Digital Focus: Accessory Lenses, Choosing CompactFlash Cards

Three kinds of accessory lenses and how to use them; plus, how to choose memory cards.

Dave Johnson

Using Accessory Lenses

Last year, wandering around the Grand Tetons of Wyoming, I accidentally blundered into one of the most exciting photographic opportunities I'd ever experienced: A coyote was actively hunting down a rabbit right before my very eyes. As you can well imagine, I set up my camera and started snapping photos.

It was a once in a lifetime experience, to be sure. But unfortunately, the photos were underwhelming. In fact, I didn't consider a single shot from that sequence to be a "keeper." Why? Had I been equipped with an SLR, I would have used a beefy 500mm lens. But my digital camera's wimpy 3X optical zoom didn't have the reach I needed to shoot the scene, and the action was too small within the frame.

Finding Lenses

Don't let that happen to you. While you may not need to photograph a predator bearing down on prey in the mountains of Wyoming, you've no doubt run into situations in which a wider view or a longer zoom would have helped you take the perfect picture. Most digital cameras include a zoom range that's adequate for 90 percent of the photos people routinely take. But accessory lenses let you get rare and memorable shots that your ordinary lens can't capture.

How do you connect these lenses to your camera? That depends on the camera. A few cameras, like the Kodak DC5000, are designed to directly accommodate screw-on lenses, thanks to screw threads on the front of the built-in lens.

Those cameras are the exception, though: The vast majority of cameras need a lens adapter. Lens adapters are intermediate rings or tubes that snap or screw onto the front of the digital camera and mate with whatever lens you plan to add. Adapter rings are inexpensive and typically allow you to connect a wide assortment of standard accessory lenses to your camera.

You can find accessory lenses in a variety of places. You can start by surfing to your camera manufacturer's Web site; a local camera or computer shop might also have a selection of lenses. In my experience, though, your best bet is Tiffen. Tiffen sells add-on lenses for virtually every digital camera on the market, and their Web site makes it easy to figure out what you need to buy for your particular camera.

Power, Diopters, and Other Concerns

You can add three kinds of lenses to your camera: wide-angle, telephoto, and macro (also called close-up).

Wide-angle and telephoto lenses are identified by their X power, such as.5X, 2X, or 3X. If a lens is marked 2X, it doubles the focal length (and thus the magnification). Telephoto extensions are great for pulling in distant scenes, and obviously give you the greatest magnification when you extend the camera's built-in zoom all the way as well.

Wide-angle lenses have an X rating of less than 1; common wide-angles are.5X and.75X. Very wide lenses can distort your scene (like the fish-eye effect you've seen from extremely wide-angle lenses).

Macro lenses are used for extreme close-ups. You can use macro lenses to take pictures of coins, jewelry, and miniature figurines, for instance, or go outside and shoot bugs and leaves. Unlike other lenses, though, close-up lenses are described by diopters, which is an indirect measure of focal length. You'll typically see close-up lenses in strengths from +1 to +10, and you can screw them together to increase their strength--so a +7 and a +10 would give you a +17 magnification, which is enough to see clearly the legs on a grasshopper.

When you first start shooting with accessory lenses, watch out for an effect known as vignetting. That's what happens when, because there's an extra set of optics in the pipeline, the camera barrel actually gets in the picture and cuts off the corners of the photo. Keep an eye on the LCD display for this effect (you won't see it in the optical viewfinder) and avoid it by not going to the extreme end of the camera's zoom range.

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Mini Review: Ricoh Caplio RR10

Like one of those late-night TV commercials littered with marketing come-ons such as "what would you pay" and "but don't answer yet," Ricoh's new Caplio RR10 is a wonder of modern convergence that does a little of everything. It is a digital camera, Webcam, video camera, digital voice recorder, and MP3 player. Heck, you can rig it to display PowerPoint slides on a television. And yet it costs just $449.

The inch-thick Caplio RR10 is 4.5 inches long and 2 inches wide. It fits comfortably in your hand and doesn't really look like a full-featured digital camera--it's almost small enough to serve as a spy camera. It's a 2.1-megapixel camera, though, with a 2X optical zoom and integrated flash.

Indeed, I looked and looked for shortcuts and missing features, but found surprisingly few. The flash reduces for red eye. You can use exposure compensation to adjust for backlighting. There's an action mode for shooting a rapid sequence of photos. You can even make short MPEG movies.

But there's a lot more to the Caplio RR10. Ricoh designed it to be a multifunction multimedia gadget. Using its USB cradle, you can copy the camera's pictures automatically to a folder on the desktop, and the Caplio RR10 can even convert the images to a different resolution and file format in the process. Now that's service! You can copy images to the Caplio RR10 and use its video-out capability to display them on a TV. And best of all, it can play MP3 files via an integrated headphone jack. You'll want to get a larger memory card to listen to much music, though. The camera ships with just an 8MB SD (Secure Digital) card.

As cool as the Caplio RR10 is, MP3 playback is exceedingly poorly implemented. Songs must be in the relatively uncommon 96-kbps format, and something quirky in the encoding process requires you to use the bundled MusicMatch software to convert your songs to the right format. Other encoder programs don't work. The bottom line: The Caplio is perhaps the single most inconvenient digital music player ever sold.

And that's too bad, because this is one heck of a great 2-megapixel ultra-portable camera that also does double duty as a multimedia machine.

Q&A: Choosing Memory Cards

Is there any real, measurable difference between "name-brand" CompactFlash cards, such as the ones from Sandisk, and the generic cards one can easily find on the Web, at much lower prices?

-- Rich Wasserstrom, Richmond, Virginia

That's a good question, because the cost indeed varies dramatically depending on where you shop. The most important difference among memory cards is the speed at which data is written from the camera to the card.

Speed might not seem like a big deal, but writing a 3-megapixel image to a CompactFlash card can take some time--and depending on which camera you own, it can affect how soon you can take another picture.

Check out the specifications of your memory card before you buy. Typical speeds for consumer CompactFlash cards are in the neighborhood of 4X to 8X (where 1X is 150 kbps), and you can buy super-fast 12X professional CompactFlash memory. Obviously, speed has a direct impact on the memory card's price tag.

Send your questions to question@bydavejohnson.com, and please be sure to let me know where you're from.

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're disqualifying some really wonderful pictures every week because the submissions aren't following the rules. Be sure to include everything we ask for in the e-mail message, or your entry is wasted!

Here's how to enter:

Send us your photograph in JPG format, at a resolution no higher than 640 by 480 pixels, to hotpic@pcworld.com. Entries at higher resolutions will be disqualified immediately. 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 of the photo 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:

Sunrise by Stewart Midwinter, Calgary, Alberta

Stewart says of this dramatic sunrise scene:

"I was staying on the Fay Glacier, above the Valley of the Ten Peaks near Lake Louise, Alberta. On the final morning, I awoke at dawn to hear the wind howling over the glacier, and went out to check on the weather. The strong westerlies were setting up standing waves over the Rockies, and the resultant lenticular clouds were quite evident in the colorful dawn. I snapped a few pictures, but by the time I could rouse a few others to come and look, the colors were already fading."

Thanks, Stewart--but that still doesn't tell me what lenticular means.