FAQs About Lumnosity Masks

Several people have written to ask questions about the luminosity masks techniques that I’ve posted in the Photoshop tutorials section on my website. I always try to respond to these inquiries and have saved several of the exchanges. Recently I edited the questions and answers to make them more informative and posted them in a FAQs About Luminosity Masks tutorial. This tutorial takes the themes of the various questions and uses the answers along with some illustrations to provide more in depth information on how to best use the luminosity masks with the goal of providing additional information to interested photographers. Below are the questions. By clicking on one a new window should open that links to the answer in the tutorial. Once on the site, there is a “Return to questions” link after each answer if you’d like to peruse the other questions and answers. I hope this information is useful. Please feel free to contact me if you have additional questions.

#1: The entire image seems to be affected when I do an adjustment with one of the luminosity masks on a Curves adjustment layer, not just the tones I want to adjust. Why is this?

#2: How do I decide which luminosity mask to use?

#3: I see in your examples that you mostly use Curves adjustment layers when using the luminosity masks. Why not use Levels?

#4: It seems like luminosity painting does the same thing as using the luminosity masks on Curves adjustment layers—adjusting the brightness and contrast of specific tones in the image. Is there an advantage of choosing one method over the other?

#5: There are two sets of actions, TK-LumMasks(Channels) and TK-LumMasks(Layers). How do I know which set to use?

#6: I read about the subtraction masks that you had created and wondered if it would be possible to email them to me as actions?

#7: What workflow do you recommend when using the masks?

Edge-burning by Luminosity Painting through the Basic Mid-tones

Note: This post builds on information presented in the Luminosity Masks and Luminosity Painting tutorials located on my website. Some familiarity with the techniques in these articles will be necessary to understand the edge-burning process presented below.

Ansel Adams in his book, The Print (Book 3 of The New Ansel Adam Photography Series), offers this insight about edge-burning, a process for slightly darkening the edges of a print:

“Mounting or overmatting a print with white board has a tendency to produce a faint ‘flare’ effect around the border, where the image may appear slightly weak. This is a visual effect only. A slight burning of the edges of the image seems to ‘set’ it in the mount and helps to hold the eye within the format.” Adams then goes on to describe two methods for edge-burning in the darkroom.

While true darkrooms, like those in which Adams created his art, are increasingly uncommon, the concept of edge-burning is still sound. Judiciously darkening the edges of a print can not only alleviate the “faint flare effect” from white board mentioned by Adams, but it can also provide increased visual appeal regardless of where the print is presented. Edge-burning subtly keeps the viewer engaged with the image by preventing the their eyes from drifting out of the frame, and it’s effective with web-based images, framed pictures, and even loose prints.

Edge-burning should be distinguished from the common term, “vignette.” A vignette is usually more perceptible, as in lens vignetting, where there is obvious fall-off of light at the edge of the frame. Alternatively, a purposeful vignette may be added to an image to create overtly dark edges as a way to add style or emphasis. Vignettes can easily be corrected or added in Photoshop via the Lens Correction filter (Filter > Lens Correction). Most RAW converters also have a vignette functionality that provides users an easy method for dealing with vignetting issues.

While the automated vignettes in image-processing software can be useful for edge-burning, each image has its own distinct needs and will often require a more individualized approach. For example, some edges may need more burning than others and the amount of burning may also be variable along any given edge. Additionally, the “depth” of the burn into the frame may need to be adjusted depending on the elements in the picture and where they are located.

My preferred approach to edge-burning is to use luminosity painting through a selection of the image’s basic mid-tones. Luminosity painting allows me to place the edge burn exactly where I want it and to build it up to whatever degree is needed for a particular section of the image. The image below is one where edge-burning was helpful in creating the final tonal balance of the image. Rolling the mouse over the image will show what it looks like with the edge-burning removed. (It may take a moment for the second image to load, but once it does, you should be able to pass the mouse back and forth across the edge of the frame to flip the edge-burning on and off.)

When looking at this image initially (no rollover), the edge-burning is not obvious. It’s meant to blend into the image in an almost imperceptible manner. However, removing the edge-burning (rollover) makes a very noticeable difference. Once gone, the eyes are drawn more to the lighter edges of the frame, and the visual focus on the balanced rocks is lost to some degree. While the rocks are obviously the focal point in the image, edge-burning effectively creates a tonal congruence to help establish this fact. What the eye perceives is now reinforced by the tonal values in the image.

Below is the what the burn/dodge layer looked like after painting through the basic mid-tones mask to create the edge-burning for this image. As a reminder, this layer is 50% gray to start with and is set to Soft Light blending mode. Painting black on this layer darkens the underlying tones to create the edge burn. So the areas darker than 50% gray represent places where burning (darkening) occurred. As you can see, not all edges were treated the same. In some places no burning was required. In others it’s quite heavy, and in still others very light. The depth of the burning from the edge is also variable. The goal was to create an appropriate edge burn in response to what the image needed.

The question might logically be asked, why is it necessary to paint through the basic mid-tones selection for edge-burning? The short answer is: It works! I’ve tried painting through both Lights-series and Dark-series selections and no selection at all, but keep coming back to the basic mid-tones. The reason–painting through this selection has the desired and predictable effect regardless of whether the edge is light or dark. A more technical answer would be that by targeting just the mid-tones for edge-burning, the lightest values aren’t grayed down and the darkest values don’t lose texture. As such, overall image contrast isn’t significantly affected by painting through the basic mid-tones, so the image still retains the look it had before edge-burning. This is very important. Remember, the goal is to be subtle with this technique; the effect should not be obvious or look out of place.

From a workflow standpoint, I first create the burn/dodge layer. Then I create the basic mid-tones selection or load it from the corresponding mask I’ve made on the Channels palette/panel. I usually start edge-burning by using a soft brush and black paint set at 25% opacity. I adjust the opacity up or down depending on how much burning is required. If it goes too far (the burned area gets too dark), I change the brush color to white and lighten things up again. Some parts of the image may require several brush strokes in order to be properly darkened. Painting is an extremely versatile technique so there is a great deal of latitude built into the process. In the end, it will be entirely up to me to decide how the edge burn should look. Fortunately, even with heavy burning, the blending of the burn into the image will be perfect. Painting through a luminosity mask insures this.

Below is another image that was edge-burned through the basic mid-tones. Again the rollover is the image with the edge-burning removed.

This image is more abstract than the previous one and there is no obvious focal point. Still, the edge-burning enhances its viewability. While there is no noticeable vignette, the slightly darkened edges keep the eye in the frame to explore the shapes and textures. So even though this is an abstract image with a rather monochrome color palette, edge-burning makes it more coherent. The technique provides a better balance of light across the frame, and as such, it plays an important role in image’s final presentation.

The burn/dodge layer for this image’s edge-burn is shown below. Again, the amount and coverage of the edge burn is quite variable within the frame and is specific for this image. Luminosity painting is an ideal way to create this individualized effect for each image and to vary it depending on your personal preference.

“My experience indicates that nearly all photographs require some burning of the edges. The edge-burning must not be overdone, however; the viewer should not be conscious of it.”

This was Adams’ last statement with regard to edge-burning in his book, and I agree with it. Most images do look better with some edge-burning, but keeping it subtle is key to doing it successfully. The digital darkroom makes available a much more nuanced approach than could be accomplished by Adams’ in his darkroom, but the intent and effect are still the same. I think it’s a nice finishing touch to add to an image and hope you’ll give it a try.

Saturation Painting

Saturation masks can be a useful addition to the Photoshop toolkit. The Vibrance adjustment panel in Photoshop CS4/CS5 can make global adjustments to saturated colors and unsaturated colors (vibrance), but targeting saturation adjustments to specific colors and specific levels of saturation can be a bit more challenging. Saturation masks can help do this. I recently added a tutorial that describes one method to paint saturation and vibrance into specific parts of an image and to target either saturated or unsaturated colors when doing so. In some ways it resembles luminosity painting, but instead of changing the brightness of specific tones, saturation painting adjusts color saturation, either increasing it or decreasing it. The image below is one that included the saturation painting technique. If you roll your mouse over the image you’ll see how it looks with the saturation painting layer turned off.

The saturation painting effect is subtle but important in bringing better saturation balance to the image. The most obvious change is the increased saturation in the yellow-orange trapezoid at the top right. This area was more heavily painted to make a more dramatic saturation change. Lesser changes can also be seen however. On the left side of the image, saturation was decreased, but just slightly to take the edge off the over-saturated colors in this area. Also, on the right and moving towards the center, saturation was again increased, but not nearly as much as in the trapezoid. These last two changes, being more subtle, required less paint to achieve the desired results. That’s one of the advantages of saturation painting–the degree of saturation change can easily be altered simply by changing the amount of paint that’s applied.

These saturation changes were accomplished using the brush tool on a single layer in Photoshop. Below is what this layer looks like.

The tutorial that describes this technique is located here.

Softening Contrast, Balancing Light

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.

Soften Contrast action set

Falling Down

The image below was taken in 2006.

I visited again this spring and found that the formation is starting to crumble. The image below shows that the leftmost, red-capped rock has fallen from its perch and now lies at the base of the formation. In October 2009, everything was still intact (see picture in previous post), so this happened over the winter. It was an extremely wet winter here on the Colorado Plateau. It’s possible that the amount of moisture that saturated the rock along with the freeze/thaw cycles that accompanied the winter’s El Niño precipitation was enough to topple the rock. It’s hard to know for sure what actually caused the rock to fall, but it appears to be from natural causes as it would be very hard to reach this place to deliberately push the rock off its pedestal. While the iconic sense of the place remains, the character is definitely changed. The balance that this one rock provided to photographs is now quite obvious. Also quite obvious is the fact that the balance of the rock has been precarious for quite some time. Inevitable though it may be, it’s sad to see it go.

While I certainly wasn’t the first to photograph this place, I do happen to be aware of its photographic origins. I worked with Dr. Scott Lybrook (Google him) when I worked in Tuba City. He was an explorer and was the first to “find” this place and realize its photographic potential. He shared its location with Michael Fatali. Soon thereafter Fatali released Once Upon a Time, which quickly became the defining composition, though it was taken lower down and sort of hides the rock in back. Over the years the place has been sought and photographed numerous time. Dr. Lybrook, however, was the one who got it all started.

Cloud Sharpening

I don’t take a lot of images with clouds, but when I do, I usually try to give the clouds a little extra sharpness to emphasize their edges and textures. Doing so seems to help the clouds to better match the sharpness in other parts of the scene and makes them a bit more visually appealing.

The image below shows a scene without cloud sharpening. Roll the mouse over the image to see the subtle improvement cloud sharpening can provide. It’s very subtle, especially in the jpg. Look closely at the edges of the clouds. There is greater texture which slightly increases the drama in the sky.

I’ve posted a cloud-sharpening tutorial on my website to describe how I do this. There are many ways to accomplish a particular task in Photoshop, and I’ve received feedback from others that they have their own cloud-sharpening methods. Please feel free to add a comment about what works for you if this is something you’ve tried.

The image below is another where I felt cloud-sharpening was useful. The mouse rollover again shows the cloud-sharpening effect. You may have to look close to see it, but the cloud-sharpened image better captures the raggedy nature of the windblown clouds that were happening this day.

As with everything in Photoshop, there are many variations to the cloud-sharpening process that can be applied to maximize the results. These are described in the tutorial as well. Also, some users have written to say they’ve used this technique to successfully sharpen water, leaves, and small branches. I hope you’ll give it a try.

My Favorite Photoshop Technique

Thanks for stopping by. Like many people who enter the blogosphere, I’m not entirely sure what I’ll be saying here as time goes by. My current intentions are to use this space to elaborate on some of the techniques I use in the digital darkroom and to reply to some of the comments and questions I’ve received regarding the tutorials on my website.

I’d like to start by discussing my all-time favorite Photoshop technique, which would be luminosity painting. This technique is perhaps the most powerful way of using the luminosity masks. Painting leverages the potential of the masks to a much higher degree than simply using them as masks on adjustment layers. Painting allows both multiple brush strokes to intensify the effect of the luminosity mask and precise placement on the image to provide perfect control as to which parts of the image are affected.

Simply put, luminosity painting is burning (darkening) and dodging (lightening) an image by painting through a luminosity mask tonal selection. It involves three steps:

1. Create a Burn/Dodge layer in Photoshop—New layer>fill with 50% gray>change blending mode to Soft Light.
2. Create a selection to target the desired tones, that is, make a luminosity mask. (Before painting, it’s helpful to turn off the marching ants by typing Ctrl+H (Windows) or Command+H (Mac).)
3. With a paintbrush, paint through this selection onto the Burn/Dodge layer. Paint white to lighten (dodge) the underlying tones and paint black to darken (burn) them.

There are all kinds of variations within this process that increase your control over how the image is affected—the tones that are selected by the luminosity mask; the shape, size, and hardness of the brush; the opacity of the brush stroke; and number of brush strokes are some examples.

While there can be many aesthetic reasons for using luminosity painting with an image, my personal goal is usually to use it to bring a certain degree of balance to the overall light and contrast in the scene. This is a very personal decision, and everyone is free to decide and create their own personal balance of tones using this painting technique. Here’s an example how it was used in a recent image.

The image below shows the final version of an image after it had been luminosity painted. A mouse rollover of the image shows what it looks like with the luminosity painting removed. Hopefully you can see and appreciate how the painting increased the brightness of some areas and darkened others, while at the same time maintaining overall contrast and slightly improving saturation.

The next three images show the painted Burn/Dodge layers that were used for luminosity painting. The first shows painting to bring down the highlights in the scene. Black paint was first applied through a selection of the Bright Lights minus the Super Lights. When it was found that some of the brightest tone still were too bright, a new mask, call it the Super-Duper Lights, was created by intersecting the Super Lights mask with itself. Though I’d not tried this mask before, it worked very well here for painting through to bring the lightest tones down to where I felt they looked right.

The second Burn/Dodge layer (below) was used to paint both black and white through a Basic Mid-tones selection. Parts of the image were darkened with black paint and other parts were lightened with white paint. Painting through a Basic Mid-tones mask is an easy place to start luminosity painting. The changes occur in the mid-tones and the result is usually improved contrast in the image. While I put no limitations on the masks I’m willing to paint through, it’s surprising how many times painting through the Basic Mid-tones mask is part of the process.

The final Burn/Dodge layer for this image (below) was painted on through a Light Lights mask intersected with a Darks mask. Intersecting a Light-series mask with a Dark-series mask can be a bit tricky. You’re basically restricted to the Expanded Lights, Lights, and Light Lights in the Lights-series and the Expanded Darks, Darks, and Dark-Darks in the darks series. In this case I wanted to do two things: darken some of the slightly too light tones at the upper end of the mid-tones at the top of the arch and lighten some of the dark areas of rock on the right side of the image to give more texture and contrast here to better balance the texture and contrast on the leafy left side of the image. This intersected mask just happened to work well to accomplish both goals with the black paint darkening the too-light areas at the top of the arch and white paint lightening and bringing out more texture on the right side of the image.

NOTE: Instead of three separate layers, all this painting could have been done on a single Burn/Dodge layer.

These painted layers are instructive as they show several important characteristics of luminosity painting. What should be most apparent is that parts of the image appear to be embossed in gray-scale onto the layer. This is the direct result of painting through luminosity selections/masks which select specific tones to receive paint. Areas darker than 50% gray darken the underlying tones in the image and areas lighter than 50% gray lighten the underlying tones. Applying paint through an active luminosity selection both selects the pixels that receive paint and darkens or lightens these pixels as the paint is applied. Because luminosity selections partially select pixels in proportion to their brightness, paint is also applied proportionally as the brush is stroked across the Burn/Dodge layer. The net result is not only that the tones in the desired parts of the image are changed, but the change is also perfectly blended into the surrounding pixels. (The partially selected tones receive the exact amount of paint to make sure each brush stroke merges seamlessly with similar tones.) Brush strokes can be applied repeatedly until the desired change is achieved in the specific parts of the image where the change is desired. By choosing the correct mask or combination of masks to paint through, significant control can be exercised with regard to the final brightness and contrast of the painted areas.

The only way to really get a feel for what luminosity painting can do for an image is to try it. A good place to start is to load the Basic Mid-tones as a selection and try darkening and lightening parts of the image by painting black and white respectively onto a Burn/Dodge layer. Start with a brush opacity of 50 to 100 percent since the Basic Mid-tones mask is quite dense and it will sometimes take a lot of paint to make noticeable difference on the image. Once you get a feel for what’s happening when painting through the Basic Mid-tones, try masks from Lights- or Darks-series to see how painting through these can select specific tones for adjustment. Experiment. See what happens, figure out what’s going on, and then make it work for you.

Luminosity painting allows you to touch the light in your image and make very precise adjustments to specific tones. The decisions you make in luminosity painting are completely personal. You decide what needs adjustment, and then you make the adjustment to your satisfaction. It’s your hand on the mouse (or pen), it’s your brush strokes on the image, and it’s your idea of how the image should look. To some degree, you are actually inscribing your signature into the image’s pixels as you paint, personalizing your image with a signature look. I hope you’ll give it a try.