Have you mastered your camera and become curious about post-processing? Do you already know the basics of Adobe Photoshop want to explore advanced techniques that can take your photography to the next level? If so, you are ready to learn how to use Luminosity Masks in Photoshop.

Luminosity Masks are something that anyone serious about their post-processing needs to know. It’s not without a reason that landscape photographers love it.

Most photographers love Adobe Lightroom but it primarily allows for global adjustments. That’s something that is, unfortunately, restricting your workflow. While it still is a tool you should use, it’s one that should be combined with the use of the more advanced Adobe Photoshop.

Photoshop has fewer restrictions that allow you to make more targeted adjustments through the use of layers and masks. This is something that will do wonders for your images.

What are Luminosity Masks?

So, what are Luminosity Masks?

Simply put, they’re tone-based selections which make it possible to make targeted adjustments to only specific areas of the image. These masks can select the brights, mid-tones or darks, without affecting other parts of the photo.

Luminosity Masks aren’t found in any menu within Photoshop. They need to be manually created. This is done by making selections based on the RGB channels but we will come back to that in a minute (I’ll also introduce you to a few third-party plugins that can automate the process for you)

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) but all three can be further refined, so you can create selections of only the brightest highlights or darkest shadows.

Now, you might be wondering what makes this so important? Why are Luminosity Masks loved by landscape photographers and why are they so useful? Let’s take a closer look.

Why should you use Luminosity Masks?

Let me start by saying that Luminosity Masks aren’t the first thing you go about learning when getting into post-processing. It requires a certain understanding of how Adobe Photoshop works and you need to understand how layers and masks work before even considering using them.

Pause here if you have no idea what layers and masks are, and read up on them before moving on. Once you understand how to use them, first then are you ready to take a closer look at this more advanced technique.

Luminosity Masks are an incredibly powerful tool that can take your post-processing to the next level but don’t misunderstand what they are; just creating the masks won’t have any visual impact on the image. You still need to make adjustments with these selections activated (such as curves, color balance or dodging and burning, etc.)

What makes these tools so powerful is that you can target extremely specific parts of a photo, and apply adjustments only to that area. Many beginning photographers don’t realize how important it is to apply targeted adjustments.

Luminosity Mask Tutorial
I used Luminosity Masks to target only the highlights in the sky when processing this.

Not all adjustments look good on the entire photo. We’re going to look a little closer at how Luminosity Masks work in a minute but let me give you this small example:

Let’s say you have a photo of a winter landscape. It’s a nice balance between the cold and warm tones and you want to keep this contrast. However, the shadows are a little too yellow and could benefit from a colder blue. This can be done through the Color Balance Adjustment Layer. But making this adjustment also introduces some blue to other parts of the image, which doesn’t look good at all. That’s where Luminosity Masks come in. Now you can create a selection, or mask, that targets only the shadows and avoids introducing the adjustment to other parts of the image.

I use Luminosity Masks for the majority of my images and I have since first learning about them about a decade ago. In fact, I often use them multiple times during a workflow. Not every adjustment needs one but there are always some that do.

How do you create Luminosity Masks?

It might sound a little confusing to begin with but the good news is that creating your first Luminosity Mask isn’t that difficult at all.

Both the Brights and Dark masks are quite straight forward but it gets a little more complicated when making the Midtones.

Let’s start by creating the Brights:

Creating the first Brights/Highlights masks

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 brights selection and is often referred to as Brights 1 or Highlights 1. Marching ants define the selected area and indicate that a mask/selection is active.

The second step is to save this selection as a new channel. This allows us to use it again or further refine the selection.

Note: Photoshop only creates marching ants around areas that are at least 50% selected. That means that there are still areas that are selected that are not defined by marching ants. Look at the new channel layer for a more accurate display 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 its thumbnail
  • Hold Shift-Alt-Ctrl/Shift-Option-Cmd and click on the thumbnail once more
  • Save the new selection and rename it to Brights 2

You can further refine the selection by holding Shift-Alt-Ctrl /Shift-Option-Cmd and clicking on the thumbnail of the new channel (Brights 2, Brights 3, etc.).

Repeat this process until you have 5-6 channels, or as many as you need for the particular image.

Creating the first Darks/Shadows masks

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:

  • Hold Ctrl/Cmd and click the RGB thumbnail in the Channel Tab
  • Click Ctrl/Cmd-Shift-I to invert the selection
  • Save the selection
  • Double Click the new channel name and rename it to “Dark 1”
  • 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 first Midtones masks

Creating the Midtone masks is slightly more complicated than creating the Brights and Shadows. We need to already have created all the Bright and Dark masks we need before making the Midtones masks.

These might be slightly trickier to make but don’t let that scare you away: they are, in my opinion, the most important masks.

Here’s how you create the first Midtones Luminosity Mask:

  • Select the entire image (Ctrl/Cmd-A)
  • Subtract Brights 1 by holding Ctrl/Cmd-alt/option and clicking on the Brights 1 thumbnail
  • Subtract Darks 1 by holding Ctrl/Cmd-alt/option and clicking on the Darks 1 thumbnail
  • Save and rename the new channel to Midtones 1

Follow these steps to further refine the selection:

  • Select the entire image (Ctrl-A)
  • Subtract Brights 2 by holding Ctrl/Cmd-alt/option and clicking on the Brights 2 thumbnail.
  • Subtract Darks 2 by holding Ctrl/Cmd-alt/option and clicking on the Darks 2 thumbnail
  • Save and rename the new channel to Midtones 2

Repeat the above (but subtracting Brights 3 and Darks 3, Brights 4 and Darks 4, etc.) until you’ve created all the selections you desire.

Download our FREE Luminosity Mask Photoshop Actions

How do you use Luminosity Masks?

Keep in mind that you haven’t actually made any changes to the image by just creating the channels as explained above.

Luminosity Masks are just selections and if you’re familiar with Layers in Photoshop, you know that a layer mask will reveal or conceal an adjustment in specific areas of the image.

Looking 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.

Remember: black conceals and white reveals. (Adjustments are hidden from all black areas of the mask)

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 use the Brights 1 mask to show you exactly how it can affect your image.

Luminosity Mask Tutorial

The image above has a slightly overexposed sky that lacks details. Photoshop’s Curves Adjustment Layer is a good tool we can use to darken the sky:

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

The problem with doing so is that the adjustment affects the entire image. In other words, we darken the entire image and it now looks like this:

Luminosity Masks in Photoshop
Adjustment without Luminosity Mask

The sky looks much better but most the landscape is now completely black. Conclusion: the original image looks better.

Now, let’s add the exact same adjustment but through the Brights 1 Luminosity Mask. Activate the mask by holding Ctrl/Cmd and clicking on the Brights 1 Channel. The arching ants indicate that the selection is active so now we try again to create a new Curves Adjustment Layer.

Use the same curve as we did before but notice that only the sky is being darkened:

Luminosity Masks in Photoshop
Curves adjustment with a Brights Luminosity Mask

The shadows and Midtones have remained completely untouched but the sky looks a lot better. Brights 1 is sometimes too broad of a selection that darkens parts of the landscape too. In those cases, you use a Brights 2 or Brights 3 mask to alter only the brighter brights.

I already like image the image more but the darker shadows are too dark and lack much detail. Yet again, a perfect scenario for Luminosity Masks.

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 too broad and will affect parts of the image I feel look ok. After activating the mask and using another Curves Adjustment Layer to brighten the shadows, the image now looks like this:

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

The situations are just a few examples of when Luminosity Masks are beneficial. It would’ve been hard to get acceptable results if I hadn’t used them for those adjustments.

Certain adjustments need to be targeted to only specific areas of an image.

More situations to use Luminosity Masks

The Curves Layer Adjustment we used above is only one example of when you can use Luminosity Masks to process your images.

In fact, Luminosity Masks can be added to any adjustment you make in Photoshop.

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

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

Blending multiple images using Luminosity Masks

Luminosity Masks are also commonly used to blend multiple images. We’ve discussed that more in-depth in this article but it’s worth mentioning here too 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.

Photoshop is a go-to tool for blending images and it’s quite easy to do with layer masks (remember: black conceals and white reveals).

The challenge, however, is that when manually creating a mask using a black or white brush on a layer mask, 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.

Using Third-Party Plugins

Creating all the Luminosity Masks each time you process a new image is 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 easily create Luminosity Masks in Photoshop.

My favorite Photoshop Panel is Raya Pro (read the review here). This is an easy-to-use plugin which makes it easy not only to create Luminosity Masks but also to create other, such as the Orton Effect, Dodging and Burning, Color Corrections, Web Sharpening and more. I’ve been using this panel for years 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 Midtone Masks
  • Action to create all Bright, Dark or Midtone 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.

Conclusion

Luminosity Masks are essential for any serious landscape photographer to understand. If you use Photoshop to process your images, you need to understand how to use these advanced selections.

Being able to apply adjustments to specific parts of the image is a game-changer for most. I can’t repeat this enough: not every adjustment looks good on the entire image.

So, if you want to take your post-processing to the next level, implement Luminosity Masks into your workflow.


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Luminosity Mask Tutorial