Luminosity Mask Tutorial

Do you feel like you’ve learned how to use your camera and have become curious about post processing techniques? Have you already learned the basics of Adobe Photoshop and are ready to explore some more advanced and powerful techniques? If so, Luminosity Masks is where you should begin.

Luminosity Masks have become one of the most popular techniques/tools amongst photographers who use Adobe Photoshop and it’s not without a reason. Softwares such as Adobe Lightroom mainly allow for global adjustments, an aspect many find restricting in their workflow. Photoshop, however, has few limitations and by working with layers and masks, you’re able to make more selective and detailed adjustments to your images.

What are Luminosity Masks?

So what are Luminosity Masks? Simply put, they’re tone-based selections which make it possible to alter only specific tones of the image. These selections target only the brights, mid-tones or darks, letting you make the adjustments you feel are needed in only these areas.

Luminosity Mask Tutorial
Images such as this with a big dynamic range can benefit from Luminosity Masks

There are three types of Luminosity Masks: Brights (Highlights), Midtones and Darks (Shadows). However, all three can be further refined so you can create selections of only the brightest highlights or darkest shadows.

Luminosity Masks aren’t found in any lists or menus within Photoshop and need to be manually created by making selections based on the RGB channels (there are some third-party plugins that do this for you – we’ll come back to that further down).

Why/When Should You Use Them?

Luminosity Masks are considered to be an advanced technique that requires a certain understanding of how Adobe Photoshop works. Before you even consider starting to use them, you need to understand at least how masks and layers work. Once you do, you’re ready to start looking at this more advanced technique.

That being said, Luminosity Masks are an incredibly powerful tool that can take your post processing to the next level. Don’t misunderstand what they are, though. Just creating the masks won’t have any visual impact on the image – you’ll still need to make adjustments with these selections activated (such as curves, color balance or dodging and burning etc.)

In one way or another, I use Luminosity Masks for the majority of my images (often multiple times). They aren’t always necessary but once you wish to make specific adjustments, they will be extremely beneficial.

Luminosity Mask Tutorial
I used Luminosity Masks to affect only the highlights on the peaks in this image.

It’s ok to just use a soft brush directly on the layer mask in certain cases but be aware that this will cause a certain degree of haloing around the area you’re adjusting.

How Do You Create Luminosity Masks?

Though it sounds slightly confusing to begin with, you’ll quickly realize just how simple it actually is to create your first Luminosity Mask. Creating both the Brights/Highlights and the Darks/Shadows selections are fairly straight forward but it gets a little more complicated when you want to create the mid-tones. Let’s start by creating the Brights:

Creating the Bright/Highlight Selections

There are a few different ways to create these selections but I’ll stick to the easiest and most common version. Once you’ve opened an image in Photoshop, simply follow these steps:

  • Ctrl/Cmd+Click the RGB thumbnail in the Channel Tab
  • Save the selection
  • Double Click the new channel “Alpha 1” and rename it to “Brights” or “Highlights”
  • Ctrl/Cmd + D to deselect the selection

Luminosity Mask Tutorial

That’s it. You’ve now created your first Luminosity Mask! Let’s break down what just happened:

Luminosity Masks are selections based on the brightness of the image. When selecting the RGB channel we activate a selection that highlights the brights of the image. This selection is the broadest highlight selection and is often referred to as Brights 1 or Lights 1. As you can see when we created the selection, marching ants define the selected area.

With the marching ants active, you’ll need to save this selection as a channel in order to use it again later and further refine the selection. We rename it to Brights and deactivate the selection by clicking Ctrl/Cmd+D.

Note: Photoshop only creates marching ants around areas that are at least 50% selected. That means that there are still areas that are selected which are not defined by marching ants. Pay attention to the new channel layer for a more accurate definition of which parts of the image will be affected (white reveal and black conceal).

Refining the Selection

The selection we made in the steps above is the broadest bright mask that defines all the bright values of the image. When working with Luminosity Masks we often want to further refine the selection and work with even more specific parts of the image.

To further refine the Brights selection you need to:

  • Activate the Brights mask/channel by ctrl/cmd+click on the thumbnail
  • With the marching ants active, Shift-Alt-Ctrl+click/Shift-Option-Cmd+click on the same thumbnail
  • Save the new selection and rename it to Brights 2

You can further refine the selection by using Shift-Alt-Ctrl+click/Shift-Option-Cmd+click on each new selection (Brights 2, Brights 3 etc.), just make sure that the marching ants are active. Repeat this process until you have 5-6 channels or as many as you need for the particular image.

Creating the Dark/Shadow Selections

Now that you’ve created the Bright masks it’s time to move on and create the Dark/Shadow masks. These masks are created almost in the exact same way as the brights but you have to invert the first selection.

  • Ctrl/Cmd+Click the RGB thumbnail in the Channel Tab
  • Ctrl/Cmd-Shift-I to inverse the selection
  • Save the selection
  • Double Click the new channel and rename it to “Darks”
  • Ctrl/Cmd + D to deselect the selection

You can further refine the selection by following the same steps as we did when refining the Brights selections. You don’t need to inverse each selection as we have already targeted the darks/shadows by inverting the first.

Creating the Mid-tones Selections

Creating the Mid-tone masks are slightly more complicated than creating the Brights and Darks. To create a mid-tone mask we need to have already created all the Bright and Dark masks we need.

Personally, I find the mid-tone masks to be very useful so don’t be demotivated to create them just because they are a little more tricky.

To create the mid-tones we need to first select the entire image (ctrl-A) and manually subtract one bright- and one dark mask. You can subtract the mask by Ctrl/Cmd-alt/option+click on the channel’s thumbnail.

This means that to create the first mid-tone selection you need to:

  • Select entire image (ctrl-A)
  • Subtract Brights by Ctrl/Cmd-alt/option+click on the channel’s thumbnail.
  • Subtract Darks by Ctrl/Cmd-alt/option+click on the channel’s thumbnail.
  • Save and rename the new channel to Mid-tones

If you want to further refine the selection you need to:

  • Select entire image (Ctrl-A)
  • Subtract Brights 2 by Ctrl/Cmd-alt/option+click on the channel’s thumbnail.
  • Subtract Darks 2 by Ctrl/Cmd-alt/option+click on the channel’s thumbnail.
  • Save and rename the new channel to Mid-tones 2

Continue the steps above until you’ve created all the selections you desire.

(You can find a free download of our Luminosity Mask Actions for Photoshop at the end of this article)

How Do You Use Luminosity Masks?

Keep in mind that by just creating the channels/masks above, you haven’t actually made any change to the image. These are just selections and if you’re familiar with Layers in Photoshop (which is beneficial if you wish to use Luminosity Masks), you know that a layer mask will reveal or conceal an adjustment in specific areas of the image. Remember, black conceals and white reveals. If you look at the channel mask from any of the Luminosity Masks we’ve created above, you can see exactly which parts of the image will be affected when you apply that mask to an adjustment layer.

There are several ways you can activate and use a Luminosity Mask but let’s keep this as easy as possible and look only at the most basic method. In this example, I’ll only use the Brights mask to show you exactly how using the mask can affect your image.

Luminosity Mask Tutorial

The image above is an unedited file and straight out of the camera I notice that the sky is slightly overexposed and lacks details. An easy way to fix this in Photoshop is to use a Curves Adjustment Layer to darken the sky:

Curves Adjustment Layer Photoshop
By adding this adjustment I darken the entire image

The problem when using an adjustment such as the one above is that it affects the entire image. In other words, also the dark parts of the image are darkened and it now looks like this:

Luminosity Masks in Photoshop
Adjustment without Luminosity Mask

As you can see, the sky looks much better but the foreground is completely black. Despite a slightly overexposed sky, the original image was better. Now, let’s add the exact same adjustment but with the Brights Luminosity Mask selected. Ctrl/Cmd+click the Brights Channel to activate the selection and create a new Curves Adjustment Layer. By making the exact same curve the image now looks like this:

Luminosity Masks in Photoshop
Curves adjustment with a Brights Luminosity Mask

By using the Brights Luminosity Mask we have now only affected the bright tones of the image and the shadows remain untouched. Had we wanted an even more narrow selection we could have used Brights 2 or 3 to alter only the brighter brights.

The image is starting to look better but the darker shadows are too dark for my preference. Let’s look at the different dark masks and find one that only affects the darker shadows:

Luminosity Mask Darks
The Dark Luminosity Masks

By looking at the options above, I find Darks 5 to be the best option for the adjustment I wish to make. The other masks are broader than what I wish and will also alter the areas that are less dark than the darkest shadows. By selecting the mask and creating and brightening a Curves Adjustment Layer, the image now looks like this:

Luminosity Mask Tutorial
I used a Darks 5 curve to only brighten the darkest shadows

Luminosity Masks are great tools to make only targeted adjustments to the image. Had I not used masks for the two adjustments above, it would have been hard to get a result that looks acceptable. Certain adjustments need to target only specific areas of an image.

Keep Experimenting

The Curves adjustment above is only one example of when you can use Luminosity Masks to process your images. Curves & Layer adjustments are good alternatives when you wish to brighten, darken or add contrast. However, there are several other examples of when these masks can be beneficial. In fact, masks can be added to any adjustment you make in Photoshop, which means that Luminosity Masks can be used as well.

Here are some popular adjustments you can use with a Luminosity Maks:

  • Curves
  • Levels
  • Color Balance
  • Hue/Saturation
  • Photo Filter
  • … and more

Blending multiple images

Luminosity Masks are also commonly used to blend multiple images. This will be discussed more in-depth in a later tutorial but it’s worth mentioning now as it’s a popular use of these selections.

Taking multiple exposures to capture the entire dynamic range of a scene is an effective way to overcome the camera’s limitations. Cameras struggle to capture both the brightest highlights and darkest shadows in one single image which means that you’re often left with an image that has either an overexposed sky or underexposed foreground.

When importing the multiple exposures into Photoshop, you’re able to blend them together by using Layer Masks (remember: black conceals and white reveals). The challenge, however, is that when creating these masks by manually using a brush, you’re left with unwanted haloing and very revealing edges (i.e. there are darkened edges due to the darker exposure “bleeding” onto the brighter exposure). Luminosity Masks are extremely useful in situations like this. As you know by now, the masks target only specific values of the image so you’re able to blend the darker exposure into only the areas which are overexposed.

This is a more advanced use of Luminosity Masks than what we’ve covered so far and to avoid confusion I won’t be going into more detail about this now. If you wish to learn more about blending multiple exposures by using Luminosity Masks, I recommend this video by Jimmy McIntyre:

Using Third-Party Plugins

Creating all the Luminosity Masks each time you wish to process a new image will be rather time-consuming. Even when you know exactly how to make it, it takes time to make them all. Luckily, there are several plugins and panels that you can use to create Luminosity Masks with.

My favorite Photoshop Panel is Raya Pro (read the review here). This is a comprehensive panel which makes it easy not only to create Luminosity Masks but to create several other effects as well, such as the Orton Effect, Dodging and Burning, Color Corrections, Web Sharpening and more. I’ve been using this panel for a few years now and it definitely makes life easier.

Tony Kuyper’s TK Action Panel is another popular panel for Photoshop. Similar to Raya Pro, it also includes several other adjustments and options that you might find beneficial in your workflow.

Download Our Free Luminosity Mask Actions

Another way to easily create the Luminosity Masks for each image is by using Photoshop Actions.

By signing up for our newsletter, you’ll receive a free download of our Luminosity Mask Actions for Photoshop so you don’t have to do this yourself or spend money on an advanced panel. The download includes:

  • Instructions on how to install the actions
  • Individual action for 6x Bright, Dark and Mid-Tone Masks
  • Action to create all Bright, Dark or Mid-Tone Masks
  • Create all masks action
  • Action to delete all masks

Download our FREE Luminosity Mask Photoshop Actions

Before relying 100% on actions or plugins, put some effort into learning how these masks work. By doing so, it will be easier to use them later and you’ll better understand in what scenarios you should use the different masks.

Photographer's Guide to Luminosity MasksA Photographer’s Guide to Luminosity Masks is your go-to eBook for an in-depth introduction to basic and advanced masks in Photoshop. Whether you’re just getting started with Photoshop or have used it for years, this eBook is a natural place to begin expanding your knowledge. The information shared throughout A Photographer’s Guide to Luminosity Masks will teach you everything you need to know in order to take advantage of layers and masks in Photoshop.

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Luminosity Mask Tutorial