(EOS 7D, 17-40 @ 24mm, f8, 1/600, ISO 400, 5:36 pm)
There is an old saying …. You cannot make a silk purse out of a sow’s ear. That truism holds for photography as well. In order to make a good finished product, you have to start with a quality image. When we are talking about image sharpness, photographers are specifically talking about the definition of edges. Critical parts of the image will be razor sharp … that is, you can easily tell the difference between this and that.
Image sharpness starts even before you press the button on your camera. As Ansel Adams was fond of saying, “There is nothing worse than a sharp image of a fuzzy concept.” The essence of photography is being able to communicate a specific moment to those who are not present, or to interpret it for those who are there. Entire lifetimes can be spent in pursuit of the one perfect image, and many of us have a difficult time translating our vision into a photographic print. But this article is not about photographic vision, it is about making certain that what we do capture is decent enough to display.
Once you have the concept, exposure, and the composition of your image figured out, there still remain the technical aspects of making a sharp image. These begin even before the shutter is released. Here are some things that can help improve image sharpness:
Once you have done everything right and captured a “tack-sharp” image on film (or your memory card these days!), you are well on your way to getting a sharp print. If you have not succeeded in doing that, the rest of this discussion will not really help you a whole lot. There is only so much that can be done to salvage an image that was not properly made. In other words, the best thing that you can do to ensure a sharp image is to brush up on your field techniques!
The remainder of this discussion is about what to do in the digital darkroom (your computer) once you have properly captured an image. There are equivalent techniques used for film, and that is where these tools and techniques were originally developed, but most people are shooting digital these days. Most who are shooting Fine Art images shoot in the RAW format so that they can tweak every last bit of information out of the data their camera has captured, and by its very nature, a RAW image needs to have sharpening applied. It can be argued that it is not needed if you shoot jpg, because the camera has already applied sharpening to your image, but even there, some tweaking is often needed.
What is sharpening and what does it do? In a nutshell, sharpening enhances the edge contrast to make these edges better define the subject of a photograph. It makes the differences between tones slightly more distinct so that the line is better defined and appears more dimensional. Sharpening cannot fix poor focus or camera shake problems, it is limited by the data you present. Good sharpening, properly done, is said to be invisible. It simply counteracts the effects of processing pixels to make the edges as distinct as they are supposed to be. Sound vague? It probably should. Until you have seen properly sharpened images, you are likely to think the soft ones you have printed are just fine. Once you make the adjustment yourself, you very quickly begin to notice the difference.
There are several methods to choose from when sharpening your images, and like most things in photography, the choice is yours. A simple Google search for “image sharpening” returns over 11 million hits. You can choose to use only the most basic sharpening that is applied automatically, or you can tweak every last detail. It is a very simple fact that the larger you print, the greater the need becomes for custom sharpening to be applied. Sharpening is not VooDoo Magic, but it does require some study and practice to perfect.
Bruce Frasier and Jeff Schewe (pixelgenius.com) are the acknowledged experts when it comes to image sharpening, and Frazier’s book, “Real World Image Sharpening” is still the textbook of choice for digital image sharpening. Without going into detail, (you can read Frazier's book) the principles that he uses are the basis for the sharpening algorithms that are found in several software packages, most notably Pixel Genius’ PhotoKit Sharpener, NIK software’s Sharpener Pro, and all of Adobe’s products (Lightroom, Photoshop, and Elements). No matter which package you ultimately decide to use, it will take practice to perfect your post-processing technique. This includes noise reduction and image sharpening. A good website tutorial on sharpening can be found at http://www.cambridgeincolour.com/tutorials/image-sharpening.htm. (check out their full range of tutorials!)
A sharpening workflow includes:
There are dozens of software packages available to accomplish these tasks, and even the free ones available online offer at least basic functionality. I am not going to argue about which is best, or even appropriate for you. Use the tools you find most comfortable. I am most familiar with Lightroom, which uses Adobe’s Camera RAW engine. In Lightroom, there are several places you can adjust sharpening that correspond to Frazier’s 3 step sharpening theory (I believe Aperture and most others do similar things):
Although Lightroom and Aperture produce “good” results, finicky users are always going to end up wanting more from their images. Photoshop allows you to use your personally preferred method for both noise reduction and sharpening. You can use one of Photoshop’s built in sharpening methods, write your own action, or buy a plug-in. The built-in methods are adequate, but not excellent. Actions are much faster in the long run, but most still need customized. Plug-ins are specialty tools that have been developed for this function and usually work exceptionally well. I use all of the above, but for everyday use, I find the level of control in Lightroom to be adequate. Only as I print larger Fine Art prints do I need to use the custom tools, layers, and masks that Photoshop provides. Your mileage may vary.
If you are going to spend the money on tools like Photoshop, NIK Software’s Sharpener Pro, PhotoKit Sharpener, Photo Ninja (formerly Noise Ninja), Neat Image, Topaz, etc, know that you are going to have a learning curve and make sure that you are going to get your money’s worth. Work with your tools and try various methods to find out what works best. There is no single tool or method that is exclusively able to produce excellent output, it is the operator who does that! All of the above (and more!) are tools to help you achieve the best possible print from your image.