only a small value to avoid an unsaturated look.
Using Lightroom curves, we can bring about a nice change in the skin tone without having to export the image to photoshop.