From basic correction to creative adjustments, you can do almost every part of the photographic post-production process with Adobe Lightroom. In this lesson, we explore a lesser-known feature in-depth: creative color adjustment curves. We'll use the Red, Green, and Blue channels for precise, expressive color. Let's dive in.
A Powerful Tool for Creating Images With Atmosphere
Lightroom's Develop module is where all visual adjustments take place. From adjusting the exposure and white balance to adding creative color, it happens here. The Develop module features a series of panels (boxes), each of which controls a different aspect of the image's appearance.
Before we really get into color, let's quickly review the Tone Curve. You'll find it above the HSL/Color panel.
You can click and drag points on the tone curve to adjust the lighting and contrast in the image—this will change your Point Curve type to Custom. Click back to Linear to reset the curve.
I've labeled the Tone Curve according to the tones in the image they control:
- Black Point: extreme bottom left, controls how dark the black pixels in the image are rendered.
- Shadows (1): between the black point and the middle, move this area of the curve to adjust how dark or light the shadows are.
- Midtones (2): the middle of the curve, use this part of the curve to shift the medium tones in the image.
- Highlights (3): between the middle and the white point, shift the this part of the curve to control the lighter tones in the image.
- White Point: extreme top right, controls how light the white pixels are rendered.
Much like the RGB channels you'll see later in this tutorial, the best way to learn these curves is experimentation. Here are a couple of examples of adjusting the midtones. Notice how the shape of the curve changes.
Lightening the Image With Curves
Shifting the curve up and to the left lightens:
Note, however, that this curve also changes the contrast in the image. In the shadow areas, below the point I added, the curve is steeper: contrast is increased. Above the point the curve is flattened and the contrast is decreased. Note too that there's now more saturation in colors in the shadows (especially the greens in this example), and a little less contrast in the highlights.
Darkening the Image With Curves
Shifting the curve down and to the right darkens:
Here we darker shadow areas, with less contrast (flatter curve), and darker highlights with more contrast (steeper curve).
If you click on the graph icon in the lower right corner, the dialog box expands to give you more control of the curve, with an enhanced graphics that show Lights and Darks along with Shadows and Highlights, letting you be very precise, but also quick, about contrast changes. This mode doesn't let you alter colour, however. Click the graph icon again to return to RGB color curve mode.
The Color Tone Curve
When we use the color channel curves we aren't necessarily (or at least not always) aiming for neutral, true-to-life photos—we want to create a feeling.
So far, you've seen the standard tone curve. It controls the rendering of shadows and highlights and is one tool to adjust exposure and contrast. The RGB channel curves, tucked away inside this panel, control color with precise adjustments.
Underneath the tone curve, you'll see a dropdown that says Channel. Click on the dropdown, and you'll see three separate color channels to adjust: Red, Green, and Blue.
Here's a helpful diagram to understand how each of the color adjustments impacts the image. For each of the three color channels, I've colored the graph to show visually what shifting the curve does for each channel.
Remember: the lower left side of the tone curve controls shadows, the upper right side controls highlights. When you switch to these color channels, you're adjusting each color for that part of the exposure. Let's see a few examples to bring this idea to life.
Red Channel Adjustments
The Red Channel controls the shift between reds and cyans. Because I'm focused on the shadows with this one, I'll grab the curve point in the lower-left corner.
As the diagram above shows, pulling the red channel to the right adds cyan. Pulling it to the left (or up) brings more red to the image. You could just as easily make these adjustments in the highlights, too.
Notice in the example above how the shadows change. With just this one tweak to the Red channel, you can totally control the color tinting in the shadows.
Green Channel Adjustments
Now, let's use the tone curve with the green channel. Again, refer back to the diagram above to see that this color channel controls. Moving this curve shifts the green and magenta tone balance.
This time, let's work with the midtones, the middle part of the curve. Again, I'll shift that point to the left in one example, and to the right in the second example.
I chose this image with heavy greens intentionally. It's easiest to see the effects of RGB channels in images that strongly feature the dominant color. As the point shifts to the left, the greens become even more prevalent, even tinting the dog's hair color. The right image shows magenta hues, as we reduce the greens.
Blue Channel Adjustments
Let's round out our experiments by trying out the blue channel. Again, change the dropdown, this time to Blue.
Let's try out the highlights, the top end of the curve. It's a blue-yellow adjustment. Refer to the diagram above to see how an adjustment affects your image.
As you can see in the image above, you can cool or warm your blue tones with this adjustment. Moving the highlight portion of the curve with the blue channel selected gives you precise controls.
Recapping Color Channels
You don't have to use the color curves on every image. Instead, open up these precise controls when you have a clear vision for your image. When your shadows need just a touch of red or the highlights would benefit from blue, open these tools.
These curves really require experimentation to learn, but once you get the hang of it they can be a fun and intuitive way to work. Spend time playing with your favorite images to get ideas for complete, colorful, creative control.
How to Make Creative Adjustments With Color Curves
So, many people are familiar with using curves for adjusting contrast and tonal value. We can also use curves to adjust colour in a very nice way by selectively adjusting to quickly emphasize or de-emphasize a set of colours. This isn't colour-correction: we're not making pictures appear neutral. Instead, we're using colour to add mood to a scene.
However, we do want start with a colour-corrected, normalized image, as above. The picture looks fine: contrast is good, we've adjusted the white balance to a neutral point, and there are no big pre-exisiting colour casts in the image. Evaluating a "not-to-anything" image lets us decide what aspects of the picture we want to bring out with colour.
Check out the video to see where we go with this image:
Colour is a powerful expressive tool when used with care. Take caution, though, colour can also overpower all the other aspects of a photograph. Controlling and adjusting the colour in your image is a delicate balance. When adding colour effects to your images you want to avoid simply washing the whole image with your colour of choice and instead apply the adjustment purposefully and selectively.
Other Tools to Adjust Color
Lightroom is such a deep app that it has multiple tools to serve similar functions. You might be wondering how the complete set of tools fits together and which one is right for the job at hand.
Here are other tools that control how colors appear in your image:
- White balance is a corrective tool to shift the white point of your image. It's commonly used for neutralizing casts and color correction.
- The HSL (hue / saturation / luminance) panel controls each of these three aspects for all colors. It lets you control each individual color specifically. I consider it the most precise set of color controls, and can be handy for refining the adjustments you make with curves even more.
- Saturation and vibrance don't adjust individual colors, but they do adjust their intensity and presence. Use them to dial up more or less of what you've already applied.
For more information on the various color control tools, check out our feature-length tutorial below:
- How to Add Color in Lightroom Classic Using Hue, Saturation, and LuminanceAndrew Childress01 Dec 2022
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