A simpler and more precise way to use luminosity masks

Jameel Hyder

Moderator
Staff member
Luminosity masks are a powerful tool to not just blend bracketed images but also do more precise editing of the areas of the image based on tonal range in the image. I have used various actions and panels and found them to be a bit frustrating to use. The reasons being:

Most create a set of masks which are typically named 'darks' and 'lights' at fixed tonal levels (for e.g. 8 lights and 8 darks at fixed steps of luminosity).
Then you try a few to see which best fit what you are looking for.
Then potentially tweak it to get to where you want it to be.
Finally remember to delete all the masks as they are added to channels. Not doing that makes the files huge.

Fortunately, there is a simpler and more precise way (actually more than one) to do this and you don't need any actions for this. I want to share one of them.

It uses the Selection tool. Here is a sample pair of images to be blended.

The two bracketed images

Exposed for highlights
Dark.jpg


Exposed for shadows
Light.jpg


Note this is for illustration purpose as I could have pushed shadows and still got a reasonable image in this particular case.

Load both of them in PS as layers with one exposed for shadows below and the one exposed for highlights on top. Align the layers. The layer ordering doesn't matter since the technique works regardless, except that the mask will need to be different if the layers are flipped. Create a white mask on the top layer - this will be edited to become the luminosity mask.

Layers.png


Now select the mask, and go to Select->Color Range. Why Color Range? Bear with me for a moment. It is a pretty powerful tool. At the top drop down, select highlights instead of sampled colors. Depending on what mask you want to create, you can use midtones, shadows or even specific colors. Set the Fuziness to 0 and start sliding the Range till you see the selection is what you desire. I normally turn on the quick mask option. Here the red area shows what is NOT selected and white what is selected. Once you get that range, work on the fuzziness (this works as feathering the mask). In this case I have the range at 92 and fuzziness at 43.

Layer 3.png

When you have this where you want it, you are done.

Layers 2.png


As an aside the same can be done using blendif as well.
 
Last edited:

Ben Egbert

Forum Helper
Staff member
Neat trick, I have to try it to see if I fully understand the steps, but it does look simple and powerful.
 

Jeffrey

Supporting Member
Good idea. Jameel. I've been using that 'color range' select method for a very long time. Once you have the selection made (not in a mask yet), you can then click on Quick mask and edit the mask with brushes to add or delete areas, or soften edges, or change the opacity to 50% (or whatever you want) to vary the strength of the final adjustment in any given area. Switching between 'selection' and quick mask allow you to use so many tools to fine tune your final selection.
 

JimFox

Moderator
Staff member
Hey Jameel,

I really like your idea here. Jeffrey already outlined the advantages of how you are creating the mask, and the flexibility once the mask is created. So good job! I have pretty much only used the method I linked to Alan for years now, it's ultra simple. But your method only requires a bit more work, and what I like with this is you can select the amount of Luminosity. With my simple method, it's just a built in selection from Photoshop with no adjustment other then adjusting the mask. I like how you are using the Color Range tool, it's a tool I use a lot, but not for this as you have described.

Thanks for sharing this!
 

AlanLichty

Moderator
Hey Alan, TK Tools is very popular. I have never used it as I still just use my method for Luminosity Masks in the following Article. https://focalworld.com/threads/ps-simple-luminosity-mask.12664/
I have a current copy of TK Tools (v7) but since I can accomplish the same thing using Range Masks with the edit tools in Lightroom (Gradient, Radial Filter and Brush) it doesn't get used often. I prefer making those types of adjustments using the RAW base image in LR whenever possible.
 

Jameel Hyder

Moderator
Staff member
Hey Jameel,

I really like your idea here. Jeffrey already outlined the advantages of how you are creating the mask, and the flexibility once the mask is created. So good job! I have pretty much only used the method I linked to Alan for years now, it's ultra simple. But your method only requires a bit more work, and what I like with this is you can select the amount of Luminosity. With my simple method, it's just a built in selection from Photoshop with no adjustment other then adjusting the mask. I like how you are using the Color Range tool, it's a tool I use a lot, but not for this as you have described.

Thanks for sharing this!
The Ctrl+Alt+2 method linked to your article selects the upper half of the tonal range - the bright half. You can see that by creating a gradient on a white background which has a smooth transition from black (0) to white (255). This method will select all pixels with brightness from 129-255. This may work in many cases but can't be targeted precisely.
 

Jameel Hyder

Moderator
Staff member
Good idea. Jameel. I've been using that 'color range' select method for a very long time. Once you have the selection made (not in a mask yet), you can then click on Quick mask and edit the mask with brushes to add or delete areas, or soften edges, or change the opacity to 50% (or whatever you want) to vary the strength of the final adjustment in any given area. Switching between 'selection' and quick mask allow you to use so many tools to fine tune your final selection.
Yes absolutely, the selection mask has lot more options to fine tune.
 
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