Burning and Dodging with Contrast

One of the more interesting techniques to come out of the TK8 plugin, I think, is a new method to burn and dodge images in a way that enhances contrast instead of just globally lightening and darkening all pixels that receive paint. 

The traditional way to burn and dodge

The most common method to burn and dodge an image is to fill a blank pixel layer with 50% gray and change the blend mode to Soft Light or Overlay.  Then paint on the layer using black or white paint.  White paint increases the brightness of underlying pixels and black paint decreases the brightness of the underlying pixels.  50% gray is transparent in these blend modes and has no effect on the underlying pixels. Brush opacity can be adjusted to control the strength of the effect.

The image below demonstrates what happens with this type of burning and dodging. White paint, 50% gray paint, and black paint are applied to Burn and Dodge layers created with the TK8 plugin, which automatically sets the appropriate blend modes.   The brush opacity was set to 100% for this example. 

The “White brush” line shows where white paint was applied to a 50% gray layer set to Overlay blend mode. The strongest effect appears at the center of the gradient with highlights and shadows being affected somewhat equally as you move away from the center.

The “Black brush” stroke was applied to a 50% gray layer set to Soft Light blend mode.  Here it looks like the dark tones are slightly more affected than the light tone, though the tonal darkening extends all the way to the edge of the brightest highlights.

As expected, the “Gray brush” stoke shows no change since 50% gray paint is transparent in Overlay and Soft Light blend modes. 

The “Paint Contrast” method

The TK8 plugin has an action in the Combo and Cx modules called “Paint Contrast.”

It creates a “Paint Contrast” pixel layer set to Hard Mix blend mode and 15% Fill.  There is no “transparent” color in this blend mode, so it’s not possible to fill the layer with 50% gray paint and have the image remain unchanged. 

The image below shows what happens when the same white, 50% gray, and black brush strokes are applied to this layer.

The “White brush” stroke created a change in pixel brightness that is more pronounced in the brighter tones of the gradient.  There is still some additional brightness added in the dark tones, but it is less than the amount added in the light tones.  As a result, there is increased contrast.  The light tones have gotten lighter faster than the dark tones and this creates greater tonal separation between highlights and shadows.

The “Black brush” stroke shows the opposite effect.  The shadow tones have become darker while the highlights are barely affected.   Again, this results in increased contrast.  Darker tones have gotten darker faster than the lighter tones so there is greater tonal separation across the gradient. 

The “Gray brush” stroke increased contrast in both the light tones and the dark tones.  The shadows have gotten darker and the highlights have gotten lighter.  Neither change is as strong as with the “White brush” or “Black brush,” but it’s easy to see the added contrast on both the light and dark sides of the gradient.

Improved texture: A practical use of “Paint Contrast” for burning and dodging

One way to increase local texture in an image, especially a nature scene, is to selectively darken specific shadow areas (burn them) and lighten specific highlights (dodge them).  Generally, this is best accomplished using a tablet and stylus (instead of a mouse, as somewhat exacting control is necessary) along with traditional burning and dodging techniques using a 50% gray layer.  Lights and Darks luminosity masks can help select the right tones, but it’s often easier to just free-hand burn and dodge with a small, low-opacity brush on those areas where local tonal changes are desired.  When done well, there is added local contrast that brings out the textures already present in the image.

Using a “Paint Contrast” layer for burning and dodging makes this process easier, especially if all you have is a mouse (instead of a tablet and stylus).  Painting black or white onto a “Paint Contrast” layer preferentially selects the tonal range that matches the paint.  Highlights get lighter with white paint and shadows get darker with black paint.  The opposite tone is minimally affected, and the end result is again that added local contrast is created that brings out the textures already present in the image.  A smaller brush or even a luminosity mask selection might be useful in some situations, but good results are also possible with just free-hand painting with a moderately large brush over the tones that you want to affect. Using “Paint Contrast” makes it easy to add texture to the image because the paint color (white or black) automatically selects the best pixels for increasing contrast.

NOTE: While it’s possible to paint with gray paint to increase contrast in both light and dark tones, this sometimes gets a confusing.  Using just black and white paint will simplify the process of burning and dodging with this technique.

Additional controls

Below are some additional options to fine-tune burning and dodging with contrast.

Brush opacity—Not surprisingly, brush opacity is one of the main controls.  It’s better to start with low brush opacity and then use multiple brushstrokes to slowly build up the effect.  A brush opacity of 5 to 10 percent is a good starting point for adding white paint and 10 to 20 percent for black paint. Brush opacity of 100% was used to create the demonstration image above, but that’s definitely too strong for actually adding this technique to your workflow. Increased contrast and texture are still achieved with a low-opacity brush.

Use a separate layer for white and black paint—This helps keep the dodging and burning confined on separate layers.  The “Paint Contrast” action in the TK8 plugin always gives the newly created layer the same name (“Paint Contrast”), so it’s helpful generate and label one for white paint and another for black paint in order to keep things straight.

Layer Fill opacity—Hard Mix blend mode is one of those where the Fill opacity can be used to increase or decrease the effect.  To make it stronger without adding additional paint to the layer, increase the Fill opacity.  However, 25% is about the maximum that works.  Above this level, the brush strokes start to become more obvious. Lowering the Fill opacity will, of course, decrease the effect.

The Eraser tool–Since there is no paint color that is transparent in Hard Mix blend mode, the way to remove this effect is with Photoshop’s Eraser tool. Setting the Eraser tool’s opacity to less than what was used for actually adding paint to the layer allows the effect to be erased gradually with multiple brush strokes, which can facilitate better blending.

Summary

Using a “Paint Contrast” layer adds a new dimension to the burning and dodging process.  Additional contrast is added as you burn and dodge and increased local texture is the result.  Since the choice of where to apply paint and how much to apply is up to the photographer, the final results are always quite individualized.  The effect often seems quite subtle because the blending of the paint strokes into the image is so good. However, when you turn the “Paint Contrast” layer off and on a couple of times, then the real power of this technique can be seen. 

Dave Kelly demonstrates burning and dodging with a “Paint Contrast” layer in the workflow tutorial linked below. There are several useful TK8 techniques shown throughout the video. Burning and dodging with contrast starts at 23:00.