In this video from our Lightroom 4 A to Z Workshop on DVD, we will discuss the improvements Lightroom 4 has made on the histogram since Lightroom 3. The histogram in Lightroom 4 now shows you an image’s different ranges, which includes the exposure, highlights, whites, shadows, and blacks corresponding to the Basic Panel sliders. The histogram is actually quite a useful tool, yet many people do not have a firm grasp on the concept of a histogram. This article will hopefully give you a better understanding of what a histogram is and how the histogram is a useful tool within Lightroom 4.
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What is a Histogram?
A histogram can tell us a lot about an image, but only if we understand how to read the histogram! A histogram is a graph that displays the amount of blacks, shadows, exposure, highlights, and whites in an image (in addition to the color information). In other words, the histogram displays your image’s tonal range in the form of a visual graph. By looking at the histogram of an image, you can easily see potential problem areas within an image. We are constantly using the in-camera histogram to gauge and measure exposure, particularly when we are trying to maximize detail in our exposure.
To access your histogram, go to the Develop Module by hitting “D.” Although you can also see the histogram in the Library Module, the histogram has more functionality in the Develop Module. However, regardless of whether you are in the Library Module or the Develop Module, the one thing that remains the same is the image information below the histogram, which shows how the image was shot. The Histogram Panel can be found on the right side of Lightroom. To expand and close the Histogram Panel, simply hit “Ctrl + 0.” As you can see below, we are in the Develop Module, and the Histogram Panel is on the right side. You can also see the image information directly below the histogram.
As mentioned before, the ranges of the histogram from left to right display the blacks, shadows, exposure, highlights, and whites.
Unlike in Lightroom 3, Exposure now primarily controls the mid-tones within our histogram. From the Histogram, you can actually adjust the Exposure by holding down your mouse over the mid-tones and moving left to make the image darker, or moving right to make the image brighter. However, we recommend avoiding adjusting the Exposure through the Histogram Panel as it can be rather imprecise.
To the left of Exposure, you have your Shadows range. Shadows are tones between mid-tones and blacks as shown below.
To the left of Shadows, you have your Blacks range. Blacks are our deepest shadows in our image, and if we have too much Black tones, we end up with loss of detail in the shadows.
Going back to the Exposure mid-tones, to the right, you have your Highlights range, which are the upper-mid tones in your images.
Then, to the right of Highlights, you have your Whites range. Similar to Blacks, if your Whites are too high, highlight areas will be blown out losing all detail.
How is a Histogram Useful?
First, from the Histogram we can quickly identify clipped shadows and blown highlights. At the top of our Histogram, you will see 2 arrows on the left and right side. The left arrow will reveal Shadow Clipping, while the right arrow will reveal Highlight Clipping.
When you mouse over these arrows, Lightroom will show you where in your image you have clipped shadows or blown highlights.
Shadow Clipping will appear in your image as blue, as you can see in the image below. This means that there is a complete loss in detail in those shadows.
Blown highlights where there is complete loss of detail in the highlights will appear in red, as shown in the image below.
If you want to see both clipped shadows and blown highlights in your image at the same time, a quick shortcut is to simply hit “J” to turn on the Shadow/Highlight Alert. This shortcut is only available through the Develop Module. To turn off, just hit “J” again. As you can see in the image below, detail has been lost in both the shadows and the highlights.
A histogram is also useful because we can quickly tell if an image is overexposed or underexposed without actually looking at the image. If the levels in the histogram are pulled up against the left, the image is underexposed since the amount of shadows and blacks are high. If the levels in the histogram are pulled against the right, the image is overexposed. The amount of highlights and whites will be very high and may even be blown out in certain areas of the image.
Improvements in Lightroom 4
While the Histogram displays the same information as it did in Lightroom 3, Lightroom 4 has made much better use of the Histogram with the changes made in Process Version 2012. With Process 2012, we now have corresponding Basic Panel sliders that match up to each tonal range on the histogram.
When your mouse is hovered over the histogram, Lightroom 4 will highlight and display the range that will be affected in the image highlighting the slider in the Basic Panel as well. This also works the other way around. When you hover over the slider in the Basic Panel, the range in the Histogram Panel will be highlighted as shown in the example below.
With Process 2012 and the new Histogram, we have much more precise control over tonal ranges within our image.
Hopefully this article has given you a better understanding of what a histogram is and how it is a useful production and post-production tool.
We hope you enjoyed this article and video excerpt from the Lightroom 4 A to Z Workshop on DVD. Stay tuned for our next article and episode!
The Lightroom 4 A to Z Workshop on DVD is a 14 hour video workshop turning any Lightroom novice into a complete master of Lightroom 4 in no time! The Lightroom 4 A to Z Workshop can be purchased by itself, or within the Lightroom 4 Workshop Collection which also contains our award winning and industry standard Lightroom 4 Preset System, as well as the Lightroom 4 Workflow System.