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Finding lightest and darkest areas

Color image
Figure 1.  Color Image

 

Color sampler tool
Figure 2.  Color Sampler Tool

In my digital darkroom workflow, one of the things I commonly do is find the lightest and darkest parts of the subject.  I sometimes also locate a medium toned, neutral color, if available.  I do this for a number of reasons.  If an image has a color cast, we can use this information to remove it using the Levels or Curves adjustments.  Also, while we make tonal adjustments, we can monitor these locations to see if we are losing detail.  This section covers the method I use to find the lightest, darkest and medium toned areas.  We will be using Figure 1 as the example image in this section.
 

Figure 1

Looking at Figure 1, we can see this image has whites and blacks.  However, the whitest white is the bit of sky in the upper right hand corner and the darkest black is the deep shadows above the white fronds on the right side of the image.  These two areas are not in the same light as the rest of the image.  Therefore, these two areas are not the ones I am looking for.  What we want to do is identify the lightest and darkest parts of the image that we consider part of the subject.  Not the specular highlights or deep shadows.

Another thing we will notice is this image has a strong bluish cast that we will want to remove.  We will be removing this color cast in the sections discussing Levels and Curves.  However, we first need to identify appropriate light, dark and neutral areas we wish to adjust.  In this image, when we search for the lightest areas, we will look in the area of the white fronds at the bottom of the image.  When we search for the darkest area, we have lots of options, but we want to avoid the dark shadows.  A good place to search for a medium toned, neutral color is in the bark of the nearest pine tree.

Lightest and Darkest Areas

To find the lightest and darkest parts of the subject, we will use the Color Sampler tool Color sampler tool in combination with the Threshold command.  When finding the lightest and darkest areas, it is important to remember that we need to find the lightest and darkest tones that we consider an integral part of the subject.
 

Color Sampler

To find the lightest and darkest parts of an image, follow these steps.


I chose the dark side of the pine tree in the middle of the image as the darkest area and one of the fronds as the lightest.  When creating the color sampler targets, the important point to remember is we are not trying to find the lightest and darkest part of the image.  We are finding the lightest and darkest areas of the subject that we wish to monitor.

Darkest area Figure 3A.  Using the Threshold Command to Find Darkest Area

Lighest area Figure 3B.  Using the Threshold Command to Find Lightest Area


Info panel
Figure 4.  Info Panel with Color Targets

Info panel

When creating a color sampler target Color sampler target, Photoshop places its information in the Info panel.  Looking at Figure 4, we can see at the bottom of the Info panel is #1 and #2.  This corresponds to the numbered targets we just created.  The RGB values are showing us the individual red, green and blue channel values.  If the image areas we targeted were truly neutral, the three RGB numbers would be the same.  Looking at target #1, which was placed on the white frond, we can see that the green and blue channels are the dominant channel.  This tells us this area has a cyan color cast to it since green + blue = cyan.  Target #2 is showing a definite blue cast since blue is 15 and red and green are both 0.


We have finished identifying the lightest and darkest areas.  Now we will identify a mid toned area.
 

Mid toned Area

To find a mid toned area of an image, we will use the Color Sampler Tool Color sampler tool in combination with the Curves control.  This target can be especially useful when using the gray eyedropper Gray eyedropper in the Levels or Curves control when neutralizing a color cast.  If the mid toned area will be used to help remove a color cast, it is important to find an area of the image whose color we want to be neutral after correcting.  In our image in Figure 1, pine tree bark represents a color that should be neutral.  So we will look for a mid toned area there.

Tip

Even though I call this section mid toned, if color correcting, the most important point is to locate an area whose color needs to be neutral.  Whether or not it is mid tone is not as important because as we will see in a later section, the gray eyedropper Gray eyedropper neutralizes color without remapping tone.  However, I like this area to be mid toned when possible so that I can monitor this area as I make other kinds of adjustments.

 

To find a medium toned area of an image, follow these steps.

Image with targets
Figure 5.  Light and Dark Color Sampler Targets

 

Info panel
Figure 6.  Info Panel with the Three Color Targets


We have now finished identifying and targeting the lightest, darkest and medium toned parts of the subject.  Figure 6 shows the Info panel with all three color targets.