What Are Luminosity Masks

Luminosity Masks are a method of making selections in your image based on the brightness values of the pixels in the image.  They are used as a tool by photographers to edit their images with incredible control. The term Luminosity Masks, although a good description, can strike fear into many. Being new to Photoshop they can appear overwhelming, putting you off using them in your workflow. In this article, we’ll remove the complication created by the term, and endeavour to have them much more easily understood. We are all striving to improve our post processing, and they are an important tool that will help us get there. Throughout the sections in this tutorial, we’ll explain them in detail, and how they can be created.


Luminosity Masks Explained

How To Create Luminosity Masks

Create Zone System Luminosity Masks

Luminosity Masks Explained

What Are Luminosity Masks Title Image

Luminosity Masks are unlike any other method of creating masks in Photoshop. While all the selection tools in Photoshop create hard line selections, they have smooth graduated transitions. As a result of smooth transitions, adjustments can be made to your images without the harsh adjustment lines, giving you complete tonal control. You also have incredible control over the tonal ranges that can be selected, virtually allowing you to make any selection in your image. With the control you have over adjustments, even hard line selections can be made, much more accurately than most other tools.

What Are Layer Masks?

Before we delve to deep, we first need to understand what a layer mask is. If you have a clear understanding of layer masks in Photoshop, you may want to skip ahead.

Layer masks in Photoshop are one of the reasons that Photoshop is such a powerful editing tool. Layer masks allow us to choose what areas of a particular layer are visible. A layer mask can be added to any type of layer in Photoshop, and are automatically created with adjustment layers. For the layers where they are not added automatically, you can simply add one by pressing the layer mask icon at the bottom of your layers palette. Layer masks work as simple as:

White Mask: When the layer mask is white, or where it is white, you will see the effects of that layer. Meaning if that layer is an image, you will see the parts of the image where it is white. If that layer is an adjustment layer, you will see the adjustments made, where the layer mask is white.

Black Mask: When the layer mask is black, or where it is black, you will not see the effects of that layer. Meaning if that layer is an image, you will not see the parts of the image where it is black. If that layer is an adjustment layer, you will not see the adjustments made, where the layer mask is black.

Shades of Grey: When the mask is painted a shade of grey, meaning not black or white, it will partially show the adjustment or image layer. The closer it is to black the less you will see, the closer it is to white the more you will see.

Example of Adjustment With Varying Layer Mask Painting
Actual Layer Mask and Colours
In the example shown above, a curves adjustment layer was used, and the image was darkened significantly. If you hover over the image, you will see how the layer mask was painted. On the left the entire effect of the darkening is seen, because the layer mask is white. In the middle, the effect is only partially seen, because it’s painted grey. On the right, none of the effect is seen, because the mask is painted black.

Making Selections in Photoshop?

In Photoshop, there are many ways of making selections. These selections allow us to have much greater control over the way we can edit our images. From fine adjsutments to image composites, the sky is the limit on how we can use selections. Each of the selection tools has their own unique strength and weakness. Skipping over the “dumb” tools such as the marquee tools, the more powerful tools at your fingertips in Photoshop are:

Quick Selection: This tool is looking for edges of contrast in your image, allowing you to make reasonably good selections of objects with strong edges.

Magic Wand: The magic wand tool takes the Quick Selection tool to another level. This tool allows you to control the sensitivity of the selection brush.

Color Range: Colour range is a great tool for making selections purely based on specific colours in the image. You also have the ability to set the tolerance, allowing broader or more specific selections.

Select & Mask: The select and mask tool is a powerful method of allowing you to clean up your selections and refine their edges.

All of the selection tools mentioned above are important to understand, as they are useful in your workflow in certain circumstances. Even though a few of them are smart tools, on many occasions you will still struggle to get the selection you desire. The other pitfall is that they don’t offer very smooth transitions, even if you choose to use the feathering options. This is where luminosity masks can be so powerful.

What are Luminosity Masks?

Luminosity masks are masks developed based on the brightness values, or luminance of the pixels in your image. Each of those pixels is converted to a grey scale value, dependent on the type of mask you have chosen. With the masks being created directly from the brightness values of the pixels in your images, the transition between tones is feathered. This feathering of the transitions, allows you to make smooth adjustments to specific tonal ranges without the downside of hard line selections. They can also be manipulated through the use of colours, adjustments and dodging and burning to refine your selections. These tools allow you to create luminosity masks to suit just about any purpose.

The most commonly used masks are in the light or dark tonal ranges. These masks allow you to create virtually any selection within the lights or dark areas of your image. From there the development of masks become much more complex. With some effort, you can create luminosity masks in the midtones and throughout all the tonal zones.

There are a few different methods to create luminosity masks. On the linked page we run through all of the methods available to make and adjust lights, darks and midtone masks with ADP Pro Luminosity Masks Panel. These methods include, Luminosity Masks with Layers, and Quick Masks (calculations), both of which have advantages & disadvantages.

We also have zone system masks built into the panel. These masks allow you to select areas in your images based on a 5, 11 & 19 zone system. The most powerful of the selection tools is our Heat Mapping. This overlays the zone system in a visual colour overlay, and allows you to make multiple zone selections at a time.

Luminosity Masks Explanation Image
Actual Luminosity Masks Overlay
Hovering over the image above reveals a Lights 1 Luminosity Mask. This is basically a black and white version of the image, except it’s the actual layer mask. You can see the smooth transitions throughout.

How Can You Use Luminosity Masks?

They are a powerful tool for making adjustments in all types of photography. If your image has luminance, which all images do, they can be used to make selections and control light. The uses for luminosity masks in in your workflow are only limited by your imagination. Some of the most common methods include:

Luminance Adjustments: Creating masks to control areas that you want lightened or darkened, through adjustment layers.

Contrast Adjustments: Creating greater separation between tones, helping those subject to stand out in the image.

Colour Adjustments: Using luminosity masks to control the areas where colour is added or enhanced, such as warming the highlights only in an image.

Dodging & Burning: Control the areas affected while dodging and burning.

Accurate Hard Line Selections: Defying the smooth transitions, you can use luminosity masks to make hard line selections for adjustments or compositing.

Digital Blending: Blending multiple exposures to create a more balanced final exposure.

These are only a few of the more popular examples for the uses of luminosity masks in your workflow. Don’t limit their use to only what you see in videos or tutorials, experiment and find new amazing ways to use these powerful tools.

Methods of Mask Creation

At ADP Pro we realise that everyone has different preferences when it comes to creating luminosity masks. We have incorporated many methods of mask creation within the panel, so you have options and can reap the benefits of all their strengths. In addition to the methods described above you can also create luminosity masks with:

Luminosity Masks with Layers: This method of 16-bit mask creation uses layers to create masks. The greatest benefit of using layers over other methods, is the ability to modify the mask through colour. See our tutorials on How To Create Luminosity Masks to see more details on how these tools are used.

Quick Masks (Calculations): Creating 16-bit masks with calculations using Quick Masks, this is a very powerful method of mask creation. The main benefit of this method over using layers is the power of dodging and burning the mask. See our tutorials on “How To Create Luminosity Masks” to see more details on how these tools are used.

Heat Mapping: This is a visual zone system selection tool, and one of the most powerful in its simplicity. This is fully described in: Create Zone System Luminosity Masks

Restricted & Expanded Zones: This is a tool available in Luminosity With Layers & Quick Masks. There are options for 5, 11, & 19 zone systems. You can also make selections directly from your image using these tools.

Subtraction Masks: You can create your own custom selections by subtracting masks from each other. A powerful method for removing unwanted tonal ranges.

Apply, Adjust, Replace: This is a powerful tool that allows you to apply a luminosity mask to an existing layer that does not have one. You can adjust a mask on a layer that already has one, or replace it all together. Working between the mask and image view you can see your adjustments in real time.