In today’s digital photography world, image sharpness is very important. Anyone with historical photo knowledge, or anyone that grew up shooting film knows that sharpness isn’t nearly as important as composition, subject matter, exposure, and a number of other factors that make a great photograph. This doesn’t change the fact that there are pixel peepers out there, and people expect today’s images to be tack sharp. This guide will help you add the appearance of additional sharpness to your images, without going too far and producing an image that looks obviously over sharpened.
Before we begin, there is one thing that we need to make clear: no software can actually make your photo sharper, it can only give the illusion of added sharpness. If you do not capture a sharp image, even the most expensive professional Photoshop software cannot travel back in time and capture a sharp image for you. What it can do is use a number of tricks to increase contrast in areas to fool your eyes into thinking it looks sharp. And if the viewer is tricked, who cares, right? Well, not really, photography teachers are probably cringing at that last sentence. Of course you should try and capture sharp images in camera, but if you don’t, we’ll take a look at a few different ways you can sharpen images in post processing.
We’re going to assume that you’re shooting RAW image files, and not JPEG. If you’re not, we’ll forgive you, but it’s time to switch that setting on your camera. There are a million reasons that we can’t go in to here, but take our word for it, you should only shoot RAW files. JPEGs tend to use in-camera sharpening, which is bad for a number of reasons, but mainly because it takes the control away from you. Every image will require a different degree of sharpening, or no sharpening at all. In-camera sharpening also sharpens the entire image, something that doesn’t really make sense for the out-of focus areas (or bokeh).
So by now you should realize three things: Always shoot RAW files, post-processing will only make your images appear sharper, and always shoot RAW files. Yes we said that twice, it’s that important. Next let’s explore what sharpness is exactly. Put simply, image sharpness is a combination of image resolution and acutance, or the appearance of edge contrast. A number of things can cause un-sharp images, with some of the more common causes being camera shake, subject movement with too slow of a shutter speed, soft (low quality) lenses, and diffraction.
With all of that out of the way you should have a solid understanding of what sharpness is, and how you can do your best to obtain sharp images in camera (think fast shutter speeds, tripods, VR or IS lenses). Now it’s time to dive in and look at how Lightroom and Photoshop can help you increase your image sharpness.
In this article we’re going to deal with Lightroom, as it is a simpler, more user-friendly post processing software, and often a jumping off point for photographers before they purchase Photoshop. We’ll go over sharpening using Photoshop in another post, as there are many more options and techniques using that software.
This is a 100% crop of the focal point in a portrait (the nearer eye). The photo below is straight out of camera (plus some color and exposure corrections). In reality, the eyelashes are definitely sharp enough for me, but this will be a good example to demonstrate some moderate sharpening, and over-sharpening.
In the Lightroom Develop module, you’re given a simple sharpening adjustment panel under “Details.” There are four sharpening sliders: Amount, Radius, Detail, and Masking.
Let’s start with the masking slider. This is the simplest way to choose what areas of the image you want sharpened. While it will still sharpen the entire image, the farther you move the slider to the right, the more selective the sharpening will be. So as you increase the masking number, Lightroom masks out everything except the high contrast edges. By pressing the Alt/Option key as you mocve the slider, you will see the areas in white that will be sharpened.
If you want to be even more selective with where your sharpening is applied, you will have to use Lightroom’s Adjustment Brush, which allows you to “paint” over only the areas that you want the mask to apply to, and then adjust the sharpness to your liking.
Now let’s jump back to the top of the sliders, to the Amount slider. It should come as no surprise that this slider controls the overall amount of sharpening applied to your image. It works by increasing the amount of contrast between pixels to give the illusion of increased sharpness, and it does a great job at it. With your image zoomed in to your focus point, slowly slide the slider back and forth until you get something that looks good to you. Remember, photos that are over-sharpened look worse than if you didn’t touch those sliders at all.
The next slider is the Radius slider. This controls the radius of the pixels surrounding edges within the image. For example, if you select a radius of 1, Lightroom will sharpen 1 pixel around each edge that it detects. Selecting 2 means it will sharpen 2 pixels, and so on. We highly suggest keeping this number as low as possible, as higher numbers tend to give you some really strange looking halos and shadows around edges.
Finally we have the Detail slider. This slider determines how sensitive Lightroom is to edges. If you choose a higher number, Lightroom will sharpen edges that have less contrast (think skin pores), and lower numbers will sharpen only edges that are high in contrast (think eyelashes against pale skin). Again, usually the lower the number the better.
Here is the same image with what I judged to be a moderate amount of sharpening for this image:
Ok, so now finally a word on over-sharpening. This is a common mistake that new photographers make. You drag those sliders way over to the right, and you get this gritty, crazy look. You think it looks great because it’s different, and edgy, but believe us, as you grow as a photographer, you’ll go back to those images and wonder, “What was I thinking?” So as you are sharpening your image in Lightroom, remember to take a look at the image, and ask yourself if it looks too sharpened. Is there excess noise? Are there strange halos or artifacts visible in the image that weren’t there before you sharpened it? If so, scale it back a bit, you’ll thank yourself later. Here is an example of the image with way too much sharpening. See all the artifacts and noise? This is no good, take this as an example of what not to do:
In the next article we'll delve into the variety of ways to sharpen using Photoshop, which will give you even more options and control over your final image.