Labs

Which Webcam?

In this article we'll reveal the best webcam on sale today. But if you want to understand why the winner comes out on top, you'll first need to know a little about how webcams work.

Just like a digital camera or a digital video camera, webcams first captures light using a lens. The lens, which can be made of glass, or more usually plastic, focuses the light onto a clever device called a CCD. This is a piece of light-sensitive circuitry that measures the brightness of light being shined onto it. In order to capture detail, the CCD is broken down into lots of little chambers, called 'photosites', each registering the light intensity of a different part of the image. The number of photosites in your CCD determines the number of dots (or 'pixels') you'll get in the captured picture - this is called the camera's resolution. The higher the resolution, the finer the 'grain' of the picture, and the more detail the camera can record. Most of the cameras tested here have a resolution of 640 pixels wide by 480 pixels high.

The combined quality of the lens and the CCD resolution will determine how sharp a webcam's picture is. But webcams don't just capture still images, they capture video, so it's not enough just to have a well-defined picture - you want smooth movement, too. This is determined by the number of times per second that the camera can take a picture and transfer it to your PC - known as the frame rate. The faster the frame rate, the more fluid and natural the movement in the video will appear. A picture with a slow frame rate looks choppy, like the effect of a strobe light at a disco, only a lot less exciting.

For smooth movement you need a frame rate of at least 30fps (frames per second). All the cameras in this group test, bar the Sony WebCam Ezee Kit claim to be able to meet this standard, but usually not at 640x480, their maximum resolution for video (though several cameras can capture higher resolution still images). To get the best possible refresh rate, you may have to sacrifice some image quality and reduce the resolution to 320x240 or less.

One of the reasons for this is that capturing video generates masses of data, making it hard for the connection from your webcam to your PC to cope when both frame rate and resolution are high. USB is the most common connection, but this isn't quick enough for full-resolution 30 fps video. There is an answer, though. Intelligent webcams, such as those here from Logitech and TerraTec, actually compress the video before it's sent down the USB cable. This allows higher frame rates, as less data needs to be sent for each frame.

So, the webcam itself simply captures video and sends it to the PC. In order to view it, you'll need software. All the webcams we tested came with plenty of software for recording video clips and still images, but not all provide software for editing video or stills. If you're using Windows 95 SE or later, NetMeeting is an option in Windows Setup, so you can use your webcam for videoconferencing. However, don't forget that videoconferencing also requires a modem and an Internet connection to work. And to be honest, the frame rates you get from video transferred over a dial-up modem is laughably bad. Unless you're only after a bit of a giggle, a broadband connection should be on your shopping list, too.

Logitech, Creative and TerraTec also include surveillance software with their cameras, but you can still buy your own for the other webcams. This is often the case: even if a webcam doesn't officially perform a certain function - such as taking still pictures - the right piece of software will often provide the missing facility.

What makes a good webcam?

Choosing the right webcam starts with the two key areas we've already discussed: picture quality and frame rate. The trouble is, the specifications you'll find on the boxes are all very similar, but this doesn't mean that every webcam delivers the same quality and frame rates in practice. For starters, the quality of the lens is a big variable that the specs won't reveal. Fortunately, Computer Buyer is here to help: by testing eight of today's best webcams in our Labs, we're able to reveal how they really measure up.

You also need to consider any extra hardware features. All webcams can take still images, but those with dedicated shutter buttons make it that bit easier. The Creative PC-Cam 300 1.3MP and Logitech ClickSmart 310 have a real party piece for still pics: they can be detached from the PC and used outdoors just like a normal digital camera. The Creative even has a flash, making it much more versatile.

An LED that tells you when the webcam is activated might help you avoid ending up on You've Been Framed. Also, the mount or stand is a critical consideration, as some webcams are more suited to notebooks while others are tailored to sit on top of a monitor. Those that offer a variety of mounting options are best. The Philips is the most flexible here, being supplied with a telescopic stand.

Bundled accessories can also boost the value of your webcam. Some kits include a microphone - essential for capturing audio alongside your videos - while others come with carry pouches. Finally, don't forget aesthetics - you might want a device that fits in with your existing colour schemes. Generally, the smaller the camera, the less intrusive it is.

As we've said already, if your webcam doesn't come with the software you want, you can always go out and buy it, fairly safe in the knowledge it should work fine with your unit. However, buying software separately is an expensive business, so you ideally want a webcam that includes all the applications you're after. Also, some software packages are simply better than others - read the individual reviews to find out which. For example, Philips includes a neat application launcher that lets you easily start any of the bundled programs, rather than having to search for them in the Start menu.To measure 2D performance, we used our usual benchmarks based on applications like Microsoft Word, Excel, and CorelDRAW. These show us how well these notebooks match up to a desktop Evesham PC equipped with an Athlon XP 2000+ processor (which scores 1000).

To see how well they'd cope with modern games, we used 3DMark 2001 at its default settings. We also tested with 3DMark 2000, to give slower notebooks a chance to show what they can do with older games.