Digital Focus: Focus Tips, Moving Pictures Between PCs
We demystify a focusing tool called "Unsharp Mask."Dave Johnson
Feature: The Secret of the Unsharp Mask Tool
Do you think your digital camera takes pictures sharp enough to give you a paper cut? Your focus may seem pretty good--until you look closely at some pictures on a big 17-inch monitor. That's when you may see that the focus was ever-so-slightly off. Or your images might be a tad blurry because your camera's focus is always a bit "soft." Whatever the reason, fret not. You can improve your photos with a sharpening tool like Unsharp Mask, which is found in most image editing programs.
Despite the Name, It Sharpens
The Unsharp Mask tool has an odd name, but it's usually your best bet for sharpening a digital picture. Most programs have several sharpening tools. The ordinary ones--with names like Sharpen or Sharpen More--tend to tweak the wrong parts of a picture and make it look grainy, like an old 35mm photo.
The Unsharp Mask tool enhances the apparent sharpness of an image by increasing the contrast in the color of adjacent pixels. But instead of adjusting that contrast willy-nilly throughout your picture--as some sharpening filters do--Unsharp Mask increases the contrast only around natural edges in the picture (regions of dramatic color change).
Sounds great, right? Well, a lot of people skip this tool and use the less-effective Sharpen tool instead. Why? Because the options in the Unsharp Mask dialog box look intimidating. It seems better to just click once than have to fuss with numbers and do some experimenting.
This week we'll end your Unsharp Mask phobia once and for all, so you can sharpen your pictures without worry. Open the Unsharp Mask tool now and take a look at your options. In Paint Shop Pro, you'd do that by choosing Effects, Sharpen, Unsharp Mask.
Strength
Depending upon the program you use, the Unsharp Mask options might have different names. Strength is sometimes called Amount, for instance. This variable refers to how much sharpening you are applying. In other words, it controls the contrast change along the edges in your photo, making dark colors darker and light colors lighter. As a general rule, 100 to 150 percent is the most useful range for this variable. Start with 100 and see if you like the effect. You can always try it again with a higher number. But be careful about increasing it too much; you can end up with a noisy photo with harsh edges.
Radius
This next option lets you specify how far from an edge--measured in pixels--the effect should go. I typically set my radius to 1 for a small image and 2 for larger multimegapixel images. Like Strength, setting this variable too high can result in harsh edges with lighter pixels around all the edges.
Clipping
The last of the Unsharp Mask options is called either Clipping or Threshold, depending upon your image editing program. This variable controls how much contrast must already be in the image before the tool will apply any sharpening. The lower the number you enter, the more sharpening you'll get.
But watch out: If your image is grainy or has digital noise (random pixels of color interspersed throughout), you'll get lots of sharpening in totally inappropriate places. The result? Your photo will look worse instead of better. I tend to start with a threshold of 5 and lower it if I have a very clean, low-noise image. I raise it as high as 10 if my image is kind of dirty.
Also, keep in mind that these values are interrelated. If you use a high Clipping value because your picture was taken in low light and suffers from some digital noise, you may want to increase the Strength to 150 percent to beef up the sharpening effect.
Experiment with the Unsharp Mask tool and you'll find that you can improve pictures you thought were sharp, but were actually a bit soft. It's especially handy for images you plan to print on ink-jet printer.
Dave's Favorites: The New York Institute of Photography
The New York Institute of Photography has been around since 1910; it's one of the oldest photography schools in the world. I had a chance to visit the institute many years ago--back when I lived in the pizza capital of the world--and I still remember the trip fondly.
It wasn't until recently, though, that I thought to look the institute up on the Web. And I found a great site that budding photographers should bookmark.
The institute's Web site is chock full of useful information for any student of digital photography, whether you're enrolled at the NYIP or noodling with your camera on weekends. There are frequently updated photo tips, articles about every facet of digital photography, and camera shopping tips. Best of all is the Photo of the Month Review, in which a NYIP student dissects a photo to explain what works, what doesn't, and why. It's a great opportunity to learn how to improve your own photos.
Q&A: How Do I Move Images Onto Another Computer?
Dave, I have a problem you may be able to solve for me. I have a new digital camera. While on vacation this summer, I borrowed a friend's laptop and downloaded about fifty vacation pictures from the camera to the laptop. Now they're stuck there. How do I get them to my desktop computer? E-mailing them to myself might exceed the time I have left in life. Any suggestions?
--Donald Lenahan, Fort Collins, Colorado
Sure, Donald, I have a few ideas. The easiest solution would be to copy all of the pictures to CD, if your friend's laptop has a CD-RW drive.
Let's assume, though, that the laptop in question doesn't have a CD-RW drive. What are your options now? You can use a floppy disc to transfer the images. Don't laugh; your pictures stored in JPEG format are probably small enough that you can do it in just a few trips. And if some of your files are so big they won't fit on a floppy, all is not lost. Download the free File Splitter utility from PCWorld.com's Downloads section.
This tool lets you split the files into pieces and copy them onto a floppy. At worst, this process will take some time. On the bright side, as long as you have a few floppies laying around, this approach is cost-free. (Note: You don't need to install File Splitter on both PCs.)
The most elegant solution, though, is to use a USB-connected media card reader. I suggest getting a multiformat card reader like the 6-in-1 Reader from Dazzle. I found one for about $40 at PCWorld.com's Product Finder.
After you connect your new card reader to the laptop, copy all the images to a memory card (like the one that came with your camera, for instance). Then you move the reader to your desktop PC and copy the images from the card to the computer. You can leave the reader attached to your PC, since it's the easiest way to transfer images from the camera to the PC.
Hot Pic of the Week
Get published, get famous! Each week, we select our favorite reader-submitted photo based on creativity, originality, and technique. Every month, the best of the weekly winners gets a prize valued at between $10 and $100.
A gentle reminder, folks: We disqualify some really wonderful pictures every week because the submissions don't follow the rules. Be sure to include everything we ask for in your e-mail message, including a description of your picture and your complete contact information, or your entry is wasted!
Here's how to enter: Send us your photograph in JPEG format at a resolution no higher than 640 by 480 pixels. Entries at higher resolutions will be immediately disqualified. If necessary, use an image editing program to reduce the file size of your image before e-mailing it to us. Include the title of your photo along with a short description and how you photographed it. Don't forget to send your name, e-mail address, and postal address. Before entering please read the full description of the contest rules and regs.
This week's Hot Pic: "Three Arches," by Howard Schiff, New York
Howard is no stranger to our photo contest; he has won the Hot Pic of the Week award before. That's due in part to persistence--at least once a month I can expect to find something new from him. But he also has a keen photographic eye and a way with PhotoShop.
About this picture, he says: "This was taken in Central Park. It was shot from a tunnel near the Boat Basin. I did very little editing other than decreasing the brightness of the daylight portion. I also eliminated a few people on the steps."
We want your feedback! Send your comments, questions, and suggestions about the newsletter itself to comments@bydavejohnson.com. If you have a question that you'd like to see answered in the weekly Q&A, send it to question@bydavejohnson.com.
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