PUTTING A FINE EDGE ON YOUR SHARPENING

Sharpening is an essential part of editing any digital image. My TLR Sharpening Toolkit provides a set of Photoshop actions for sharpening images. There are nearly 20 actions inside the action set, enabling you to sharpen your images like a pro.

The TLR Sharpening Toolkit is a sophisticated tool. There are lots of options. You can use it to sharpen in three passes, the current recommendation of most pros, two passes, or even a single pass. This learning gallery walks you through the major features.

Feel free to download my tutorial on sharpening, too. It describes the philosophy underlying the action set.

 

Getting Started

I strongly recommend that you use layers for sharpening. If you are short of RAM or your processor is slow, sharpening on layers might not be practical. But, if you do have plenty of RAM, sufficient harddrive space for larger files, and sufficient processor speed, you will benefit from using layers.

Layers allow you to work nondestructively with your image. You can change your mind later and delete the sharpening and substitute another. My preference is to create the new layer with 65% opacity. That way, I can dial in or dial out some of the sharpening effect.

If you want to use Highpass Filter sharpening, you have no choice. You must use a layer. The technique requires that the sharpened layer use a Soft Light, Overlay, or Hard Light blend mode.

If you do not want to use layers, you can still use USM and do it nondestructively. Make a duplicate of the image and flatten it. Then sharpen the flattened duplicate. Your previous edits will still be intact in the original image.

The first step, then, before any sharpening pass is to prepare the file for sharpening:

(1) Create a new blank layer and move it to the top of the Layers palette. Rename it, if you like. Then press alt-ctrl-shift + e on a PC (option-cmd-shift + e on a Mac) and all of the visible layers will be merged and copied into the new layer. Set the opacity to 65%.

-OR-

(2) Duplicate the image. Flatten it. Close the original image and work on the duplicate.

 

Capture Sharpening

The goal of capture sharpening is to restore the detail that is lost during digital capture and nothing more. You want to increase the image detail without emphasizing noise. Capture sharpening requires a gentle touch. If you introduce sharpening artifacts early in your workflow, they will almost certanly compound as you edit the image. Save the aggressive sharpening for output sharpening toward the end of your workflow.

A frequently asked question is, "Should I use the camera sharpening settings? How about the sharpening settings for my RAWconverter?"

My suggestion is that you use neither. The advantage to sharpening in-camera or during RAW conversion is ease and speed. You sacrifice a lot, though. If you do use either, that's your capture sharpening pass. So skip on to creative sharpening or output sharpening.

Sharpening during RAW conversion is like sharpening on the background layer. It is better to work nondestructively with your image. The sharpening method in most RAW converters is a black box. Sometimes, all you have is a few presets. You will have much more control over the sharpening when you select the method, generate the masks, etc. For capture sharpening, you really want it to be gentle and to be focused on the middle tones, one-quarter tones, and three-quarter tones. Definitely keep sharpening away from the extreme shadows and highlights. Also, for most images, it is best to keep the sharpening limited to the edges. Sharpening surfaces during capture sharpening invites visible noise artifacts. RAW converters are not so sophisticated about sharpening.

The two keys to capture sharpening are masks and protection of extreme shadows/highlights.

Photoshop pros do not sharpen the entire image during capture sharpening. The goal of sharpening is to increase the contrast along the edges in an image either by adjusting the tones along those boundaries (the Amount setting in USM sharpening) or by widening those boundaries (the Radius setting in USM sharpening). Where you have large areas of continuous or nearly continuous color, like a blue sky, sharpening will likely emphasize noise and make it look splotchy.

The first choice is whether to sharpen the surfaces at all, and if you do, how much to sharpen them. Surface sharpening is somewhat of a misnomer. You are stil trying to sharpen important details, but the edges of those details are less well defined. Separating them from noise, dust specks, and the like can be difficult. Sometimes, it is not possible at all and you need to use creative sharpening for those surface details.

Here is an example of a image with important surface details:

The surfaces of the buildings, the bark of the tree, the wall beneath iron fence all contain surface details that could benefit from sharpening. But the sky and pine bough shadows would be adversely affected if the sharpening of the surfaces is as aggressive as the sharpening that your benefit the edges of the buildings and and the evergreen trees.

The TLR Sharpening Toolkit provides several options for capture sharpening. You can choose whether to use Highpass Filter sharpening or Unsharp Mask sharpening (i.e., USM sharpening). Edge sharpening and surface sharpening have their own individual sets of actions.

You can choose from three different masks: a luminosity mask, a color mask, or an enhanced mask that combines the features of both. None of the masks is fully automated. The actions will pause, allowing you to set the appropriate values for detecting edges. The surface masks are just inverted edge masks, with areas between well-defined edges considered to be surfaces.

After selecting the parameters for defining the edge masks (Levels for luminosity masks and Threshold for color masks), a slight Gaussian Blur is applied. The actions will again pause for you to enter a value. This will soften the edge selections.

I selected Highpass Filter sharpening for the image taken just outside the ancient forum of Rome. I applied edge sharpening using an enhanced edge mask. The steps for generating the color mask are similar to those for generating the luminosity mask. Instead of using Levels to define the edges, you use Threshold. A slight blur is applied to soften selection, as with the luminosity mask.

Once both masks are generated, the action create two layers from the masks. The color mask is placed on top and the opacity is initially set at 60%. You can adjust the opacity to allow more or less detail from the color mask to combine with the luminosity mask. I chose 85% for the enhanced mask below.

Once the mask is generated, the actions pause for you to apply sharpening settings. If you choose Highpass Filter sharpening, as I did for this example, you only need to set the Radius. If you choose USM, you need to set the Amount, the Radius, and the Threshold settings. The actions will pause to allow you to enter the appropriate values for the settings. If you are new to sharpening, I suggest you read my tutorial, "Put a Fine Edge on Your Sharpening Skills."

A common question is why use a mask with Highpass Filter sharpening, since it automatically uses edges. If you look carefully at the image below, you will see where Highpass Filter sharpening without a mask would sharpen some of the sky. By using a mask that is generated under your control, you decide where the sharpening will be applied. In this case, although it looks like the sharpening will affect the sky, that's because the layer mask has not yet been applied. Once it is applied, the black masked areas will not be sharpened.

If you elect to use USM for sharpening, you can sharpen with one layer or with two layers. The "Dual Contour" actions sharpen the lighter pixels and the darker pixels separately. The "Dual Contour" actions use the same mask for each layer, but you can apply different USM settings to each layer and you can adjust the opacity of each layer separately. This gives you a lot of control not only over the width of the sharpening halos generally but also over their lighter and darker features. The "Single Contour" actions use a Luminosity blend to avoid color artifacts that can result from USM sharpening.

Capture sharpening is not applied to the extreme highlights and shadows. Each of the capture sharpening actions uses Blend If settings on the Layer Style dialog to limit their application to the middle tones, one-quarter tones, and three-quarter tones.

Here is the same image after capture sharpening:

Overall, the sharpness of the image is improved. The sharpeness lost during digital capture has been restored, yet the image remains free of visible sharpening effects. There are still features that can benefit from additional sharpening, but if we sharpen overall for those features, the rest of the image will be oversharpened. What we need is localized sharpening, and that brings us to creative sharpening.

 

Creative Sharpening

Creative sharpening is done with a brush. My preference is to use a Wacom airbrush and a Wacom Intuos II tablet, but you can use the brush tool with a soft edge. The creative sharpening actions add a Hide All layer mask. In other words, the layer mask is pure black. Set the opacity to a low setting, something like 20% or 25%. Then "paint in" the sharpening, precisely where you want it.

My advice is to be slightly agressive with your sharpening settings for creative sharpening. After all, you will be painting them in. You can even use black paint and paint them back out. Plus you have the opacity setting to adjust the strength of the sharpening effect.

I decided that the buildings in the center of the image and the row of evergreens in front of them could use extra sharpening, so I applied some creative USM sharpening using just a single contour.

You can also apply creative blurring. Selectively blurring elements in an image is an excellent way of adding emphasis to other elements and adding to the appearance of sharpness. If you select the "Creative Blur" action, you will be able to blur the image. As with creative sharpening, this is the place where it pays to be slightly aggressive with your settings and then use brush opacity and layer opacity to fine tune the final effect.

The RAW image for the Roman street woman had a wide depth-of-field. I used a Canon 24-70mm "L" lens, and wide DOF is simplay an expectation for wide angle lenses. I wanted to emphasis the old street woman, not the obelisk or the rest of the activity in the Roman market behind her. Judicious brushing on a Gaussian Blur layer provided extra emphasis to the old woman. The man behind her received a stronger blur effect, the obelisk less. With a low opacity, it is easy to brush in more effect here, less there.

 

Output Sharpening

The important point to remember about sharpening in the early stages of your workflow is to avoid obvious sharpening halos. As you edit the image, those halos will almost certainly become more and more obvious.

Some photographers try to avoid halos during output sharpening. If your image is destined for the Web, that's a good strategy. You do want to avoid noticeable halos. However, if your output is destined for a printer or a film recorder and you avoid halos, your image will not appear as sharp as it otherwise might. You want halos. Just not halos that are excessively wide.

The trick is to apply sharpening so the halos are sharp enough that they provide the maximum in contrast without being so wide that they attract attention. Bruce Fraser, a well-known Photoshop pro offers excellent advice on this point. You want sharpening halos that are 1/50 to 1/100 of an inch in width. If you print your inkjet prints at 180 dpi, halos of 2-3 pixels are best. For 240 dpi, 3-4 pixels. For 300 dpi, try 4-5 pixels. If you enlarge the image 1000%, you can easily count the width of the sharpening halos.

If you applied capture sharpening, the amount of output sharpening you are likely to need is slight. Crop and resize the image, if necessary, before you proceed to output sharpening. If you need to resample, upward, the image will likely lose sharpness. So it is best to wait.

Layer masks are generally unnecessary with output sharpening, if you also use capture sharpening. It is still a good practice to use Blend If settings to prevent blowing out highlights or stopping up shadows. With output sharpening, the Blend If settings allow sharpening to extend a bit further into the highlights and the shadows.

Highpass Filter and USM are available options for output sharpening. If you elect to use USM sharpening, you can choose to sharpen the light and dark pixels separately. For output sharpening, I chose to sharpen the light and dark pixels separately.

The "Dual Contour" sharpening actions sharpen the dark contour first, then the light contour. Generally, sharpening the light contour has a more immediate visual impact than sharpening the dark contour. For the final sharpened image below, I applied the following USM settings: dark (85, 0.8, 0) and light (70, 0.6, 0). The image was sharpened for print, not for the Web. So it should appear slightly oversharpened when viewed on a monitor.

 

OTHER FEATURES

You can use the TLR Sharpening Toolkit to create masks for use with other sharpening tools OR to use with noise removal tools. The surface masks are ideal complements to noise removal tools like NeatImage. Noise removal tends to soften image details. Using a layer mask that keeps noise removal away from well-defined edges means less sharpening after noise removal.

The TLR Sharpening Toolkit is compatible with PS CS. It works only with color images. CMYK, L*a*b, and RGB are supported. The .ZIP file for the TLR Sharpening Toolkit includes a second action set for grayscale images. TLR Sharpening Toolkit for Monochrome Images strips out the actions that use color masks and enhanced masks and supports only single channel, grayscale images.

I hope you find the TLR Sharpening Toolkit to be helpful in your image editing. Enjoy!