Like many things, digital photography has evolved the manner in which photographs are taken, processed, used, and shared. Something that has taken many photographers’ time to understand is the difference between how images are shot and saved digitally versus their film counterparts. One of these differences is the anti-aliasing filter over the sensor.
The technical details of this are out of the scope of this article, but the takeaway is it leaves images slightly blurred. The sharpest unprocessed image taken with a digital camera will not look sharp without some post-processing. This article discusses sharpening these images with Adobe Lightroom.
The Adobe Lightroom Sharpening Tool
There are four sliders used to sharpen images in Lightroom, Sharpening, Radius, Detail, and Masking. Many people believe that the Sharpening slider is the only one they need to use.
The Sharpening Slider
After all, if you want to sharpen an image, just increase the Sharpening slider, and it gets sharper, right? On some images, this is enough, but if the Sharpening slider is all you use, you are doing your images a disservice.
The Radius Slider
The radius slider is the second control under Lightroom’s sharpening panel. When you are sharpening an image in Lightroom, you are actually sharpening pixels. This slider determines how much of the pixel gets sharpened. In particular, it controls how close to the edge of each pixel sharpening occurs. How you use this slider will be determined by the type of image you are sharpening.
The Detail Slider
Next in the panel comes the detail slider. As the name implies, this slider controls the finer details of sharpening. This is where you can really make those edges sharp, but also where you can push too far. There is a fine line between sharp and artificially harsh.
The Masking Slider
Finally, one of the most useful sliders is the masking slider. This doesn’t control the sharpening so much as it determines what does and does not get sharpened. The more you push the slider to the right, the less detail will be sharpened. This is great to concentrate on the major edges and details of the scene without leaving noise in areas that don’t need sharpening. A great example is a blue sky.
Practice, Practice, Practice!
Sharpening takes a lot of practice to do correctly. Almost all beginners want to sharpen too much. The correct amount will be determined by the type of image, personal taste, and how the image will be used. There are several tricks you can use to help you with your sharpening efforts.
In the upper-left corner of the sharpening panel is a small target symbol. Clicking on that will change the cursor into a cross. Now, as you move around the image, you can see the zoomed-in view in the sharpening panel move. Click on an important part of the image to see the effect of your sharpening on a critical area while leaving the main image zoomed out. This is perfect for sharpening portraits and making sure the eye is sharp.
Using the Alt Key Overlay
Another little know feature of the sharpening panel is the use of the Alt key (Option key on Mac) while using the sliders. Using this key while clicking on or moving the slider gives you a different perspective on the image that can aid greatly in getting a correctly sharpened image.
Using Alt with the Sharpening slider will shift the image to greyscale. This makes it easier to see the effect of the slider without the distraction of colors. On the radius slider, the Alt key will give an overlay showing the amount of edge that is being sharpened. Using the Alt key on the detail slider gives a similar but much subtler overlay showing how much detail is being sharpened. The best use of the Alt key is with the masking slider. This will show you what is and what is not being sharpened.
Sharpening Tips! Get Your Sharpening Tips!
Whether done by settings in the camera or by software during post-processing, all digital images need some degree of sharpening. The trick is to get good crisp sharpening in the detail without introducing halos, noise, or harsh, artificial-looking edges. Follow this Adobe Lightroom sharpening guide and experiment and get your images razor-sharp.