Luminosity Masks is a type of
selection in Photoshop . But theywon’t be found in any menu.
When you make an adjustment through a Brights Luminosity Mask, only the brighter areas of the image will be affected while the darker and midtone pixels will be left untouched.
There are a few different ways to create Luminosity Masks . One simplest method is given below :
A : Creating the Brights Luminosity Mask
- The first Luminosity Mask we’ll create is the Brights mask . It targets only the pixels that are considered more than 50% bright.
- Here , only the brighter areas of the image will be affected while the darker and midtone pixels will be left untouched.
- Open the image in photoshop
 |
| Picture -1 (Original Picture) |
2. Press
Ctrl + Click in the RGB thumbnail in the Channels Tab (
Window --> Channel).
You can see the selection of some of the areas .
 |
| Picture - 2 |
- Whatever you do with this picture , only the brighter areas of the image will be affected while the darker and midtone pixels will be left untouched.
- The initial selection created by Ctrl+ clicking on the RGB thumbnail targeted every pixel brighter than 50% white.
3. Save the selection by clicking the
Select --> Save selection as channel icon. The selection is now saved
as a channel and given the name A1.
4. Double Click the name of your new channel “A1” and you can see channel options like :
5. Press
Ctrl+ D to deselect the selection .
6. Output :
That’s it; you’ve now created your first Luminosity Mask!
B : Creating the Dark Luminosity Mask
Here , the process is almost the same as for Brights one, but you need to invert the selection:
- Open the image in photoshop
- Press Ctrl + Click in the RGB thumbnail in the Channels Tab (Window --> Channel)
(Step 1 and 2 are same as above)
3.
Ctrl + Shift + i (Or,
Select --> Inverse) to invert the selection .Then you can see that the inverse selection as,
 |
| Picture - 3 |
4. Save the selection by clicking the
Select --> Save selection as channel icon. The selection is now saved
as a channel and given the name A2.
 |
| (Notice that A1 is White Luminosity Mask and A2 is Dark Luminosity Mask) |
5. Press
Ctrl+ D to deselect the selection .
Now you’ve created a Darkst Luminosity Mask!
C : Compare A and B
- The initial selection created by Ctrl+ clicking on the RGB thumbnail targeted every pixel brighter than 50% white.
- Since we wanted exactly the opposite (everything darker than 50% black), we inverted the selection before saving.
- 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.
C : Creating the Midtone Luminosity Mask
- We need both Brights one and Dark one to make it.
- Basically, midtones are all the pixels that weren’t selected in Brights one and Dark one . To create the Midtones mask, we’ll take the entire image and just subtract out the brights and darks.
1. Select the entire Image ( Ctrl A)
2. Subtract Bright one (Ctrl+ alt + click on the ‘Bright one’ channel’s thumbnail)
3. Subtract Dark one (Ctrl+ alt + click on the ‘Dark one’ channel’s thumbnail)
4. Save selection and rename the new channel to ‘Midtones 1’.
Let’s recap what just happened: We started by selecting all the pixels, then removing pixels that are brighter than 50% white and then those darker than 50% black. That left us with the first (and narrowest) selection of the Midtones; the mask targets pixels that are neither dark nor bright.
You can activate one by Ctrl+ clicking on its thumbnail.
