In Part 1 of this post I covered image sharpening in Adobe Photoshop. Today, more and more photographers are migrating the bulk of their image-editing work to Lightroom, thanks to a more streamlined interface, and features that are tuned to photographers, not general graphics.
While it might seem that sharpening would be the same in both Lightroom and Photoshop, there are some significant differences between the two. Yet the goal is the same – make your image as sharp as you want without showing visible signs of the sharpening process.
Sharpening in Lightroom is a two-stage process. Because you’re not dealing with image sizing until you output the image, you can’t wait until this point to go to a Smart Sharpen or Unsharp Mask type of dialog. In Lightroom, you do your sharpening in the Develop module, going for optimal image sharpness. Then you can do a final sharpening on output (this last step is optional though).
To get started, select the image you’re working with and do all of your adjustments for color balance, tone curves, and saturation. In Lightroom, the initial sharpening is done through the Detail panel in the Develop module (Figure 1). Amount, Radius, and Detail are essentially the same as the Amount Radius and Threshold controls in the Unsharp Mask dialog of Photoshop.
A new slider is available in Lightroom though, Masking. Like the name implies, Masking essentially hides the sharpening effect in areas of smoother tones. Rather than describe how these work, let’s take a look at the controls in action. Lightroom makes it easy to see what your adjustments are doing by holding down the Alt key while making adjustments
NOTE: In order to see what changes the Details panel adjustments are making, you need to be viewing your image at least at 1:1, or 100%.
With the Amount slider, you’re controlling how strong the adjustment is going to be. Hold down the Alt key while moving the slider. Your image will switch to grayscale. By hiding the color information, it makes it easier to see how the adjustments are affecting your image (Figure 2).
Your goal here is to enhance the overall sharpness of your image without creating obvious artifacts, particularly on high-contrast edges. Once you’ve found a starting point that feels right, move on to the Radius slider (Figure 3).
Radius controls how wide the edge contrast enhancement extends, with higher numbers making for a wide adjustment. As you drag the slider while holding down the Alt key, you’ll see the image shift to wider, bolder lines. I tend to keep this setting as low as possible. With finely detailed images, you can use a very narrow radius to maintain the natural look of your subject.
Detail, like Threshold in Photoshop, controls how much difference there needs to be in neighboring pixels before they’re considered an edge that should be enhanced. With the Alt key held down, changes to this control will look similar to the Radius control (Figure 4). Your goal here is to keep the smoother areas of your image looking smooth to avoid an artificial look.
The final control is what sets Lightroom apart when it comes to image editing. With the Masking slider, you are essentially painting a mask on your image, and like Photoshop, areas that are black have the effect hidden, while white areas show the adjustment at full strength. Areas of gray show varying degrees of the adjustment based on the shade of gray (Figure 5).
As I mentioned earlier, these adjustments are done prior to image sizing and choosing your output type, which seems contrary to normal methods. Lightroom does a very good job of tuning these adjustments to the output size though, making this work well. There is a further step you can take with specific output sharpening though. These options are found in the Print module and Export dialog. They’re presets that can’t be altered, and they make subtle changes to your image based on paper type (Figure 6), with three different levels of sharpening. I find Standard to work well for most images, but I’ll select Low for portraits. I’ve never found an image that I would use the High setting on though.
In Export, you can choose between Screen or Print (useful for those times you’re sending your work out for print). Once again, Standard and Low work well, but I avoid High (Figure 7).
More on Sharpening
If you really want to know the ins and outs of sharpening, Real World Camera Raw by Bruce Fraser is a great resource. It only covers Photoshop, but many of the techniques apply regardless of what application you use, and Bruce does a great job of explaining more advanced techniques like luminance sharpening.
One of the most common questions I get in workshops and from readers of my books or articles is how to best sharpen a digital image. A properly sharpened image can make a big difference in the perceived quality of a photo, whether it is viewed online or in print. Conversely, nothing screams digital image more than an over-sharpened image.
Sharpening Defined. First, the basics. Sharpening really isn’t sharpening or changing the focus of your image. If you start off with a soft image, no amount of sharpening is going to correct that problem. What is happening when you sharpen is that the contrast of the edges in your image is being enhanced. Figure 1 shows the Unsharp Mask dialog in Photoshop. This is where most people are doing their sharpening work. It might seem easy enough, there are only three adjustment controls to work with.
The Amount slider controls how much the edges will be enhanced. This is pretty straightforward.
The Radius slider determines how wide the edge enhancement effect will be. This is often where people go overboard.
The third control, Threshold, is what sets the boundaries for Photoshop to determine whether a pixel is an edge or not. The higher the number is here, the greater the difference in values needs to be between pixels before they’re considered an edge.
A natural tendency for people new to sharpening is to use settings that are too high, particularly for the Radius. This will lead to a halo effect around the obvious edges of your image like those shown in Figure 2.
A better method of sharpening using the standard tools in Photoshop is the Smart Sharpen option (Filter > Sharpen > Smart Sharpen).
This has a couple of benefits. First, the dialog is resizable, enabling you to see more of your image to get a better idea of the effects your adjustments are having. Secondly, the sharpening algorithms used in Smart Sharpen do a better job of edge-contrast enhancement.
An even better approach is to use one of the third-party sharpening options such as Photokit Sharpener, or Nik Sharpener Pro. Both of these will help you to select the optimum settings for print output or screen display. If you are printing the image, you can optimize sharpening based on the type of paper you plan to use.
When to Sharpen. Sharpening should be done as the last step in your workflow. Do it after all of your other edits have been to the image—just before you save the file for screen display or printing. Because sharpening is a destructive process (you’re changing pixels on the image), you want to do it with the final pixels you’ll be outputting as a print or screen display. If you sharpen prior to sizing for output, you’re liable to end up with an image that has visible artifacting from the sharpening process, or you’ll need to sharpen a second time to fine tune the output – creating more opportunities for image degradation.
If you’re using Adobe Lightroom, this all becomes a little fuzzy because the entire workflow is non-destructive and there is no real concept of resizing until the image is exported or printed. Lightroom uses sharpening techniques based on Photokit sharpener and does a really nice job. There are additional output sharpening options in the Export dialog and in the Print module. In an upcoming post, I’ll cover sharpening from Lightroom in detail.