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The tutorials in this section are for intermediate users of Photoshop Elements.
Once you understand what follows, you'll be an advanced user.
Up to now, when you've made a change to a photograph, the entire photograph was affected equally.
Or, if you made a selection, the change affected the area inside the selection equally.
Here's an example.
1) You select a portion of a photograph.
The pixels inside the selection have many brightness levels.
Some are shadows, some midtones, and some are highlights.
2) You use a Levels adjustment layer to change the exposure and contrast of the pixels within the selection.
You brighten the selection by 5 brightness levels.
The highlights, midtones, and shadows, all change by 5 brightness levels.
But, what if you want to change the highlights more than the shadows?
Maybe you've got a sky that's too bright.
You can use a luminosity mask to produce a graduated change in the brightness values of the pixels.
When you make a change of -5 brightness levels, the highlights change by -5, the midtones by less, and the shadows, change very little.
A pixel can have a brightness value of 0, which is black, or 255, which is white.
And, pixels can be the brightness values between 0 and 255, which are many shades of gray.
Luminosity is the same as brightness.
A luminosity mask uses the brightness values as a mask.
The color information is discarded.
Only B&W, or grayscale, remains.
By using grays, changes made to a selection are graduated according to the grays of the pixel brightness values.
There are two types of luminosity masks, highlight and shadow.
Here's a photograph with the two types of luminosity masks below.
Original
Highlights Luminosity Mask
Shadows Luminosity Mask
The names of the luminosity masks imply that either highlights or shadows are affected.
However, all pixels are affected, except black (0) and white (255).
While all pixels are affected, they're not affected equally.
| Shadows | Midtones | Highlights | |
| Shadow Luminosity Mask | Most Effect | Some Effect | Little Effect |
| Highlight Luminosity Mask | Little Effect | Some Effect | Most Effect |
Just remember that the two luminosity masks do more than what their names say they do.
How do the luminosity masks allow us to create a graduated change, rather than an equal change.
The luminosity masks are made from the brightness values of the pixels.
The brightness values vary from black (0), to many grays (1 to 254), to white (255).
Therefore, the masks we're using here have white, many grays, and black.
So:
• Where there's black on the mask, 100% of a change is concealed.
• Where there's white on the mask, 100% of a change is revealed.
• As the grays of the mask vary in brightness between 0% and 100%, so does the effect of a change vary between 0% and 100%.
Let's look at each type of luminosity mask in more detail.
You're going to use a Levels adjustment layer to adjust the exposure and contrast of, mostly, the highlights.
Do the following (a detailed tutorial is below).
1) Create a highlights luminosity mask.
2) Make a selection using the mask.
3) Use a Levels adjustment layer to adjust the exposure and contrast of the selection from the mask.
Let's say you darken the selected area by 5 brightness levels.
You make a change of -5, which becomes a range of change from 0 to -5.
The change varies.
The highlights change the most.
The midtones change less.
The shadows change even less.
Let's look at what a shadows luminosity mask does.
You're going to use a Levels adjustment layer to adjust the exposure and contrast of, mostly, shadows.
Do the following (a detailed tutorial is below).
1) Create a shadows luminosity mask.
2) Make a selection using the mask.
3) Use a Levels adjustment layer to adjust the exposure and contrast of the selection from the mask.
Let's say you lighten the selected area by 5 brightness levels.
You make a change of +5, which becomes a range of change from 0 to +5.
The shadows change the most.
The midtones change less.
The highlights change even less.
Because the affect of the luminosity masks overlap, especially in the midtones, use either one or the other.
A way to reduce how far a mask extends into the midtones will be described below.
If you do this, you could use both masks at the same time.
You could make a change to the highlights, and another change to the shadows.
When you make a selection of a luminosity mask, the marching ants display may not show the entire selection.
Many photographers don't realize this.
They make erroneous conclusions about what a luminosity mask is doing.
Just remember:
• All pixels are affected, except black (0) and white (255)
• While all pixels are affected, they're not equally affected.
• All of the above is correct even if the marching ants display doesn't show it to be the case.
The marching ants display only shows selected areas that have brightness values of 128, 50% gray, or brighter.
The areas in a selection with brightness values darker than 128 are not shown.
So, as happens in photography so often, what you see is not what you get.
At the end of the tutorial below, exercises are described to confirm the above.
Let's make a highlights luminosity mask.
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