Exposure & Brightness
Exposure controls how bright or dark your image appears. Correct exposure is the foundation of every good edit. Before adjusting contrast, colors, or sharpening, you should first make sure the image has balanced brightness. In this guide, you will learn how to read the histogram, properly expose images, and which modules to use.
Histogram Basics
The histogram shows the brightness distribution of your image. The left side is the shadows and dark areas. The middle is the mid-tones. And the right side is the highlights and bright areas. A balanced histogram usually spreads across the graph without heavy clipping on either side.
Understanding the Histogram
The histogram is one of the most important tools in photo editing. You can find it in the top-right corner of Darkroom.
What Is Clipping?
Clipping happens when an image loses detail in very bright or very dark areas. This happens when the left or right side of the histogram is cut off.
Original Image (Starting Point)
Step 1: Exposure
Using the exposure module, alter the exposure and black level correction sliders so the histogram is equally spread.
Histogram before
Histogram after
After image
Step 2: Filmic RGB (1)
Filmic RGB is one of Darktable’s most important modules. It helps map RAW brightness values into a more natural-looking image.
Histogram after
After image
Step 3: Filmic RGB (2)
In the last step, only the scene sliders of filmic rgb were used. In this step only the reconstruct sliders will be used.
Firstly, move the transition slider to its lowest possible value. Then, click the display highlight reconstruction mask box.
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Your photo preview should be all black. Next, toggle the indication of raw overexposure located in the menu below your photo preview. It's the fourth option from the left.
Then, alter the threshold slider so the only amount of white that appears covers the overexposed parts of the image.
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Increase the transition slider to 1.5 and toggle the display highlight construction mask.
Your photo should look something like this. With only the overexposed pixels showing in color.