This chapter is from the book
This chapter is from the book
This chapter is from the book
Sharpen
The Sharpen slider is definitely not a panacea—it can't restore details that weren't part of a picture to begin with—but it can create the illusion of a sharper image. It's more of that Photoshop Elements magic, and it's based on some pretty heavy-duty math, combined with an old-time darkroom technique.
How Sharpening Works
Let's start by reviewing the darkroom trick. It's called unsharp masking, and it goes something like this:
- Put the negative of your blurry picture on top of a glass plate, with unexposed film under the glass.
- Make a copy of the negative on the new film, which gives you an inverted version of the negative—a positive. In addition to being inverted, the new copy is slightly distorted because the light that produced it had to pass through the glass plate.
- So now you make a very short-exposure print of the positive. Then on the same paper you print the original negative.
What you get is an image with its edges highlighted because of the slight difference between the negative and the positive. And highlighted edges look sharper and more detailed.
Now let's translate that into mathematical terms to see what Photoshop Elements does. On second thought, let's not. Math is what computers do best, and we don't need to know how it works to use unsharp masking with Photoshop Elements. All we need to do is use the Sharpen Quick Fix.
Try it Yourself: Fix a Blurry Photo
In this task, we use one more photo from the book's website. It's a shot I took at the Boston Flower Show a few years ago. Now, if you live in New England, this show is the place to go in March when you've had enough of winter and you're craving green growing things. But it's held in a big convention center, under artificial light, so colors in photos taken there tend to be, well, odd. I've taken care of that problem in this photo, which is called flowervase.jpg, but it's still a little fuzzy. Let's see if we can fix that.
- Open flowervase.jpg and switch to the Editor's Quick Fix mode (see Figure 6.7).
Figure 6.7 Sharpening is a tricky business; it's so easy to oversharpen. Always use a light touch.
- Adjust the View setting so you can see both the before and after versions of the picture; then take care of any lighting or color fixes you want to make for this image.
- Drag the Sharpen slider to the right. How much? You have to judge for yourself. I like to take the slider all the way to the right, at which point I'm seeing all kinds of graininess and even sometimes bright halos around shapes. Then I back off until the image is as sharp as it can get without the extra grain and halos.
)
That's it! Sharpening is probably the quickest of the Quick Fixes. Just remember to do your sharpening last so you don't undo its effects by changing lighting or color settings.