Light EQ

The Light EQ™ filter adjusts areas in an image that are too dark or too light, without affecting other areas of the photo. An effective benefit of the Light EQ™ filter is the ability to simultaneously lighten dark areas that are too dark, and darken areas that are too bright. Examples would be a photo of a person silhouetted against a bright background like the sea, or a window. In fact, most photos taken on a dull day, or with a flash, can be improved in various ways with fine adjustments.

Customized settings can be saved as a preset for future use. Presets can be selected from the Presets drop-down, or saved by clicking the adjacent Save icon.

The Light EQ™ filter features four tabs — each tab is associated with an adjustment technique that achieves results in different ways. In addition, there are several keyboard and mouse shortcuts for making adjustments on specific areas of the photo itself.

 

The four Light EQ™ tabs include:

  • 1-Step tab: For an instant, effortless exposure adjustment.
  • Basic tab: Is for very quick and easy adjustments using three sliders. Gemstone analyzes the photo and varies the adjustment throughout the image automatically. For example, darker images are brightened more. By clicking the Auto button, Gemstone fully analyzes the photo and sets the slider positions automatically. It is also possible to directly click an area of the image to generate automatic settings optimal for that area, (usually the subject of the photo).
  • Standard tab: Works like a sound equalizer but with light. Adjust the brightness and contrast of different tone bands (areas of relative brightness or darkness) of the image independently using a slider for each tone band. A graph shows the amount of brightening or darkening applied throughout the tonal range. The gray areas in the graph are suggested boundaries for adjustment to avoid clipping and loss of detail, and turn red to indicate where the sliders have been adjusted far enough to cause clipping.
  • Advanced tab: Provides ultimate control of the brightness and contrast in an image. Basic adjustment curves can be constructed using four sliders, and the curves can be manually adjusted by clicking and dragging within the graph area or on the image itself.

To open the Light EQ™ filter:

Select Filter | Exposure / Lighting | Light EQ™ from the main menu, or press Q.

The 1-Step Tab

When opening an image in the Light EQ™ filter, the 1-Step tab is set by default and automatically adjusts the image's exposure. Further adjusts can be made using the Amount slider.

The Basic Tab

To darken areas that are too bright:

  1. Drag the Shadows slider to the right to lighten and return detail to areas that are too dark.
  2. Adjust the settings using any of the controls in the table below.

To adjust midtones that are too light or dark:

  1. Drag the Midtones slider to the right to lighten and return detail to areas that are too dark.
  2. Adjust the settings using any of the controls in the table below.

To add light to dark areas:

  1. Drag the Highlights slider to the right to add light to the dark parts of the photo.
  2. Adjust the settings using any of the controls in the table below.

Light EQ™ Controls

Right-click on a slider

Right-click on a slider to reset it.

Auto

Click to allow the software to analyze the photo and apply optimal settings based on the amount of light and dark pixels in the photo. Darker photos are brightened more than photos that are already bright.

OK

Click to apply any changes and close the tool.

Cancel

Click to discard all changes and close the tool.

The Standard Tab

The Standard tab has two sets of sliders. The top set is for brightening. The lower set is for darkening. The dark-to-light gradient on each slider indicates which tone band will brighten when the slider is moved up (top row of sliders) or tone band will darken when the slider is moved down (bottom row).

Between the two sets of sliders are two horizontal bars graded from black to white. These bars indicate that sliders on the far left affect the dark tonal bands. The sliders on the right affect light tonal bands. Moving a slider changes the light in that particular tonal band.

In the middle of the bands are two graphs that change as the sliders are adjusted to represent the amount of darkening and lightening throughout the tonal range of the image. The two gray graphs show the maximum amount of brightening or darkening that can be applied before clipping begins. If a slider is pushed too far, the clipping is shown in bright pink.

 

 

 

 

To increase contrast within a tonal band, apply brightening and darkening simultaneously in equal amounts by dragging the upper and lower sliders up and down, respectively. The area between the top of the upper graph and the bottom of the lower graph indicates the amount by which contrast is increased.

To use the Standard tab:

  1. Do one of the following:
    • Drag the tone band sliders up or down depending on which light bands you want to adjust.
    • Type the exact number into the number boxes or increment the numbers to make precise adjustments.
    • Click the # Tone Bands drop-down list to increase or decrease the number of tone band sliders.
    • Click the Auto button to apply settings automatically.
    • Drag the Brightening slider to lighten the dark areas of the image.
    • Drag the Darkening slider to darken the light areas of the image.
    • Drag the Contrast slider to increase the contrast in the image.
    • Drag the Fill Light slider to lighten dark areas of the image.
    • Left-click and drag upwards to brighten the dark areas of the photo. Try to prevent clipping (shown in pink on the graph).
    • Right-click and drag downwards to darken the bright areas of the photo. Try to prevent clipping (shown in pink on the graph).
  2. Do one of the following:
    • Click OK to accept your changes and close the panel.
    • Click Cancel to discard your changes and close the panel.

The Advanced Tab

Sliders

The Advanced tab has two sliders for brightening (Amplitude and Custom curve) and two for darkening (Amplitude and Custom curve). The Custom curve sliders control the shape of the adjustment curves, while the Amplitude sliders control the height of the curves.

The more brightening or darkening, the more the balance of the dark against the light areas is increased in the image. The Amplitude sliders increase the intensity of the effects of brightening or darkening.

The Scale slider at the bottom of the tool adjusts the overall adjustment sensitivity to local variation in brightness. Moving this slider to the left makes the adjustment more sensitive to smaller areas of brightness variation, which may be beneficial in some images. For most images, however, leaving the slider in the default position gives the best result. Adjust the Contrast slider to decrease or increase contrast, or use the Fill Light slider to lighten dark areas of the image.

Graphs

Between the Brightening and Darkening controls are two gray graphs that indicate the maximum amount of lightening or darkening that can be applied before clipping begins (shown as bright pink).

Two colored curves appear and change when dragging the Brightening, Darkening and Amplitude sliders — these curves indicate the amount of brightening and darkening applied throughout the tonal range of the image. Darker tonal areas are on the left, and brighter tonal areas are on the right. Moving the cursor over the image, a vertical line in the graph indicates the tone level of the area under the cursor within the tonal range. At times there are two lines because the tone levels for brightening and darkening are not necessarily the same. This is because brightening is sensitive to maximum color values while darkening is sensitive to minimum color values.

The Advanced tab is unique in that you can adjust the curves manually, either on the graph itself, or on the actual photo. Adjustments made on the photo are reflected in the curve on the graph. Adjustments made on the graph are reflected on the photo.

To increase contrast within a tonal range without changing the brightness, apply brightening and darkening simultaneously in equal amounts by dragging the upper and lower curves up and down, respectively. The area between the top of the upper graph and the bottom of the lower graph indicates the amount by which contrast is increased.

To use the Advanced tab:

  1. Do one of the following:
    • Drag the Brightening or Darkening sliders to adjust the bright or dark pixels. While dragging, a gray curve appears to indicate the adjustments.
    • Left-click and drag upwards to brighten the dark areas of the photo. Try to prevent clipping (shown in pink on the graph).
    • Right-click and drag downwards to darken the bright areas of the photo. Try to prevent clipping (shown in pink on the graph).
    • Drag the Scale slider to the right to make your adjustments more sensitive to smaller areas of brightness variation.
    • Drag the Contrast slider to increase or decrease contrast in your image.
    • Drag the Fill Light slider to add light to the dark areas in your image.
    • Make adjustments using any of the options in the table below, including on the image itself.
  2. Do one of the following:
    • Click OK to accept your changes and close the panel.
    • Click Cancel to discard your changes and close the panel.

Adjustment Options - Advanced Tab

Area

Action

Result
Sliders

 

Drag Brightening

To the right: Increases the lightening applied to the darker areas.

To the left: Applies brightening more uniformly to all areas of the image.

(The name of the slider changes to Custom curve when changing the curve manually or making adjustments on the image.)

Drag Darkening

To the right: Increases the darkening applied to the brighter areas of the image.

To the left: Applies the darkening more uniformly to all areas of the image.

Drag Amplitude (Brightening)

To the right: Increases the intensity of the brightening across all areas of the image. The height of the curve increases.

To the left: Reduces the intensity of the brightening and the height of the curve.

If the Amplitude slider is 0, no brightening is applied.

If the Amplitude is 100 - 200, the proportional amount of clipping increases.

In most cases it is not necessary to adjust amplitude.

Drag Amplitude (Darkening)

To the right: Increases the intensity of the darkening across all areas of the image. The height of the bottom curve increases.

To the left: Reduces the intensity of the darkening and the height of the curve.

Drag Scale

To the left: Makes the tool more sensitive to smaller areas of brightness variation.

This means that smaller areas can be adjusted independently. Generally the default scale of 10 gives the best result, but if an image contains small details that need brightening, a lower scale might give better results.
On Graph

 

Drag the graph (top)

Clicking and dragging up on the graph itself changes the graph. The graph represents brightening adjustments. The dark gray graph represents the maximum amount the graph can be dragged before clipping begins (displayed as pink).

The height of the graph represents the level of brightening applied at each tone level. (Tone moves from black on the left to white on the right.)

When you make direct brightening or darkening adjustments on the graph or image, the corresponding Brightening or Darkening slider changes to Custom curve. Adjusting the position of the slider after changing to Custom curve, discards all direct curve adjustments.

When make direct brightening or darkening adjustments on the graph or image, the corresponding Brightening or Darkening Amplitude slider changes to indicate the current curve amplitude.

Drag the graph (bottom)

The graph changes as you right-click and drag down on the graph itself. The graph represents the darken adjustments you are making. The dark gray graph represents the maximum amount you can drag the graph before clipping (pink) begins.

Use all the shortcuts below that apply to the image, directly to the graph itself.

Changes the tonal band on the graph itself with a corresponding change in the image. This is useful for making fine adjustments to a specific tonal band.
On Image

 

Double-click with left mouse button

Automatically sets Brightening to optimum for that area of the image. A brighter area (e.g. a face) works best.

Double-click with right mouse button
(or Shift + double-click with left mouse button)

Automatically sets the Darkening to optimum for that area of the image.

Ctrl + double-click with left mouse button

Increases the amount of brightening around that tone level while decreasing the brightening in the rest of the image.

Use this method to quickly brighten a specific subject or area to bring it out of the image.

Ctrl + double-click with right mouse button

Increases the amount of darkening around that tone level while decreasing the amount of darkening in the rest of the image.

Scroll up or down with the mouse wheel above the image

Increases or decreases the amount of brightening applied at that tone level in the image. Both the image and the graph show the changes.

Shift+ scroll with the mouse wheel above the image

Decreases or increases the amount of darkening applied at that tone level in the image.

Hold down "A"
+ scrolling or
+ dragging with the left mouse button

Sets the brightening Amplitude slider directly.

Hold down "A" + Shift
+ scrolling or
+ dragging with the right mouse button

Sets the darkening Amplitude slider directly.

Click and drag up and down on the image (left mouse button)

Increases or decreases the amount of brightening applied at that tone level in the image. Both the image and the graph show the changes.

(Only works if the image is actual size - no zooming.)

Shift + click and drag up and down on the image (left mouse button)

Decreases or increases the amount of darkening applied at that tone level in the image.

(Only works if the image is actual size - no zooming.)

Right-click a slider to reset to the default value.

This filter features a Pixel Targeting tab (see Pixel Targeting for more details).

Use the Edit Brush to paint this effect onto specific areas of the image.

Use the Gradient tool to transition this effect across specific areas of the image.

Use the Radial Gradient tool to apply effects around, or directly to, a center point.

See also: