Friday, June 15, 2007

How To Buy Digital Cameras & Web Cameras

There are many good reasons to buy a digital camera or Web cam. Digital cameras let you take as many photos as you want without worrying about the cost of film or developing. You can also see the results of your efforts instantly, without waiting for photo developing. Digital cameras and Web cams also provide other benefits—they let you engage in videoconferencing, send photos as email attachments, or even help post images to the Web.

Before you choose a camera, it's important to research the camera models you are considering. Many people make the mistake of simply examining camera spec sheets, but there are a number of performance-related and subjective factors that a spec sheet will not convey. Below, we list some of the factors you should consider when selecting a digital camera or Web cam.

Digital Cameras.
Consider your needs before buying a digital camera. You don't need a powerful, high-end model if all you want is a simple point-and-shoot camera for posting snapshots to a Web page or exchanging images by email. A camera with a shooting resolution of 1,024 x 768 pixels will give you more than enough image quality for these tasks.

Resolution. A camera's resolution refers to the number of pixels (or single dots) it uses to create images. In general, resolution is often used to describe the sharpness and clarity of an image. Typically, the higher resolution a camera has, the better its images will be.
A digital camera with a megapixel resolution means it has a resolution of at least 1 million pixels. A camera with 2-megapixel quality has a resolution of approximately 2 million pixels, such as 1,600 x 1,200 pixels. Most two-megapixel cameras are capable of producing quality 5- x 7-inch photo prints. Currently, you can find many cameras with a 2-megapixel resolution for $200 to $300. Just a couple years ago, a 2-megapixel camera might have cost over $500.

If you want to print 8- x 10-inch photos, the camera’s resolution is important. Some high- quality 2-megapixel cameras can produce decent 8- x 10-inch prints. However, a 3-megapixel camera should print quality full-page prints with very few visible flaws. Cameras with three-megapixel quality are widely available for about $250 to $500.

You can also find cameras in higher resolutions, such as 4, 5, and 6 megapixels. It’s generally accepted that a 6-megapixel camera offers near film-quality results, however, such cameras are still very expensive. However, high-megapixel cameras come in handy if you have a printer capable of printing on larger paper or if you want to crop images and still print 8- x 10-inch photos.

Other important factors. You should consider much more than resolution. A quality 3-megapixel camera may very well produce better images than a cheap 4-megapixel camera. Read independent product reviews, such as those on this Web site, to learn about the image quality of specific camera models.

You should also consider what manual features you want. Just as you can choose between simple point-and-shoot film cameras and advanced film cameras with manual focus, you can choose between very basic digicams and digital cameras that contain a wealth of manual functions. If you buy a more advanced camera, look for one that has easy-to-use menus and controls, as well as a detailed users manual.

If you want a little bit of control over your images but don’t want to spend the money on an advanced model with features you will never use, look for a camera that includes WB (white balance) and EV (exposure value) control. Many cameras that cost less than $400 include such settings. Other features you might consider are a self-timer, macro mode, and an AF-assist (auto-focus assist) lamp.

You should also carefully consider the camera’s zoom capabilities. Many manufacturers print a combined-zoom figured on the packaging or on the body of the camera. Combined zoom includes both optical and digital zoom. Digital zoom is not a true zoom. As you apply more digital zoom, image quality deteriorates quickly. Optical zoom, on the other hand, maintains image quality and is a true zoom. For this reason, a camera with a combined zoom of only 4X (4X optical and 1X digital) will have better zoom power than a camera with a combined zoom of 20X (2X optical and 10X digital).

Many cameras let you capture video and sound. Some also double as Web cams with full videoconferencing capabilities. Many mid- or high-end digital cameras also have burst or continuous shooting modes, manual focus, flash synchs or hot shoes, a threaded lens, and various metering settings.

Also consider the camera’s design. Make sure it is comfortable to hold and that you can operate the controls easily. You should also consider batteries carefully. Cameras that use standard AA alkaline or NiMH (nickel-metal hydride) batteries are convenient because you can easily buy a new set of batteries if needed. However, they generally suffer from very short battery life. If you want to get more battery power before recharging batteries, look for a camera that uses a Li-Ion of InfoLithium battery pack. You will want a spare, though, because if you have battery problems, it will be harder to find a quick replacement. We prefer cameras that ship with a battery charger. Some manufacturers make the chargers an optional accessory.

For storage, most consumer models ship with a flash memory card. There are many types of memory cards, but you can only use cards that are compatible with your camera. For example, Canon cameras use CF (CompactFlash) cards, Sony cameras use MSes (Sony Memory Sticks), and today’s Olympus cameras use xD-Picture Cards (eXtreme Digital Picture Cards). (Older Olympus cameras used SMCs [SmartMedia Cards].) The most common types of flash memory cards for digital cameras are CF, SMC, xD, MMC (MultiMedia Card), SD (Secure Digital), and MS.

Web Cameras.
Like digital cameras, Web cams come in many varieties. In fact, Web cams are some of the most uniquely designed peripherals on the market. But before you buy a model based on its appearance, put it to the test. Many models have designs that leave them wobbling or tipping over whenever the monitor is bumped. Look for a Web cam that has a secure mounting device and a solid, heavy build. Otherwise, you'll spend an annoying amount of time readjusting it.

Nearly all Web cameras are capable of videoconferencing, video chat, posting images to Web pages, attaching video to e-mail, and capturing still images. Some models include an integrated shutter button to take still images away from the computer without having to use the keyboard. In addition, almost every Web cam on the market today uses a USB connection, making it easy to install. Many models also have a built-in microphone. If not, you'll have to provide your own.

Usually, the image quality that Web cams produce isn't anything to write home about. Yet, many models provide sharpness, color accuracy, and focus that are acceptable for videoconferencing. Look for a model that can handle varying lighting situations and hold the focus well into the background. Also, Web cams with automatic white balance are preferable.

Many models have top resolutions of 640 x 480 pixels. Others can reach better resolutions, but may do it with interpolation software. For Web cams, a higher resolution isn't as important for capturing video. Typically, a higher resolution means the camera will grab fewer fps (frames per second) of video, resulting in choppy, jerky motions. A camera with a resolution of 320 x 240 pixels for grabbing a smooth 30fps (television quality) of video is the norm.

Perhaps the best feature about Web cams is their price. Many name-brand cameras currently cost less than $40. In general, you should be able to find a Web cam with a quality performance, software bundle, and features for less than $60.

http://www.smartcomputing.com/editorial/articleht.asp?guid=zdahv6py&article=Articles/Hardware/2000/H0307/62h07.asp