As I said in last week’s post, Capture Sharpening is intended to be a gentle round of sharpening to over come the inherent loss of detail during digital capture. And I want to emphasize the gentle part. If Capture Sharpening is overdone it can lead to all sorts of problems in later stages of your image editing workflow.

The Detail Panel in Lightroom’s Develop module has four sliders to control the Capture Sharpening applied to an image. The first two, Amount and Radius, affect the sharpening being applied to the overall image. The next two sliders, Detail and Masking, are used to mitigate the sharpening in certain areas of the image. The Detail and Masking sliders permit the use of higher settings for the Amount and Radius sliders because they “hold back” the effect in areas of the image that should not be sharpened–like a cloudless blue sky.

(As a side note, based on the sharpening setting set on your camera, out-of-camera jpg files already have some sharpening applied to them . This serves as capture sharpening so there is not need for a second round of Capture Sharpening. And I’ll go so far to say that a second round of sharpening will most likely do more harm than good.)

The Amount slider is like the volume control. The further you slide it, the more contrast (darker darks and lighter lights) that will be applied to the edges. And the Radius slider is used to control the width of the halo. Wider halos increase the effect. Over doing either of these sliders can give the image a “crunchy” look. This is where the other two slides come into play.

The Detail slider is used to target the affects of the Amount and Radius sliders to the edge areas. A setting of zero fully dampens the effect and a setting of 100% applies the least damping to the effect.

The Mask slider allows more control over where the affect of the Amount and Radius sliders are applied. At a setting of 0% no mask is generated and the affect will be applied equally though out the image. As the percentage is increased a mask is created, based on the image’s content, that results in smooth areas of the image not receiving any of the affect; while edges receive the full effect.

To evaluate the effect of each of these sliders you should view the image a 100% (1:1) so you can see the halos being created. When the image is at 1:1, or higher, holding down the Alt key (Option in a Mac) and clicking (and dragging) any of the sharpening sliders will generate a monochrome preview of the effect. The previews for the Amount and Radius sliders are straight forward.

The preview for the Mask slider is like a Photoshop mask. As you drag to the right, smooth areas of the image will become black and areas of detail will remain white. Areas of white will have the full effect of the Amount and Radius sliders applied. Areas of black will have no effect applied. And areas of gray will have some effect applied. The preview for the Detail slider is similar but the black and white areas are created around edge detail.

Below is an example of Capture Sharpening being applied to an image. The screen shot only includes a small section of what was visible but shows the effect applied with the four sliders.

Before (Default settings):

After:

I should point out that Lightroom ships with two presets for sharpening. One is called Sharpen - Landscapes the other called Sharpen  - Portraits. The landscapes preset is appropriate when the image contains a lot of fine edges or high frequency detail.  The portrait preset is appropriate for images that contain areas of detail that you want to sharpen as well as smooth areas that you want to protect from being sharpened. This class of image is often said to contain low frequency detail. You can look at the settings used in these presets to better understand what the four sliders are doing.

These presets provide a useful starting point. I’ve created two user presets, that add a little Virbrance and Clarity, to the two sharpening presets. When bringing raw images into Lightroom I apply one of these presets during the Import process so that some sharpening, clarity, and vibrance are applied to all images. Prior to Exporting any image I will go to the Detail panel “tweak” the sharpening slides. (Images that are never exported only get the settings for the presets applied to them but this is provides a better basis to compare and evaluate images in the sorting process.)

The next post on Creative Sharpening shouldn’t be so long.

This entry was posted on Tuesday, March 9th, 2010 at 1:09 pm and is filed under Lightroom, Post Processing. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.