Have you ever looked at a light curve in Photoshop or Lightroom, and instantly thought, “that is way too complicated for me!”?
The truth is, the tone curve in Lightroom is not that complicated, and with a little knowledge you will be able to use the tone curve to create beautiful images in new and unique ways. So put away your fear, and let’s get started understanding the tone curve in Lightroom.
What is the Tone Curve in Lightroom?
A tone curve is a diagonal line that represents the tonal range of an image. This line can be manipulated by dragging in certain areas to change the brightness and contrast of your image in that particular tonal area. Some tone curves allow you to place anchor points to create sharper, more pronounced curves which produce stronger contrast and a unique look in the tones of your image.
In Lightroom 4 or later, there are two types of tone curves: the region Curve and the RGB or Point Curve.
The region curve is the default curve you see when you open the Tone Curve panel and is the less powerful of the two curves. It controls the luminosity or brightness of your image. The RGB or point curve is the new curve introduced in Lightroom 4 and is the more powerful tone curve. It deals with both luminosity and color and gives you the ability to add anchor points along the curve. You switch between the two tone curves by clicking on the button in the bottom right corner of the Tone Curve panel.
The tonal range of a tone curve in Lightroom.
As mentioned before, the tone curve in Lightroom is simply a graphical representation of the tonal range of your image. It is represented as a straight, diagonal line that you can manipulate to change the tone of your image. The bottom left represents the shadows or darker tones of a picture, the middle of the tone curve represents the mid-tones of an image and the top right represents the highlights.
You manipulate a tone curve by clicking on the line in a particular region and dragging up or down. Simply put, dragging up adds brightness while dragging down will remove brightness and darken the image.
If you wanted to lift the shadows, meaning add brightness into the shadow areas of an image, you would click on the lower left corner of the curve and drag upwards. The image below demonstrates this.
As you click and drag the lower left portion of the tone curve, you add brightness to the shadows. Pretty straightforward.
The Region Tone Curve of Lightroom.
The region curve is the default curve in Lightroom and is the first curve you see as you enter the Tone Curve panel in Lightroom. In fact, it’s the only curve you have if you are using Lightroom 3. The region curve is also the least powerful of the curves in Lightroom for two reasons:
- you can not place anchor points and thus can only drag the curve minimally
- you only control luminosity, or brightness and not controlling color
Notice in the images below, as I hover my mouse over certain areas of the region curve, a word appears at the bottom of the graph.
The word that appears at the bottom of the graph coincides with a slider below. This indicates that you can adjust the region curve either by clicking and dragging on the line or by adjusting the slider.
Something else to notice is the white bubble or ‘envelope’ that appears around the cursor as I hover above the region curve. This bubble or envelope is showing the limits of how high or how low the region curve can move. The top of the bubble equals 100 on the slider, while the bottom of the bubble equals -100 on the slider.
Whether you move the slider to the positive or drag the curve up, the same thing occurs – brightness increases in that particular tonal area of the image. The opposite is true as well; move the slider down into the negative or drag the curve down to darken that particular tonal area of the picture.
Take note in the image below, of how the shadows slider adjusts as I drag the tone curve up.
The histogram behind the region tone curve.
As you look at a tone curve in Lightroom, you will notice a histogram in the background of the region curve. This histogram shows you the amount of luminance data in each area of the tone curve. On the image of the tone curve above, you’ll see that the luminance mountain is mostly to the right side of the graph.
That tells us something.
It tells us the image that belongs to this tone curve is a high-key image or an image of mostly light tones.
We know this because the luminance mountain is to the right meaning that most of the tonal data is in the highlight area of the graph. This tone curve belongs to the image below.
It is easy to see why the tonal data falls to the right side of the tone curve; there are very few dark areas or shadows in the image.
Understand that as you manipulate the left side of the tone curve, you are working with very few pixels, but as you adjust the right side of the tone curve, you are working with most of the pixels in the image. So be careful!
The details of the region tone curve in Lightroom.
Below is a detailed diagram of the region curve itself.
CURVE ADJUSTMENT TOOL: This tool when selected, allows you to click on a location in the image and drag up or down to brighten or darken those pixels. This is a great way to target a specific area in the image if you are unsure where that pixel lands on the tone curve itself.
SLIDERS TO EXPAND OR CONTRACT REGIONS: At the bottom of the graph, notice the shadows, darks, lights and highlights all have equal amounts of space on the graph. By adjusting these sliders, you give more or less space to each region thus allowing the slider to affect varying amounts of pixels. For example, if you drag the leftmost slider to the right, you are giving the shadows slider more pixels to control and the darks slider less to control.
CURVE PRESET: Here is where you can select a curve preset to apply to your image. You can not create a curve preset here; you must set up and save it, in the RGB or point tone curve. When in the point tone curve area there will be a Save feature so you can record your curve for later use on other images.
CURVE SELECTOR TYPE: In Lightroom 4 and above, there are two curve types, the region tone curve, and the RGB or point tone curve. Use this button to move between them.
Why use the region tone curve in Lightroom?
As you learn about the region tone curve, you may be thinking to yourself, ‘why would I ever use this tone curve? I can do all of these things in the Basic panel.’
You are correct. In the basic panel you can lift shadows, darken highlights, etc., and yes, you can do all of these things in the region curve panel as well. However, several important reasons would cause you to use the regions curve in the tone panel. They are:
FIRST: Any adjustment made in the region tone curve does NOT affect the sliders in the basic panel. Therefore, if you are maxed out on shadow lifting in the basic panel, you can come here and lift them even more.
Or, if you are trying to bring back detail in your highlights and you have dropped the highlights slider in the basic panel as low as it will go but still have not achieved the look you’re after, come to the tone curve and drop them even more.
SECOND: The tone curve is perfect for presets. I can create a preset that restores shadow detail or adds contrast to an image and apply it without affecting any of the settings in the basic panel.
For example, let’s say you want to boost the contrast of a picture where you have already adjusted the contrast and blacks sliders in the basic panel. Without disturbing those basic panel settings, you can simply come to the Tone Curve panel and create a simple S curve like the image below.
An S-curve is a contrast curve that boosts brightness in the highlights while darkening the shadows. Doing this, allows you to add contrast without touching any sliders in the basic panel.
Now that you understand the region tone curve in Lightroom, let’s talk about the RGB or point tone curve. This curve is the more powerful curve in Lightroom and is the curve that you will use more often than the region curve.
The RGB or Point Tone Curve in Lightroom.
The RGB or Point Tone Curve is the more powerful of the curves in Lightroom for several reasons. First, when the channel is set to RGB you have the ability to do everything you could do in the region tone curve. That is, adjust contrast and brightness across the entire image. But, you have the added benefit of placing anchor points to create more dramatic curves. Also there is no max or min envelope meaning you can get crazy with your curves.
In the images below of the RGB and point tone curves, notice how the channel selected determines what colors in the image the curve effects. If, for example you are in the red channel you can add red to the highlights by clicking and dragging up an upper portion of the curve. If click and drag down on the upper portion of the curve, you will remove red and add cyan to the highlights, those colors being opposite on the the color wheel.
When the channel is set to RGB, you effect all colors in the image, thus dragging the curve brightens or darkens the entire image.
Understanding these curves allows you to adjust the colors in specific tonal areas of images. This is powerful if you find your shadows have a magenta cast or your highlights have a green cast. You can fix all of those things easily in the point tone curve area.
These curves also help you accentuate color in specific areas. For example, when shooting images in the fall, I can add warmth to the shadows of my image by dragging up on the lower part of the red curve and dragging down on the lower part of the blue curve. That gives me an warm orangish tone to my shadows like in the image below.
Notice how his shirt stays white. If I were to add warmth by simply adjusting the white balance slider, the shirt would gain a yellow cast. By using the tone curve to add warmth specifically to the shadows, you can avoid this.
The power of anchor points on a tone curve in Lightroom.
One of the most powerful features of the RGB or point tone curve is the ability to add anchor points along curve. These anchor points give you the ability to manipulate a curve in a more specific and dramatic way. In the image below, I click on a lower portion of the curve and drag it down, thus darkening all the colors of the image.
If my goal is darken all the colors, then this is perfect and I can be finished. But what if I want to have darker shadows and brighter highlights? This can only be achieved with anchor points on a tone curve. In the image below you’ll notice the anchor point on the lower portion of the line holding the line down, in essence forcing my shadows to stay dark. As I drag the upper part of the line up, I create another anchor point that brightens the highlights of the image. Thus achieving darker shadows and brighter whites.
This curve I created by doing this is known as an S-curve and is a curve that causes contrast in an image. When you darken the dark tones and brighten the light tones you create contrast.
Why use the RGB or point tone curve in Lightroom?
As you can see, the point tone curve is a much more powerful curve than the regions tone curve. Let me help you understand the reasons why you would choose to use this curve.
FIRST: This curve allows you to add color to specific tonal areas of an image. As I demonstrated above, you can add warmth to just the shadows and not affect the whites. You could also add tones to highlights as well.
SECOND: This curves allows you to remove color casts found in many images. If you have every struggled with mixed or odd lighting, use the point tone curve will allow you to remove color casts from the entire image or from specific tonal areas of your image. This is powerful if you have ever struggled to get skin tones looking correct or dealt with shifting colors.
THIRD: This curve allows you to get creative and add a unique look to your images. Below I show you one example of how the point tone curve will allow you get creative, but there are so many other ways!
Get creative with the point tone curve in Lightroom.
A look that is very popular right now is the faded or matte look. This matte look can help your images to have a more vintage feel. You create this look by manipulating the point tone curve. Below is the image before I add the matte look. Notice the untouched tone curve.
To get the matte look you need to remove a true black point and a true white point to your image.
With the channel set to RGB, drag the anchor point at the bottom of the curve up and in, and also drag the anchor point at the top of the curve, down and and in. The bottom anchor point controls shadows and by doing this you raise the brightness of the shadows removing a true black. The top anchor point controls the highlights and by dragging that down and in, you remove a true white point in the image.
The image below shows you the curve and the image associated with that curve.
Notice the histograms between the two images. The first image, you’ll see the tonal mountains touching both the left and right side of the histogram. This let’s you know that your image has good tonal range. The histogram on the second image is much different. The point tone curve has removed much of that tonal range and compressed the histogram more to the center. The histogram is telling you that this image has not true black and not true white points. Which is exactly what we were shooting for.
Which image do you prefer? This look is not for everyone but hopefully you can see how creative you can get by using the tone curve.
Video explaining the Tone Curve in Lightroom
Take a look at this video to help you understand the tone curve in Lightroom. While you’re there make sure to subscribe to my channel.
READ THE VIDEO TRANSCRIPT HERE
The tone curve panel in Lightroom is a powerful tool that can help you as you edit your images. Although tone curves may appear to be difficult, hopefully you have learned that they are not difficult at all. By simply understanding the curves, and their uses you now have the ability to not only create much more unique images, but to fix or add complicated color shift to your images.
By understanding the tone curve panel in Lightroom, you become better at creating the beautiful images you want to create.