I’ve lately been talking about photo post-processing workflows on various podcasts, Google+ hangouts, classes and workshops, which has generated a lot of questions and requests for more info. It’s my workflow du jour because I’ve never had a single workflow that’s lasted for more than a few weeks. By the time you read this, it will already be out of date. For that matter, I don’t really have a formal workflow since every image is different. But I’ve developed a default sequence as the starting point for most of the images I shoot. At least for this week.

I spent some time debating whether I would publish this blog post or not. I’m actually a bit nervous about telling everyone about some parts of the workflow — not because I want to keep them secret, but because I fear you will go directly to the shortcuts I recommend without taking the time to understand the concepts behind them. You can get pretty good results without studying the underlying theories, but you’ll be shortchanging yourself. Obviously, I’ve decided to go ahead with this post in the hope the tools not only simplify your post processing but also encourage you to dig deeper into how they work and how they can be further manipulated.

I should also point out that there’s nothing of my own creation in this workflow. Everything I’m using I’ve learned from others who know a lot more about post processing than I do. Towards the end of this article I’ve linked to the original work of my personal workflow gurus so you can learn directly from the sources.

What Are the Prerequisites?

Although much of my workflow uses automated Photoshop actions, some of the steps must be done manually. This is not for Photoshop newbies. Before utilizing any of the tips and tools in this article, you should first learn the following aspects of Photoshop:

• selections
• layers and layer masks
• channels
• curves
• the Image->Apply Image… menu feature

What Are the Shortcuts?

My workflow du jour uses two Photoshop plugins. The first is Dan Margulis’ free Picture Postcard Workflow Panel shown below on the left. (The name is cute but misleading. It’s not just for a picture-postcard look.) The panel automates many of the steps in Dan’s Picture Postcard Workflow, which if done by hand not only make for a complex process but can’t be performed by mere mortals without pages of notes. You can really get yourself into trouble with this tool, but you can also achieve amazing results in no time at all once you get the hang of it.

The second Photoshop plugin, shown on the right, is the Channels Power Tool (€20). This is a tremendous timesaver for identifying and swapping channels and applying them as layers and masks such as in Lee Varis’ 10-Channel Workflow.

What About Lab Color?

Much of my current workflow is based on the Lab colorspace, which I’ve been using on and off for about 2.5 years. I first wrote about Lab color in 2010, specifically in conjunction with HDR. I stopped using Lab color for a while because I didn’t fully understand it. Although I’m still learning and experimenting, I now believe I’ve achieved a deeper comprehension of the true potential of working in this colorspace.

You’re probably familiar with the RGB colorspaces in which there are three channels: red, green and blue. Your digital camera records images in RGB and your browser displays images using RGB. When an image is printed using offset press inks, it’s converted to the CMYK colorspace with cyan, magenta, yellow and black channels.

Consider how you change the brightness or luminosity of an image in RGB or CMYK. In RGB you increase the levels of all three channels. 100% red, green and blue gives you white. 0% results in black. In CMYK, you reduce the amount of ink in all channels in order to get to white, the color of the underlying paper. But the problem with both RGB and CMYK is that there’s no way to change the luminosity of an image without also changing the hue and/or saturation of the colors.

When is Lab Better Than RGB or CMYK?

Lab is just another colorspace like RGB and CMYK, but it separates luminosity from color. There are three channels: The “L” channel controls luminosity but has nothing to do with color. Conversely, the “a” and “b” channels control only color and don’t affect brightness. The range or gamut of the Lab colorspace is huge. Not only can it represent every color of RGB and CMYK, it can also represent colors that are beyond reality. (Try to imagine a yellow that is simultaneously very saturated and as dark as pure black.) Lab is also an extremely accurate and standardized colorspace. Whereas we all need to calibrate our RGB monitors and adjust for our printers, papers and inks, the colors in Lab are precise. For example, when an automobile body shop wants to exactly match the color of your car’s paint, it uses the Lab color specified by the car’s manufacturer.

Unlike RGB and CMYK, the Lab colorspace is designed to approximate human vision, which has a powerful ability to segregate colors. For instance, we can perceive variations in green leaves where there may be very little luminosity difference. The channel structure of Lab allows us to manage both luminosity contrast, with which we’re all familiar, and (separately!) color contrast. The latter concept may be new to you. In RGB we have little opportunity to adjust the contrast of various colors, but in Lab color mode we can do just that. Photographs can often be improved by increasing the color contrast in order to enhance those differences.

Lab’s a and b channels specify opposing-color axes that you can visualize as a color wheel. The a channel specifies the green/magenta axis while the b channel represents the blue/yellow axis. (The image below is a bit misleading because it doesn’t show the variations from the center to the edges. Unlike RGB and CMYK, these are variations of pure saturation, not combined with luminosity.)

When you add a curves adjustment layer in Lab color you can do things you’d never be able to accomplish in RGB. For example, you can warm up the saturated blue portions of your image without affecting the other less-intense blue areas, and do so without ever creating a layer mask. You can increase the contrast in the greens without shifting the overall cast of the image. It takes a while, but once you get the hang of it, working in the Lab colorspace is extraordinarily powerful.

Why Should I Use Lab Color in My Workflow?

Let’s start with an example. Below are three versions of a single image.

The above image is pretty much straight out of the camera. Note a few problems:

• There’s a blue cast in the shadows.
• There’s relatively little contrast either in luminosity or color.
• The lack of contrast makes the image look flat and lacking in depth and detail.

The second version above is typical of what you can achieve with basic Photoshop skills. The color and contrast are somewhat better, but there’s still a blue cast to the shadows.

The final image above is the result of spending no more than five minutes tweaking in the Lab color space. I was able to remove the blue cast from the shadows as well as increase both the luminance and color contrasts.

Did I correct this image using only plugins and clicking on buttons? No. In this case I had to resort to creating curves in Lab color mode and to changing the opacity of various layers. Although I made all the changes to this image in less than five minutes, I did rely on some of these more fundamental and manual operations. I mention this as an example of why the shortcuts alone are often insufficient and why you need to learn the underlying concepts.

You can download Dan’s PPW Panel and start using it immediately, but as I wrote at the beginning of this article, you’ll be far more effective if you invest the time to understand how the various actions work and Lab color in particular. The PPW Panel includes extensive Help files, but they’re not the best place to start. The Help file for Dan’s 2012 Sharpen action alone is 23 pages long.

Unfortunately, there’s a huge gap and a steep learning curve separating the use of the shortcuts and truly understanding how they work. Here are my recommendations (in order) of the resources you might use to learn about channels, Lab color and the rest of these workflow concepts:

• Mark Lindsay teaches and writes about Lab color and related techniques. Mark has posted some of the best introductory articles, but he hasn’t yet gone very deep into his workflow. His articles include:
  • Why Lab?
  • Starting with the A and the B of it
  • The Classic Move — This is the very first thing you should learn how to do in Lab color mode.
  • Multiply and Layer Mask Technique for Lab Color Mode — Absolutely the second manual Lab mode technique you should learn even if you eventually decide to use Dan’s PPW panel instead. (When you figure out why blurring a layer mask sharpens your image, please explain it to the rest of us!)
• Check out Lee Varis’  Professional Photshop Toolkit. In addition to Dan’s PPW Panel, Lee’s toolkit includes:
  • Free videos covering Lee’s 10-Channel Workflow and many other topics. At this point you’ll be into swapping channels, using channels for masks and blending modes. You may never make another selection by hand again.
  • You’ll want to get the Channels Power Tool (€20). This is almost mandatory for Lee’s 10-Channel Workflow.
  • The False Profile Panel (free) is another plugin you’ll occasionally find useful once you get this far.
• Download, install and use the latest Picture Postcard Workflow Panel for Photoshop. This automates most of what you’ve learned so far. Click on the Help button and read all of the associated PDF files. You’ll be busy.
• Take a break from Dan’s extensive Help files, sit back and watch his videos on Kelby Training. If you’re not already a member, I suggest you sign up for one month (US$24.95) during which you can watch all these courses. It will be some of the best $$ you spend on photography.
  • Start with Introduction to Photoshop Lab Color.
  • Next, watch The Lab Frontier.
  • Work with what you’ve learned from Dan and try the techniques as explained by Mark Lindsay above.
  • Come back to Kelby and watch the courses on the Picture Postcard Workflow Part 1, Part 2, and Part 3. These explain the manual processes of the PPW but pre-date the release of the PPW Panel.
• You now qualify as an Lab color geek. Go directly to Dan Margulis’ Lab color bible, Photoshop LAB Color: The Canyon Conundrum and Other Adventures in the Most Powerful Colorspace. This will keep you really busy for a very long time!
• For extra credit, now that you know all about channels, take your knowledge back to RGB and explore Tony Kuyper’s treatise on Luminosity Masks. (Note that the first steps in Margulis’ PPW are done in RGB, so Tony’s concepts work well here.)

You’ve got to be kidding! It will take you months to get through the resources I’ve outlined above. And then you’ll want to go over them again to truly nail down the concepts. In any case, this is the point to which my knowledge of Lab color has progressed as of late November 2012. I’m in the process of my second pass through everything. It’s geeky, but it works for me. I hope it works for you as well.

As you have questions or learn of additional resources, please leave a comment and I’ll use it to update this page.

Updates

• 11/25/12: Scott Loftesness and I have been collaborating together on this Lab-based workflow stuff for the past few weeks. Each of us has tried one technique or another, then to have the other adopt and improve on it. It’s been a valuable, mostly remote collaboration. Because these techniques can be so confusing at first and the learning curve so steep, I recommend you also find someone with whom you can study/learn with. More than once, Scott and I have needed the other to either explain a technique or at least remind the other what it was we’ve already learned. Scott has just posted an example of his own workflow du jour and it contains some very specific steps. I’m still digesting them myself and will see if I can (a) understand them, and (b) merge them into my own processes.
• 11/25/12: Since posting the original article only two days ago, I’ve added the free Advanced Local Contrast Enhancer (ALCE) Photoshop plugin by Davide Barranca to my workflow. It’s like Lightroom’s Clarity feature, but on steroids. Make sure to check out the excellent video tutorials by Marco Olivotto.