How to Create Luminosity Masks in Photoshop

Layers and masks are two of the most powerful tools found in advanced photo editors such as Adobe Photoshop as they allow you to apply adjustments to specific areas of an image.

There are many types of masks, or selections, that you can take advantage of. Some are more precise than others.

Luminosity Masks are amongst the most popular when it comes to creating ultra-precise selections. Both professional and aspiring photographers have learned how important they can be.

However, you won’t find Luminosity Masks in the Photoshop menus. These need to be manually created. Perhaps that’s why so many have yet to realize their value.

Don’t worry, though. Creating them isn’t as difficult as you might fear. It actually doesn’t take more than a few steps.

Keep on reading and you’ll learn both the manual and the automated ways of creating Luminosity Masks in Photoshop.

Note: If this is the first time you hear about Luminosity Masks, I strongly recommend reading our comprehensive introduction before reading further. This article is mainly focusing on the step-by-step.

How to Manually Create Luminosity Mask in Photoshop

Luminosity Masks can be created both manually and automatically. The automatic methods (using actions or plug-ins) are going to save you a lot of time but I believe it’s extremely important to first learn how to create them manually. That gives you a better understanding of how it works.

So, do yourself a favor and learn the manual steps before you skip on to the easier method. When you understand what the masks are and how they’re created, you can go on to use the automated method(s).

Now, let’s get to it and look at how you can create Luminosity Masks in Photoshop:

Creating the Brights Luminosity Mask

We will start by creating the Brights mask. This selection targets all pixels that are considered more than 50% bright.

What that means is that only the brightest areas of the image are affected when creating an adjustment through the mask. The darker areas are left untouched.

To create the mask, you need to open an image in Adobe Photoshop and then follow these steps:

1. Press Ctrl (PC) / Cmd (Mac) on your keyboard and click on the RGB thumbnail in the Channels Tab. This will activate Marching Ants in several areas of your image.
2. Click the «Save selection as channel» icon; the selection is now saved as a channel and given the name Alpha 1
3. Double Click the name of  “Alpha 1” and rename it to “Brights 1” or “Highlights 1”
4. Press Ctrl (PC) / Cmd (Mac) and D on your keyboard to deselect the selection. The marching ants are now gone.

That’s it. You’ve now successfully created your first Luminosity Mask. It wasn’t that hard, right?

Creating the Darks Luminosity Mask

The Brights mask targets the 50% brightest pixels in an image so next up is the Darks. As you might have guessed, this mask targets the darkest 50%. It is created following almost the same steps as above but with one important additional step.

1. Press Ctrl (PC) / Cmd (Mac) on your keyboard and click the RGB thumbnail in the Channel Tab. This activates the same marching ants as when creating the Brights mask.
2. Press Ctrl (PC) / Cmd (Mac), Shift, and I on your keyboard to invert the selection
3. Click the «Save selection as channel» icon; the selection is now saved as a channel and given the name Alpha 1
4. Double Click the new channel’s name and rename it to “Darks 1”
5. Press Ctrl (PC) / Cmd (Mac) and D on your keyword to deselect the selection

Let’s break down what just happened:

The initial selection created by Ctrl (PC) / Cmd (Mac) and clicking on the RGB thumbnail targeted every pixel brighter than 50% white. That’s the exact opposite of the mask we want to create (targeting everything darker than 50% black) which is why we inverted the selection before saving.

Comparing the Brights 1 and Darks 1 mask you can see they are indeed opposites. In the Brights mask, all the bright areas are white or some shade of it, while in the Darks mask all the dark parts are white.

Note: remember that white reveals and black conceals. Everything white in a mask is selected and affected by an adjustment while everything black is hidden/protected from it. Areas of various shades of grey are affected at a lower opacity. Click here to learn more about Layers and Masks in Photoshop.

Creating the Midtones Luminosity Masks

Now that we’ve created masks that target both the brights and the darks, it’s time to create one that targets the pixels in-between.

This mask is slightly more complicated to make as we need to first create both the Brights 1 and Darks 1 mask. Don’t let this scare you away, though. Midtone masks are extremely useful for your post-processing.

Midtones target all pixels that weren’t selected in Brights 1 or Darks 1. This means that we need to select the entire image and subtract the brights and darks.

Here we go:

1. Create Brights 1 and Darks 1 as instructed above
2. Press Ctrl (PC) / Cmd (Mac) and A on your keyboard to select everything. Marching ants should now be visible along with the frames of the image.
3. Press Ctrl (PC) / Cmd (Mac) and Option (PC) / Alt (Mac) on your keyboard and click on the Brights 1 thumbnail. This subtracts the Brights mask from the selection.
4. Press Ctrl (PC) / Cmd (Mac) and Option (PC) / Alt (Mac) on your keyboard and click on the Darks 1 thumbnail. This subtracts the Darks mask from the selection
5. Click the «Save selection as channel» icon; the selection is now saved as a channel and given the name Alpha 1. Double click and rename to Midtones 1.

Let’s recap what just happened:

We started by selecting all the pixels. Next, we removed all pixels that are brighter than 50% white and darker than 50% black. This left us with a very narrow selection that’s known as Midtones 1. These pixels are neither dark nor bright.

Note: Midtones 1 is a very narrow selection since very few pixels are between 50% white and 50% black. As you refine the Brights and Darks masks further, the Midtone masks will start affecting a wider range of pixels too.

Refining the Masks to Create More Targeted Selections

By following the steps above you have successfully created your first Luminosity Masks. These can be activated by pressing Ctrl (PC) / Cmd (Mac) on your keyboard and clicking on the channel’s thumbnail.

Doing so reveals the marching ants around the selection. Adjustments made on this layer will only be applied to the areas within the marching ants.

However, Brights 1, Midtones 1, and Darks 1 are the broadest Luminosity Masks and target the majority of the image. This can often be too broad of a selection to work with.

That means you will need to refine the mask further. In other words, you need to create masks that target even fewer pixels.

This is where manually creating Luminosity Masks becomes time-consuming. Especially if you work with narrower masks such as Midtones 4. I still recommend that you practice it a few times before moving over to an automatic method.

How to Refine the Brights and Darks Masks

Refining the Brights and Darks masks are done in the exact same way. There’s no need to invert the selection since we already did this when creating our initial Darks mask.

All you need to do is follow these few steps:

1. Create your Brights 1 or Darks 1 mask
2. Activate the mask by pressing Ctrl (PC) / Cmd (Mac) on your keyboard and clicking on the channel’s thumbnail.
3. Press Shift, Alt and Ctrl (PC) or Shift, Option and Cmd (Mac) on your keyboard and click on the thumbnail once more.
4. Save the selection using the same step as before. Double-click and rename it Brights 2 or Darks 2 depending on which mask you refined.

That’s it. By following those few steps, you have refined the selection to target a smaller selection of bright or dark pixels.

You can repeat these steps with the new refined mask to create an even narrower selection. In other words, follow the steps above but click on the Darks 2 channel instead of Darks 1.

You can follow this step with as many of the new masks as you want, or until the selection is refined enough for what you need.

How to Refine the Midtones Mask

The first Midtones mask was created by selecting all and subtracting the Brights 1 and Darks 1 mask. This might give you an idea of what we need to do when refining this selection as well.

If you said “we need to subtract Brights 2 and Darks 2 from the image”, you are correct.

This is how:

1. Create Brights 2 and Darks 2
2. Press Ctrl (PC) / Cmd (Mac) and A on your keyboard to select everything
3. Press Ctrl and Alt (PC) or Cmd and Option (Mac) and click on the Brights 2 thumbnail to subtract it from the selection
4. Repeat but now click on the Darks 2 thumbnail instead to subtract from the selection
5. Save the selection by following the same step as before and rename the new channel to Midtones 2

You can follow the steps above using any of the other Brights and Darks masks. For example, you can create Midtones 4 by selecting the entire image and subtracting Brights 4 and Darks 4.

How to Automatically Create Luminosity Mask in Photoshop

As you might have picked up by now, manually creating Luminosity Masks can be quite time-consuming. Especially if you are working with refined masks such as Midtones 4 or Brights 6.

This is no small task when you at times will create them multiple times for each photo you’re processing.

Luckily, there are a few options that make it possible to create the masks with just one simple click. Let’s take a look:

Option #1: Create Luminosity Mask Photoshop Actions

A neat feature in Photoshop is that you can record certain steps of your post-processing and save them as an Action. This Action can then be used at any time to repeat all those steps in just one single click.

To learn more about Photoshop Actions and a more detailed step-by-step on how to create them, make sure to read our free article Efficient Processing with Photoshop Actions.

That being said, let’s take a quick look at how you can create your Luminosity Mask actions.

Note: The Actions menu is seen as a Play icon on the right icon panel. If you can’t see it, go to Windows -> Actions and it will open up.

1. Open the Actions panel and click the “+” icon (Create new Action)
2. Name the action “Brights 1” and place it in the “My Actions” folder (You can move it into a folder later)
3. Press the record button
4. Follow the steps explained previously to create the Brights 1 mask.
5. End the recording by pressing the stop button.

By following these steps you’ve created a Photoshop Action that will automatically create a Brights 1 Luminosity Mask when it’s played. Want to try it out? Pause the reading and give it a go now!

Now that you’ve created the Brights 1 Action, you can repeat and do the same for Darks 1, Midtones one and the refined masks.

Don’t feel like making your own Photoshop Actions? No worries! I’ve made them for you:

Option #2: Use a Luminosity Mask Photoshop Plug-in

As you become more advanced in Photoshop you’ll learn that there are certain tools that will help make life a lot easier. Photoshop Actions are one of them but at some point, it can become hard to keep the Actions folder organized.

That’s where Luminosity Mask Plug-ins or Panels come into the picture.

Some of these plug-ins are very basic while others can be used for a lot more than just Luminosity Masks. I’ll spare you all the details now but a panel that I recommend is Raya Pro.

I have written extensively about this plugin before and I recommend reading our article Essential Raya Pro Workflows for Landscape Photographers to get a more in-depth look at the possibilities.

Here is a quick preview of how you can create Luminosity Masks in Raya Pro with just a few simple clicks:

1. Open the InstaMask panel and click on a number between 1-6 on either the B (Brights), D (Darks), or M (Midtones) section. This creates a preview of that specific Luminosity Mask
2. If needed, use the sliders to further refine the mask outside the boundaries of the preset 1-6 calculations
3. Click Apply to add the mask to your selected layer mask or click another icon to add it to an adjustment layer (such as Curves or Levels)

I think it’s fair to say that this is a lot more efficient than creating the mask manually every time, wouldn’t you?

The nice part about creating Luminosity Masks in RayaPro is that you can easily apply the mask to a series of different adjustment layers. You have a panel full of options that can be used to create the perfect mask and the perfect adjustment.

Conclusion

Luminosity Masks are incredibly powerful selections that have the ability to completely change the way you process your images.

This might sound like an exaggeration but it’s not. You’d be surprised how many times I’ve had someone tell me how Luminosity Masks were a game-changer for them, and how their work has significantly improved since learning to use them.

As you know after reading this article, creating these masks isn’t nearly as difficult as you might have thought. It doesn’t take more than a few steps to do.

The only downside is that it’s time-consuming to create the full range of masks (i.e., Brights 1-6, Darks 1-6, and Midtones 1-6). That shouldn’t be a reason to avoid it, though. Take the time to learn how to make them, then purchase a Luminosity Mask plugin or create your own Photoshop Actions.

With the automated methods the masks are made in just seconds. There’s really no excuse to avoid using them.

What are you waiting for? It’s time to create your first Luminosity Masks!

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Learn More About Luminosity Masks

In this article, you’ve learned how to create Luminosity Masks in Photoshop but that’s barely scratching the surface of what you can achieve by using them. Knowing how to make them is just part one.

Below I have compiled a list of some of our most useful articles and resources that will teach you the must-knows of creating and using Luminosity Masks to achieve world-class imagery:

• An Introduction to Luminosity Masks
• 3 Effective Methods to Select and Apply Luminosity Masks
• Dodging & Burning Through Luminosity Masks
• How to Blend Images Using Luminosity Masks in Photoshop
• Little-Known Way to Create Luminosity Masks in Lightroom