Getting the contrast right in an image is very important. If the overall contrast is right, the image will look good in a variety of light conditions. Bright light, shady room, dim light, it doesn’t matter. Once the contrast is properly adjusted, the picture comes through just fine in many different light situations.
If a picture doesn’t quite look right after it’s printed, looking at it in different light can sometimes help to figure out what’s wrong. My normal viewing light for prints is two halogen lights over a long counter. Not surprisingly, almost everything looks good here. The warm, bright light lets me see all the shades of color and texture in the image, and this usually matches quite well what’s on my calibrated monitor. However, moving the print to the living room, which is dimmer, or next to window with north light can sometimes change things. The image may look underexposed, or flat, or contrasty. When this happens, it’s a clue that the contrast might not be adjusted quite right.
Photoshop provides many different ways to adjust contrast. An “S” curve on a Curves adjustment layer is a common way to increase contrast. A “backwards S” curve can be used to lower contrast. The Levels, Brightness/Contrast, and Shadow/Highlight adjustments are additional tools to help manage contrast. On a couple of recent images the contrast was a little too strong and these usual methods weren’t working to make the prints look right. So I tried a technique that combined using a blending mode with a luminosity mask. It seemed to work well on both images, and I’d like to share it with you.
The header for this blog is one image where the technique was used. Below is the final version of this image. Roll over the image with the mouse to see how it looked before the contrast adjustment.
Here are the steps used for softening contrast in this image:
Step 1—Create a new blank layer at the top of the layer stack and fill it with the current state of the image. The easiest way to do this is to type Shift-Alt-Ctrl+N followed by Shift-Alt-Ctrl+E on Windows or Shift-Opt-Cmd+N followed by Shift-Opt-Cmd+E on Mac. (In CS3 and CS4, you can just type Shift-Alt-Ctrl+E or Shift-Opt-Cmd+E to perform this step.) If the new layer isn’t at the top of the layer stack, drag it there.
Step 2—Desaturate the image using the menu command Image>Adjustments>Desaturate. (Keyboard shortcut=Shift-Ctrl+U on Windows and Shift-Cmd+U on Mac.) The image should look like a black and white positive when finished.
Step 3—Invert the image using the menu command Image>Adjustments>Invert. (Keyboard shortcut=Ctrl+I on Windows and Cmd+I on Mac.) The image should look like a black and white negative when finished.
Step 4—Blur the image using the menu command Filter>Blur>Gaussian Blur. Set the radius around 35 pixels for images from cameras 12-megapixels and larger. Use a smaller radius for smaller cameras. The image should look like a blurry black and white negative when finished.
Step 5—Change the blending mode of the layer to Soft Light. Click the drop-down menu in the upper left of the Layers palette/panel and choose “Soft Light” from the list. Soft Light blending mode lightens areas that are lighter than 50% gray and darkens those that are darker than 50% gray. Because this layer is now a blurry negative of the image, the dark areas of the negative (which are the light areas of the actual image being worked on) will darken and the light areas of the negative (which are the dark areas of the image) will get brighter. After choosing Soft Light blending mode, the negative disappears and the image reappears. However, the contrast and saturation of the image are significantly decreased. There may be a grayness to the image that’s not too appealing.
Step 6—Lower the opacity of the layer (upper right corner of the Layers palette/panel) to restore contrast and saturation to the appropriate /desired level. This will vary with each image, but will almost always be less than 100%. Alternatively or additionally, a mask can be used to restrict the contrast change to specific areas or tones in the image. In the image above, the opacity was set to 90% and a Basic Mid-tones mask was used to further filter the effect.
The image below is the second image where this technique was used. The mouse rollover once again shows how the image looked before the contrast was softened. Here the opacity of the blurred layer was decreased to 40% and then a Shadow Darks mask was added to restrict the contrast change to the darker areas of the image. (See Luminosity Masks for a description of the various masks.)
I like this technique because it has a nice “light balancing” effect. The darks get lighter and the lights get darker in a way that can potentially better balance the overall light and contrast in an image. I also like how the effect perfectly matches what’s happening in the image. That’s because the new layer used to make the adjustment starts off as a duplicate of the image, so everything that happens in the process mirrors that image. This makes the final adjustment of opacity or the addition of a luminosity mask relatively easy since everything is already “lined-up” pixel-wise in the image.
If you’d like to experiment with this technique, the “Soften contrast action set” link below provides a downloadable action set that does most of the steps. When the action finishes running, you’ll still need to adjust the layer’s opacity and maybe add a luminosity mask to restrict the adjustment to specific tones. There are two versions of the action in the action set. The “single-layer” version does all the steps on a regular pixel-containing layer in Photoshop. The “smart-object” version performs the steps on a smart-object layer. This allows you to change the amount of blur by double-clicking the “Gaussian Blur” area of the layer and choosing a different pixel radius. I hope you’ll give it a try.