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Saturation Masks 1: The problem with Photoshop’s HSB/HSL filter

May 17, 2018

In addition to my work advancing luminosity masks, I’ve also been a big proponent of saturation masks. I’ve used them since 2007 when I first started writing about saturation masks and saturation painting. The way I originally recommended making them was Adobe’s HSB/HSL filter. However, Adobe stopped including the filter in Photoshop for a number of years, so I changed to a different and ultimately better method to make saturation masks. Adobe has again included the HSB/HSL filter in the Filter menu of Photoshop CC. Now that it’s returned, this is probably a good time to review why it should NOT be used to make saturation masks.

TK Basic V6 panel

The way to run the HSB/HSL filter is to create a stamp-visible layer of the image and then convert it to HSL (Hue, Saturation, Lightness) with the filter. Once this is done, the new “Green” channel is used as a saturation mask. Sounds easy, but it’s flawed. A saturation mask created by this process poorly matches the saturation in the image, especially for dark colors.

This first blog covering saturation masks will take a closer look at the HSL/HSB filter and the asymmetry problem associated with it. It’s helpful to understand the problem before moving on to the solution. To do this, I’ll use a Granger Chart, shown below, for illustration since it makes the HSB/HSL problem quite obvious. A copy can be downloaded here. (NOTE: There are some color artifacts in the image on this blog as a result of converting from ProPhoto to sRGB for display on the web.)

TK Basic V6 panel

In the Granger Chart, the most saturated colors zigzag across the vertical center of the image. Saturation will vary somewhat depending on hue, but moving vertically, either up or down away from the center, leads to colors with decreased saturation. The saturated colors in the middle gradually transition to 100% white on the top and 100% black at the very bottom. Black and white have no color at all and so, by definition, are completely unsaturated (saturation = 0%). In other words, pixels close to the center are highly saturated, and saturation decreases in a gradual manner as you move towards the top and bottom edges.

And this is indeed what happens according to Photoshop’s Color Picker when moving vertically from the center to the top edge. The image below shows saturation values from the Color Picker at evenly spaced points along the vertical axis. As you move up from the center (Saturation = 100%), saturation values decrease progressively as distance from the center increases. Exactly as expected.

TK Basic V6 panel

But look what happens as colors get darker. Saturation values, again extracted from the Color Picker, do NOT decrease when moving downward from the center. As colors get more black and contain less color, saturation values don’t change. Saturation remains at 100% even though the amount of color present is gradually decreasing. Even the very bottom pixel of the Granger Chart still has a saturation value of 98% according to the Adobe Color Picker. Strange, huh? Why does saturation remain unchanged as color intensity decreases and black increases? And why are the dark colors different than the light colors?

The actual saturation mask produced using the HSB/HSL filter (the “Green” channel after converting to HSL) matches values from the Color Picker. It is shown below. As a quick review, a saturation mask shows white or light gray in saturated colors and shows black or dark gray in unsaturated colors. For light colors, the HSB/HSL-produced saturation mask shows a smooth decrease in saturation, fading from white to black when moving from the center towards the top edge. This is exactly as expected. The central intensely colored pixels are highly saturated and show as white in the saturation mask. When moving towards the top, saturation decreases, so the mask turns gradually darker gray until it is entirely black at the top border, which is white in the image (and therefore 0% saturated).

TK Basic V6 panel

But look what happens with this HSL mask in the dark colors. The dark colors in the image remain pure white in the mask (indicating very high saturation) even though they contain less and less color when moving from the center towards the bottom. Yes, this matches the saturation values derived from the Color Picker, but it ignores the obvious fact that color saturation actually decreases gradually as you move lower from the center of the Granger Chart. There is no corresponding smooth transition in the saturation mask of the dark colors like in the light colors as would be expected.

This is the asymmetry problem that comes from using the HSB/HSL filter to produce saturation masks. Light colors show appropriate saturation and feathering in the HSB/HSL saturation mask, but dark colors show exaggerated saturation and no feathering at all.

The important thing to take away in all this is that a saturation masks created using the HSB/HSL filter significantly (and sometimes grossly) overstate saturation in dark colors of the image. Dark colors end up being mapped as more saturated than they really are. This is also demonstrated in the image below. Its HSB/HSL saturation mask is shown beside it. Notice how the letters and numbers, even though they are nearly black, are showing as a very light gray in the saturation mask created using the HSB/HSL filter. This indicates they contain highly saturated colors. But this is obviously wrong. No way does a color this dark have the degree of color saturation indicated by the mask. Black is 100% UNsaturated, and any colors approaching black should be very dark in a mask that accurately maps color saturation. But in this mask, the characters in “OPEN” and “7 TO 7” are very light. Based on these tones in the mask, their color saturation in the image should exceed that of the deep blue sky (which is a darker gray) and approach that of the reds and yellows in “GRILL” (which are also very light gray). Even worse, the black word “GEARHART” is mapped in the mask as being more saturated than the magenta background behind the hamburger bun. These characters are clearly less saturated than this. So this isn’t just a theoretical concern that happens in a mathematical image like the Granger Chart. The same problem of the mask showing over-saturation of dark colors is also quite obvious and quite extreme in an actual image.

TK Basic V6 panel

NOTES:

  1. The question can fairly be asked as to why these dark colors aren’t actually pure white in this saturation mask of the image as the dark colors are in the Granger Chart? I’m not entirely sure, but I think this probably relates to the way the Granger Chart is created. It’s made from two gradients: one of completely saturated colors and the other of black-to-white tones. I have a feeling that the colors it produces are only a subset of all colors (even though it creates what appears to be a spectrum of all color) and it’s these specific dark colors that get mapped to 100% saturation by Adobe’s Color Picker. Although, it may also be related to how Photoshop converts from RGB to HSL. Or it could be some other reason entirely. The Granger Chart happened to be what I was using when experimenting with saturation masks, and was what tipped me off to the HSB/HSL problem of dark colors appearing more saturated than they really are. But the over-saturation of dark colors has been apparent in all “real” photos that I’ve made saturation masks for using the HSB/HSL filter. The over-saturation of dark colors is seldom 100%, like with the Granger Chart, but it is always very obvious once you’re aware of it and start comparing the saturation of dark colors with other, truly more saturated colors in the image.
  2. It is also worth noting that there is still some self-feathering of the of the over-saturation in HSB/HSL-produced saturation masks in “real” images. There is no abrupt cutoff like with the Granger Chart HSB/HSL saturation mask. So using these HSB/HSL masks would still lead to a smooth blending of whatever is adjusted through such a mask. However, visually evaluating these HSB/HSL-created masks to decide where saturation is truly present in the image is nearly impossible since the dark colors end up being so light in the mask that they frequently outshine actual saturated colors. The bottom line is that any adjustment through such a mask intended to affect actual saturated colors in the image disproportionately affect darker colors in the image instead.

SAT mask menuWith the problem described, the question becomes how to make a more accurate saturation mask, one that treats light and dark colors equally so that the saturation in darker colors gradually tapers off as saturated colors are replaced with unsaturated black. What that mask looks like for the Granger Chart is shown below and was generated using the “SAT” mask option in the TK RapidMask2 panel. It shows perfect saturation feathering in both light and dark tones. This is easily achieved when using a better method than HSB/HSL to generate TRUE saturation masks.

TK Basic V6 panel

Below is the test image along with the more accurate saturation mask generated from the RapidMask2 panel. The most colorful areas are now the brightest shades of gray in the mask and elements with little or no color (the words “OPEN”, “7 to 7”, and “GEAHART”) are very dark gray. This is exactly the way it should be in a pixel-based mask that accurately maps color saturation.

TK Basic V6 panel

I’ve been using this more advanced method for making saturation (and vibrance) masks in my panels and developing workflow for close to a decade and wouldn’t return to using the old HSB/HSL filter at this point even though Adobe once again makes it available. I’ll explain how to create these TRUE saturation masks in an upcoming blog.

SUMMARY: Saturation masks produced using Photoshop’s HSB/HSL filter display asymmetrical saturation when comparing light and dark colors. Light colors show a perfectly feathered saturation transition as colors get lighter and less saturated while dark colors get mapped as being more saturated than their color would suggest. A better method for making saturation masks would take into account pixel brightness as well as saturation.

FINAL NOTE: I’m not an expert in color models and do not know why the HSL/HSB filter maps saturation the way it does or why the Saturation values in the Color Picker remain at 100% for dark colors. I just know that pixel-based masks need to accurately display the pixel-based values I’m looking to adjust if they are to be useful. That way I can properly evaluate the mask and modify it, if need be, to match my image. In the case of saturation masks, the HSB/HSL filter is definitely substandard for creating the type of masks I want to use.

New Complete Workflow video series by Sean Bagshaw: Lake Bled

May 3, 2018

I’m very pleased to let folks know that Sean Bagshaw has released his third Complete Workflow video series. This one covers his “Lake Bled” image from Slovenia from start-to-finish and uses the new TKActions V6 panel. Exposure strategy, development planning, RAW file adjustments, mask making, exposure blending, fine-tuning, and creative development are all covered. Sean makes some intricate masks for this workflow that are an important part of the blending and development process. The last two chapters are my favorites since they do a nice job highlighting the creative control possible with the V6 panel. But there’s a lot to watch and learn in all the chapters, and Sean uses the V6 panel nearly constantly as he works.

Lake Bled photo

Sean has been regularly recording Complete Workflow videos for each new version of the TKActions panel, and starting now they are all bundled into one very economically priced product. The older series feature older versions of the panel (Secret Beach–V4 panel and Northland–V5/V6 panel) , but they still demonstrate the huge variety of different techniques Sean employs to create his dramatic images. If you don’t have the previous videos, the new three-volume set is essentially a guidebook to creative development.

Sean is one of the leading instructions in landscape photography today, and I’m happy to be working with him and being able to offer his high-quality instructional videos on my website. If you’re looking for photographic inspiration, these Complete Workflow vids offer hours of ideas both for working in the field and then in Lightroom and Photoshop. The sample videos below are from the Lake Bled series.

The new 3-series bundle of Complete Workflow videos (Secret Beach, Northland, and Lake Bled) is available on the Panels & Videos page for $45. Blog readers can also use the following code for a 10% discount on this product: CWFLB10

NOTE: I’ve contacted previous customers with private update information for receiving the new Lake Bled video series at a special price. If you’re a previous customer and haven’t received the email, please contact me and I’ll forward the information. Also, there was initially some server issues downloading the new series, but these have been resolved. If you purchased the new series but are still having download issues, definitely contact me and we’ll get it fixed.



TKActions Quick Tip: Exposure blending

April 12, 2018

Sean Bagshaw is heading out into the field soon, but he managed to squeeze in one more video Quick Tip before leaving. This one covers the popular subject of exposure blending. Because luminosity masks target specific tones in an image, they’re a natural for making masks that blend multiple exposures where the dynamic range of the scene exceeds that of the camera sensor. Sean’s approach to exposure blending has been to focus on the transition zone between light and dark areas of the image to make the blend look natural. Luminosity masks can help significantly with this process since they create natural transitions based on pixel brightness. The steps Sean uses are listed below.

  1. Open the RAW files as smart objects in Photoshop.
  2. Stack the images into a single document with the dark exposure on top.
  3. Make the dark exposure layer active, but turn OFF its visibility.
  4. Click the “Layer Mask” checkbox on the RapidMask2 module to enter Layer Mask Mode. This mode automatically applies the mask generated as a layer mask on the active layer.
  5. Click the “Composite” source button to apply a “Lights-1” mask as a layer mask to the active layer (the dark exposure). This starts the blending process.
  6. Turn the visibility of the dark exposure layer back ON to evaluate the blend.
  7. Modify the layer mask to create the proper transition zone. This might involve trying a different mask, using the MODIFY buttons to modify the current mask, or painting on the layer mask with black or white paint (try setting the blend mode of the paintbrush to “Overlay”).
  8. If needed, double-click the smart objects to reopen them in Adobe Camera Raw to make additional adjustments to brightness, contrast, white balance, etc.

It’s actually pretty easy watching Sean do it. In the 15 minute video he demonstrates the process, with small variations, using three different images.

Quick Tip: Exposure blending
Quick Tip: Favorite new V6 features
Be sure to subscribe to Sean’s YouTube channel for more tips on photography and post-processing.

TK Actions Quick Tip

March 30, 2018

As many of you know, I’ve been collaborating with Sean Bagshaw for many years on luminosity masks and Photoshop extension panels. He not only feeds me ideas for improved ways to use pixel-based masks, but his videos have also been instrumental in explaining these techniques to the photo community.

Now that TKActions V6 is complete, Sean is planning to restart his Quick Tip series on how to use the new panel. This will provide a great opportunity to watch an expert using the V6 panel, to get a more in depth look at its many functions, and to pick up some creative ideas for developing images in Photoshop.

I’ll be featuring Sean’s videos on this blog and providing some commentary on the techniques, but you might also want to subscribe to Sean’s YouTube channel. That way you can get notified of the other videos that he regularly publishes. He’s got a really nice teaching style that provides a lot of information and is also easy to follow.

His first V6 panel Quick Tip is below and looks at his favorite new features. It’s less than 5 minutes long and gives you an idea of what’s coming.

TKActions V6: New modules

March 21, 2018

“Combo” and “Batch” are the newest modules to be released in the latest update of the TKActions V6 panel. The RapidMask2 V6 module was released in October 2017. With the release of these two new modules, the V6 panel is now complete.

NOTE: Previous V5 and V5/V6 customers have already been sent information for a free download of these updated V6 modules. Check your spam/junk if you missed it. Update information was sent on February 26 and resent on March 3. If you’ve not purchased the panel yet, for the next 3 weeks you can use the following code on the Panels & Videos page for a 25% discount on all items: V625off

The new Combo module comes in two versions: Combo and ComboX (also designated Cx). The different arrangements have identical functions, but they make it possible to create two very different workspaces to utilize the V6 panel. This is explained in the “Custom V6 Panel Workspace” video at the end of this blog.

TKAction V6 panel

The Combo module combines the Control and Action modules of the V5 panel into one. This continues the evolution away from the button-crazy, multi-mega-panel design trend to a more compact, efficient, and logical workspace that started with RapidMask2. Most users will now need just two modules in order to access V6 functions: the RapidMask2 module makes all the different luminosity masks and Combo runs Photoshop. The V6 modules use smart menus to replace confusing tabs and even entire panels. A good example is the “TK ▶” button. It opens a menu that contains all the actions of the V5 Actions module plus several new ones (image below). While these actions can be extremely useful when developing images, it’s not necessary to have them in a separate panel given that they are used one at a time and generally only occasionally during processing. The smart menus in the Combo and RapidMask2 modules track what’s happening and automatically close once they’ve served their purpose.

TKActiosn actions menu

Below is a short list of the features of the new Combo/Cx modules.

  • Compact design−Combines the all features, functions, and actions of the V5 Control and Actions modules into one.
  • Run Photoshop from the module−Many common Photoshop functions, keyboard shortcuts, and menu items can be run with a single button click from the module.
  • Muted color interface separates buttons into logical groups in order to quickly find the correct Photoshop function. (Color is adjustable in the Settings window.)
  • Multi-function buttons−Several buttons have dual functions that are graphically displayed on the button itself.
  • Use the “TK ▶” button to access the creative Photoshop actions menu−Includes new actions for Smart Orton and Neutralize Cast 2 for creative development, and Stack, Align, and Focus Blend for blending multiple exposures.
  • Integrated web-sharpening−Sharpen images for the web to any dimension, convert to sRGB, and run post-sharpening actions with one click directly from the module.
  • Expanded user actions−Ten programmable actions, accessed via the “User ▶” button, allow users to run their own actions directly from the panel.

This update also includes some additional enhancements to the RapidMask2 module that was released in October 2017.

  • Advanced Mask Calculator−Any mask created using the panel can be added, subtracted, and intersected with any other mask. This makes it possible to combine luminosity, color, saturation, modified, and even user-created masks in any manner desired. There is also an Advanced Mask Calculator in Layer Mask Mode so users can see the results reflected immediately in the image itself.
  • Enhanced “Pick” button−The Zone mask that is picked is highlighted directly on the panel. This makes it easy to experiment with adjacent or nearby zone masks to see if one of them might work a bit better.
  • Properties panel toggle−Creating an adjustment layer automatically opens the Properties panel so that the desired adjustment can quickly be made. This feature is also active when using the Combo panel to create adjustment layers.

The Batch module is also part of this release. It resizes and sharpens entire folders of images for web presentation. It may not be used frequently, but can be huge time-saver when there are lots of images to sharpen.

The videos below provide a brief overview of the V6 panel. Additional information can be found on my website. The comprehensive instructions PDF for the V6 panel can be downloaded here. To purchase the V6 panel plus other panels and videos, please visit the Panels & Videos page. Don’t forget to use the V625off discount code. It also works on Sean Bagshaw’s videos listed on that page.

Please contact me if you have any questions.




“Briscoe Light”

January 6, 2018

Sean Bagshaw has a great new video on creating dappled light and light rays using a technique he learned from Chris Briscoe.

The user gets to manually create the target that determines where the light is applied in the image. It looks to be dramatic yet subtle and also quite natural when done right. Definitely worth investigating if you’re into creatively modifying images in Photoshop.

Be sure to subscribe to Sean’s YouTube channel to get his latest tips, tutorials, and updates.

Brightness adjustments using Selective Color and luminosity masks

January 1, 2018

I recently started experimenting with Selective Color adjustment layers. Normally I rely on Curves and Levels for brightness and contrast adjustments, but in reading about and experimenting with Selective Color, it definitely has some advantages, especially when adjusting the light and dark tones in combination with luminosity masks.

The image I’ll be working with is shown below. After looking at a print for a couple of days, I realized it could use more drama, especially in the sky−darker clouds, a bit more contrast, and perhaps additional texture. (You can roll the mouse over the image to see the final result. It may take a few seconds for the second image to load. Rollovers probably will not work in the email feed, so please visit the blog if you want to see rollover images.)

base image

The Selective Color Properties panel has a drop-down menu of colors. The panel’s sliders are labeled with CYMK colors, but they actually allow hue, saturation, and brightness to be independently adjusted for any item chosen from the list once you understand how this panel works. For this tutorial, the “Whites” and the “Blacks” will be of primary interest. Using the “Whites” and “Blacks” to adjust image brightness (and to some degree contrast) has the advantage of avoiding the saturation and color shifts associated with using Curves and Levels for this purpose. With Curves and Levels adjustments, saturation and color changes become mixed in with brightness/contrast changes, and it’s hard to separate them out.

The best way to see this is with a strong “S-Curve” equivalent adjustment using different types of adjustment layers. The S-Curve adjustment increases contrast−the lights get lighter and the darks get darker.

In the Selective Color adjustment, the “Whites” correspond to the light values in the image and “Blacks” correspond to dark values. In order to create an “S-Curve” equivalent, the “Whites” from the drop-down menue need to be less black and the “Blacks” need to be more black. The screen shots below show the two Selective Color adjustments necessary to produce a strong “S-Curve” equivalent adjustment.

selective color adjustments

A similar adjustment for a Curves adjustment layer is shown below. Lights get lighter and darks get darker. (This curve shape is where the name “S-Curve” comes from.)

selective color adjustments

The results from these two similar adjustments, however, are definitely NOT similar. Below is the result from the Selective Color adjustment. Rolling the mouse over the image shows the result of the Curves adjustment. What’s immediately obvious is that the Curves adjustment has undergone a strong saturation shift compared to the Selective Color adjustment. All colors are more intense as a result of the S-Curve on a Curves adjustment layer. This does NOT happen in the Selective Color adjustment because the “Neutrals” in the drop-down menu, which basically correspond to the midtones in the image, have NOT been adjusted. Only the “Whites” and the “Blacks” were adjusted. It’s the midtone values that cause the color and saturation shifts in Curves and Levels adjustments. With Selective Color, it’s possible to leave these midtones (“Neutrals”) untouched, and the result is increased contrast without significant color and saturation changes. (NOTE: As an experiment, select the “Neutrals” and then move the “Black” slider to the right to add more black. There will be a sudden and pronounced shift in color saturation. This clearly demonstrates how the midtones are the source of the color and saturation shifts seen with Curves and Levels, where the midtones cannot be so easily excluded.)

With Curves and Levels adjustment layers, it’s common practice to change the blending mode to Luminosity to counteract the saturation shift, and the image below, which shows the Curves adjustment layer set to Luminosity blend mode, shows that this does indeed help. However, there are still color shifts, and the rollover (which shows the Selective Color adjustment) shows that they are still present. It’s most obvious in the blues of the lower clouds, but also somewhat visible in the reds and yellows. So when it comes to avoiding color and saturation shifts, Selective Color has an advantage even after changing the blending mode of the Curves adjustment to Luminosity.

For the adjustment to this image, I ended up using only the full-on “Blacks” Selective Color adjustment that darkened the “Blacks” as much as possible. The light tones in the image really didn’t need any lightening so the “Whites” were not changed. The result of this initial adjustment is shown below.

selective color adjustments

This adjustment is definitely too aggressive for my taste, but that’s intentional. It provides a good starting point for using luminosity masks. A luminosity mask can be used to filter this adjustment only to those tones that really need it. In doing so, much of the exaggerated adjustment will be concealed by the mask. The end result will be a more balanced adjustment that blends in perfectly to the rest of the image.

In this case, I experimented with Darks, Midtones, and Zone masks and found that a Zone 4 mask added as a layer mask did a nice job of creating the desired effect. The result after adding the layer mask is shown below. The rollover shows the adjustment without the luminosity mask in order to see how seamlessly the mask blended the adjustment into the image.

The ease at which a preset luminosity mask finished this adjustment points out another possible advantage of using the Selective Color adjustment. And that is that it works well to create an initial adjustment to a broad, but limited, range of tones (“Whites” or “Blacks”), which can then be quickly and accurately refined with a luminosity mask. It’s almost like having a targeted double-masking technique where a strong targeted adjustment is first applied, and this can then be fine-tuned and focused using the narrower tonal range of a luminosity mask.

The video below shows the entire process for this adjustment that accomplishes the goal of adding drama in the sky. It uses the RapidMask2 panel’s Layer Mask Mode to quickly find the right luminosity mask for the adjustment. There is also a similar adjustment to a second image included in the video that uses the “Whites” instead of the “Blacks.” If you’d like to practice along with the video, a smaller jpg version of the unadjusted image is available here. (The download image will probably open in a browser window. Right-click on it and choose an option to save it on your computer, and then open it in Photoshop.)

SUMMARY−Adjustments to brightness (and to some degree to contrast) using a Selective Color adjustment layer helps avoid the saturation and color shifts associated with Curves and Levels. Additionally, Selective Color adjustments allow a two-step adjustment process where the initial, somewhat extreme adjustment can be easily modified by applying a more targeted luminosity mask to the adjustment layer to better control which tones in the image are affected.

FINAL NOTE: Every image is different and there’s likely no single workflow with Selective Color and luminosity masks that will work the same repeatedly. I’m finding that using Selective Color to adjust the “Whites” and “Blacks” provides expected and desirable results once I find the correct luminosity mask as demonstrated in the video. It’s always possible to return to the Properties panel to tweak to the initial Selective Color adjustment if necessary.

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