Benefits
of the plug-in

Full control over black and white contrast
Preserve or remove mid tones to any degree
Balance the amount of lights and darks to correct exposure
Quick general contrast integrates color contrast and black and white contrast
Target to any range of brightness or color

The Contrast Editor plug-in works with these image modes (Windows and Mac)...
8 & 16 bit: RGB, Grayscale, Duotone, CMYK, Multichannel, Lab.

Contrast Editor
filter controls

Here's the Contrast Editor plug-ins controls (Mac). Click the image to enlarge. The control panel and preview area can be resized by dragging the edges.
The plug-in divides its contrast editing into three groups:
1. General Contrast
2. Black and White Contrast w. mid tone control
3. Color Contrast

In addition there are control groups for restricting filtering to a brightness- or color-range or a graduated effect

Example -

Gain control over
every aspect of contrast

What is contrast control?

Expand range?

Or don't Expand range?

The Power Retouche contrast editor gives you the option to enhance contrast with control of if, and how much, the brightness range should be expanded. You could preserve it as the original and yet still enhance contrast - I believe Power Retouche Contrast Editor is the only contrast editing system that gives you that possibility.

You can only do that if you can push the mid tones towards the extremes so there is more of the dark and light - but without making the darks any darker or the lights lighter.

Don't preserve mid tones

Preserve mid tones?

Power Retouche Contrast Editor even combines the above possibilities and lets you control range expansion and mid tone preservation at once.

The General Contrast control

General Contrast

This is Power Retouche's integration of black/white contrast with color-contrast. This slider edits contrast of hue, saturation and brightness-range while preserving the relationships between the three. The example to the right was filtered with the General Contrast at 100%.

Technically (in the terms of the Munsell color space notation) where black-white contrast moves individual colors vertically up or down a value axis, and saturation moves the individual colors horizontally along a chroma axis, our General Contrast will move individual colors diagonally along both simultaneously. This direction has no given name, though it is so central for any practical color adjustment. For the lack of a name, in either Munsell or The Uniform Color Scales of Optical Society of America, we simply named it by its apparent effect: General Contrast.

The truth behind the lacking term is that it in reality its a bit more complex than a simple diagonal line. The visually - and optically - correct change is not achieved by a linear diagonal shift, but rather by a logarithmic curve - with curvature, start- and end-points varying from hue to hue.

See another example of retouching with general contrast alone at the bottom of this tutorial.

Black/White Contrast

B/W contrast %

The B/W Contrast slider determines how much change should be applied. How the contrast is changed is set by the following two sliders, so the aesthetic effect of this slider is determined by them.

This sliders effect also enhances the effect of general contrast.

Black Alert and White Alert will display a uniform color in the preview in those areas that clip 0.3% towards pure black and 0.3% to pure white. You can change the color of the alerts by clicking in the colored rectangle displaying the color of the mask.

Preserve mid tones %

This slider determines how much the contrast should be changed by altering the contrast of the mid tones.

At the extreme you can split the image into just black and white. Normally you will think in terms of preserving the mid tones rather than enhancing contrast by separating them.

Balance

Balance changes the ratio between light and dark in the image.

Expand range

These sliders determine if and how much the dynamic range should be expanded - in other words how much the contrast should be changed by making the darks darker and lights lighter.

Color contrast

This group of controls is straight forward.

Warm contrast targets warm colors (yellow, orange, red).

Cold contrast targets cold colors (cold green, cyan, blue, violet).

Red, Green and Blue contrast target the respective colors.

Levels

The luminance levels are common to most Power Retouche plug-ins. They let you determine the degree the filtering will be applied to lights, mid tones and darks.

Saturation levels determine how much changes should be applied to saturated or unsaturated colors.

Graduated effect

These controls are common for many of the Power Retouche plug-ins. Using graduated effect will cause the filter to apply it's filtering at full strength in one side of the image and then fade the effect out towards the other side. You can change direction by right clicking the preview. Midpoint will shift the balance between how large an area will be filtered at full strength and how much will have a faded out effect. Contrast will change the acceleration and spread of the fade-out.

In these two examples we applied a graduated effect towards the bottom. The original is flat because there is not enough contrast in the foreground objects (or more exactly: more contrast in the foreground objects compared to the background). We raised general contrast and warm contrast. Note how much greater the depth is after this elegant retouch.

Ranges

The ranges tab opens the ranges controls. This is common for most Power Retouche plug-ins.

Their controls are described below.

The Mask unchanged checkbox is an aid to setting the limit-sliders. It applies to both the brightness-range and the color-range. When checked, areas of the image that are darker than the dark limit or lighter than the light limit will be shown in the preview as a uniform color. You can change the color of the mask by clicking in the small rectangle.

Brightness Range

Brightness-range

The following sliders become active when the "Use Brightness Range" is checked. This set of controls is common to most of the Power Retouche plug-ins.

Dark Limit

This slider tells the filter not to alter areas of the image that are darker than the sliders setting (0=black, 255=white).

Light Limit

This slider tells the plug-in not to alter areas of the image, that are lighter than the sliders setting (0=black, 255=white).

Target

This tells the plug-in which value between the dark and light limits shall be changed the most.

Color Range

From &
Up to

Color range filtering is common for most of the Power Retouche plug-ins. Color range will restrict filtering to colors in the range from the right side of the "From" slider to the left side of the "Up to" slider. This means that all color-selections are possible, since if you place the From slider to the left of the Up to... slider, then colors in between the two controls will be edited. If you place the From... slider to the right of the Up to... slider, then colors in between the two controls will not be edited.

Below is an example where we blocked out a blue sky - and to the right is how the mask appears...

Softness

Softness determines to what degree the values in the range shall be edited at, and around, the middle value.
0% = full effect in whole range.
100% = only full effect on middle value.

Example using color range

Invert selection (Inv.)

This will make the sliders swap place. For example you might have set the sliders to include only reds. If you press Inv. the sliders swap place and you have selected everything but reds.

This is useful, for example, if you first want to edit selected foreground colors, then rerun the plug-in to edit all other colors. The plug-in remembers your settings between invocations, so on the second run just hit Inverse.

The two small colored rectangles show the selected color. If you use the brightness range the color in these two windows will become lighter or darker according to the selected range.

Histogram, Anti-posterization and Color values

Histogram

Anti-posterization

Pixel data

These controls are common to most of the Power Retouche plug-ins. The displayed histogram will be for the area in the preview. You can choose between individual color channels, all color channels or luminance.

Anti-posterization should be set as low as possible. In most cases leave it off (at 0) in order to speed up processing time.

The color picker allows you to pick a point (pixel) in the preview and get some interesting data about it. The d-values tell how much the pixel is changed in percent. L tells the luminance value (brightness) of the pixel.