Photoshop's Unsharp Mask Demystified

In my photography workshops, I often hear complaints from students who just can't seem to get a sharp image with their digital cameras. This results in many students looking backwards to the "good old days of film" when almost every image looked sharp as a tack. Fortunately, I've got some comforting news for you; digital images are inherently softer and this will often have little to do with photographic technique. This certainly isn't meant to be used as an excuse to slack off on your technique but rather a true statement that addresses an issue common to almost all digital camera users.

Now before I begin, I should dredge up the old cliche' that there are, in fact, exceptions to almost every rule and photography is not exempt from this tenet. Some images do turn out sharp based on shutter-speed, a steady hand and often applied in-camera sharpening. For anyone wanting to take their digital photography beyond just snap shots, though, I would encourage you to avoid adding any sharpening in-camera. This will limit your ability to resize an image for publication or prints in a variety of sizes and will add unwanted degradation to your image in many cases. So, caveat aside, how then does one sharpen an image? The answer is an initially confusing –albeit important–little filter in Photoshop called 'Unsharp Mask', which, by the way, at first reading sounds like it would create the exact opposite effect that you're trying to achieve.

In Photoshop, open up an image that needs sharpening and follow these simple rules for fast results.

1.) Go ahead and set your image view to 100%. This will allow you to keep a close watch on the edges within the image and help you to see if any unwanted noise, or 'fractals, begin to appear.

2.) Open up the Filters Menu and select 'Unsharp Mask.'

You'll notice that there are three sliders in this dialogue box: Amount, Radius and Threshold. All three are important and I'll tell you from the beginning that most images require settings of their own unless you are adjusting a series of images that were made simultaneously or in a very controlled setting. Experimentation is the key. Before I go into to what each slider means, let me briefly explain to you how Unsharp Mask works.

In the most basic terms, this filter looks for areas within the image where light and dark areas – or groups of pixels– meet. To increase the appearance of sharpness, USM adds varying intensities and amounts of white and black pixels along these edges to give the impression of a sharper edge. So, for example, it will add white, light colored pixels along a dark edge to give the impression of a highlight and darker pixels along a lighter band of pixels to give the appearance of a shadow. This is how the process works in a nutshell. Now, let's get back to how to sharpen your images.

3) RADIUS: I'm going to start with this slider because I believe that this is really the first option that you should consider when adding USM. This option literally refers to the size of the dark/light pixels being added to your image. You will be more successful in your sharpening attempt if you opt to start here. Here is a good rule of thumb that I once heard: if your images contains a lot of detail –say, tree bark, for example– you are going to want to select a smaller radius number because the filter will be able to find a lot of nice, defining edges to sharpen. Add too much of a radius, and the image is going to make your eyeballs pop out with overdone, super unrealistic looking sharpness! With this filter it is often prudent to fall slightly under tack sharp than over it. If your image is generally very soft –say a mist covered field– then you'll want to increase your radius because the filter is going to have a harder time finding a delineating edge, therefore making it more difficult for it to sharpen the scene. In other words, it is going to have to work harder to increase the impression of sharpness.

4.) AMOUNT: This basically refers to intensity –or brightness and darkness– of the pixels being added. Be mindful of this setting because too high of a number will give a very false looking, 'hyper-sharpness' to images. This is why you need to view the image at 100% while adjusting. However, the good news is that you can check the preview option and watch how the amount effects the image by sliding the amount up and down.

5.) THRESHOLD: For ages, I would simply ignore this option because I had no clue what it actually meant. However, once I explain it to you, it should make perfect sense. Taking into account what I've laid-out above, you should now understand that Unsharp Mask lives and dies around finding edges and adding contrasting pixels there. However, what if you have an image where you only want to sharpen a very small portion and not affect the rest? Well, you could do what I used to do and select this small section with a clipping path or lasso tool, feather it and apply USM. However, this is pretty time consuming and often unnecessary. What if you have an image of a bird flying across a nice, clean blue sky. You want to make the bird tack-sharp but in order to do that, you'll need to have a fairly small radius and increase the amount of the pixel intensity. Unfortunately, by doing this you will add a lot of unwanted noise to the sky which is already perfect as shot. The solution? Increase the threshold. In short, an increase in threshold will limit the effect of the USM only to areas with more obvious edges. The more you increase the threshold level, the less the 'softer' areas of the image will be affected. In the case of our bird example, you should be able to set the number to a high enough level to only sharpen the bird and nothing else.

Now that you know the basics the best way to learn is to experiment. However, one final word of advice: always save an unsharpened version of your files. Not only it is good to have a back-up in case you make a mistake but, depending on the size of the file, or how it will be used (art print, magazine, etc.) the amount of sharpening may vary.

Happy Sharpening!
Clay

How will the economy affect conservation?

As we are all aware of by now, the slumping world economy is affecting every area of business. I fear that this is now starting to include the business of conservation. How can conservation be justified when so many people are out of work and there are many who are barely scraping by? Is conservation a luxury of only the wealthy? I am not an economist and I don't pretend to fully grasp all of the workings of government or the means which it takes to run one. However, I am certain that we still remain -good times or bad times- in a critical environmental juncture and that these are issues that we truly cannot afford to ignore anymore.

So, the question still stands then, how can conservation initiatives still move forward without detracting from all of the families who are being effected by the financial meltdown? I am certain that I don't have any kind of definitive answer. One thing that I do believe, though, is that there are still luxuries that we as Americans (and I certainly include myself in this generalization) are unwilling to give up. I'm afraid that if we don't continue to address climate change and species loss aggressively we may find ourselves –in the very near future– in a much more serious situation which requires a closer examination of such things.

This next year will be financially trying for nearly everyone. I hope that with a new administration, and efforts that are being made to ease the markets, things will get better sooner rather than later. However, when the markets once again go on the rise we will still be left facing a multitude of plants, animals and habitats to whom no bail-out has been given and whose only option is to rely on the importance that Homo sapiens places on their continued existence. Let's hope that we make the right decision.

Outdoor Photographer Magazine Article, November 2008

I am excited to announce that November 2008 issue of Outdoor Photographer Magazine is focusing on my work in their Outdoor Photographer and the Environment Feature. The theme of the article will be South Carolina's mountain/temperate rain forest and the conservation successes and challenges that we are facing at the moment. This is a huge honor for me but, more importantly, it will bring our efforts for protecting this critical habitat to a much bigger stage. The article was written by O.P. associate editor Kim Castleberry and she did a really fine job highlighting the issue. I hope that anyone who reads this post will have a chance to check it out!

Clay

Mystery Beetle in Upstate South Carolina

This weekend I found a beetle that I haven't been able to identify, nor have I ever seen it before. Of course, this isn't saying much on both accounts. I'm hoping that someone out there can help me to i.d. this beautiful specimen. My first guess is that it is a member of the scarab family but I could be totally wrong. It was about 1" long and was in some leaf litter near a yellow jacket nest (most likely coincidental but you never know).









I'll be passing this link to Ted over at 'Beetles in the Bush' and put him to the test. Hopefully, he'll be able to tell me more about it.

Clay

The Nature Conservancy Protects Land in Pickens, South Carolina

For nearly a year now, I've been providing images to The Nature Conservancy and Upstate Forever to aide their conservation efforts at the Nine Times tract in Pickens, South Carolina. This tract is one of the richest botanical areas in the Southeast and the largest remaining contiguous tract of the land in South Carolina's Upstate. Plants such as Gorge Goldenrod and one of South Carolina's only two populations of monkshood (see image) exists here. Last week, I received the good news that The Nature Conservancy has purchased 560 acres of the property (Little Pink Mountain) from Upstate Forever and will now be managing it going forward. This opportunity was a result of a concerted effort between Upstate Forever & TNC among others.

Although there is still 1700 acres left to purchase, I feel confident that the remaining land will be protected from development. This is a great win for South Carolina and I'm so thankful to have been able to help in my own small way and I look forward to continuing to creating a photographic record of the property going-forward.

Read the official press release here.

Jumping The Rails in Georgetown

A week ago, I went down to Georgetown, South Carolina to photograph a couple of properties for an upcoming book project that I'm working on. This has been a unique experience for me because I, like most photographers, tend to spend weeks or months working a location when it comes to book projects. In this case, I have have had only a couple of days per property. This has certainly been challenging to say the least but in some ways it has really been a great learning experience. I have worked in the advertising industry for a number of years and have learned from my time as an art director that, when your client is flying you and a photographer hundreds of miles away to photograph a location, you don't have the option of coming home without any images. So, there is something refreshing and liberating about arriving a spot and accepting the fact that, no matter what, you've got to capture the essence of where you are at.

The down side to this is obviously that conditions, such as lighting, view-point, etc, can often be less than optimal. However, it also forces one to make images that you would possibly pass over in a better situation. The image that I've included above is of a blackwater branch that borders the property that I was visiting. "Visiting" is somewhat misleading because, when I arrived, there were heaps of "No Trespassing" signs and, so, since I'm not a fan of buckshot I had to rethink my strategy. It then occurred to me that one of the big reasons that the property was preserved was to protect the riparian corridor for this wetland area. I then realized that if I jumped the guard rail along the highway I would be able to gain a fairly decent view of the branch and as it turned out I was, thankfully, the only one who ended up firing a shot.

Clay

Blackwater, sunburns and (no) gopher tortoises in Aiken, South Carolina

On Sunday a friend and I –photographer Greg Kiniry– had a chance to spend the day photographing a couple of different properties in the vicinity of Aiken, South Carolina. The shoot was for a book project that we are both involved with that will hopefully be completed later this year. After meeting up with Greg a little after 5:00 am (okay...I was late), we rode down on a very foggy morning to the southwestern midlands of our state.

It is amazing how coastal this area appears although the ocean is a few hours away. Longleaf pines and wire grass dominated much of the areas that we were focusing on. One of the spots that we visited was the Aiken Gopher Tortoise Heritage Preserve in hopes of finding and photographing one one of these amazing and threatened animals for the project. Unfortunately, the heat was very intense by the time that we made our way to the preserve and I'm sure that any tortoises in the vicinity were eight feet underground along by then.

One of the sites that we were able to photograph well was a small creek/beaver pond that flowed into the south fork of the Edisto river. This beautiful blackwater wetland reflected the clouds like an ebony mirror and really made it very easy for us to create some nice landscape images. The water was full of wildlife including an anhinga, turtles and warblers. Although early morning and late afternoon are typically best for landscapes, I have found that with an interesting sky early afternoon works really well for these types of wetlands.