How to get your camera rolling

Stephen Pritchard explains what you need to set up your own Netcam

The Internet is held together by the work of gifted amateurs as much as professionals, and Webcams are no exception. The number with university Internet addresses testifies that the hobbyist is still very much at work.

Hi-tech Heath Robinson is a fair description of the process. Broadcast- quality solutions are found alongside equipment begged, borrowed or picked up second-hand. One site, VTV, even shows a wide-angle lens held on to a camera with sticky tape.

Webcams will run on any Pentium or Power Macintosh computer, but they need three other components to work. The first is some form of camera. A true Webcam shows a continuously updated image, so a device that produces a stream of live footage is essential.

An image alone is useless unless the computer understands it, so the second component is an interface between the camera and PC. The third is a link to the Internet, so the images can go live.

Complete, commercial Webcams are starting to appear in the United States that do all this out of the box. They are expensive, and for most applications they are not really any better than assembling a system from its parts - as long as you have the technical knowledge.

The camera is the simplest link. Any camcorder that can output a standard video signal will do the job, although it does need to be able to produce an image even if the tape is full, or left out. Quality is not vital; Internet viewers will go to sleep waiting for a broadcast image to appear. A Sony Betacam SP will make a wonderful Webcam, but second-hand VHS is good enough. Spend any extra cash on a really good tripod.

The new digital video cameras connect to a PC directly, but they are very expensive. Standard camcorder users need a digitiser board to hook the camera up: the Miro DC20 is a typical card. There is plenty of competition at the home video end of the market, with cards starting at a few hundred pounds. Mac users are at an advantage - video-in connectors are standard on models such as the Power Mac 7600 and Performa 6400; this option costs less than pounds 100 on other Performas.

Dedicated cameras are less flexible than camcorders. They have fixed lenses and fewer controls, but win by dispensing with the need for a digitising card. The market leader is Connectix's QuickCam. It comes in mono and colour versions for both Macs and PCs; the colour camera is pounds 199 including VAT. This plugs into the computer's keyboard and printer ports without further fuss.

Connectix's main rival is the mono FlexCam. Video-conferencing systems from BT, Intel or Olivetti could also be pressed into service. In the US, StarDot Technologies sell the WinCam - one for $269, which will work with a modem link, will send a full-screen image every 90 seconds. The company is also producing WinCam Live and Netcam, which claim to work without a host PC.

The real problem for the would-be Internet broadcaster is the Internet connection itself. A truly live Webcam needs to feed its images to a Web server in close to real time. Aside from the programming difficulties - the computer has to capture the image, convert it to a Web-friendly format and bring it into the page - moving images swallow bandwidth.

Companies such as US-based Rearden Technologies sell the connection software, but a standard modem is really too slow for a Webcam, even without the horrendous call costs. ISDN is faster, but still expensive.

According to Internet companies such as UUNet Pipex, the only practical way to operate a WebCam is with a permanent connection to the Internet. Universities and larger companies already have these, but for anyone else, a so-called leased line will cost several thousand pounds a year to rent.

There's also the cost of buying and maintaining a Web server. According to UUNet, a computer could be programmed to sample an image from a camera, convert it into an Internet-ready format and send it online to an Internet company's Web server. The Web server can then push the fresh images out to viewers, creating a virtual movie. It is not truly live; instead it is a series of automatically updated still pictures, which saves on the cost of a dedicated server.

Connectix comes close to the solution with its Quickcams. They ship with Autocapture, a utility that films an image or movie at a predetermined time. It can even put it on to the Internet, if you have the right connections. Finding something to photograph that the world wants to see, though, remains the user's responsibility

Connectix: http://www.connectix.com

or http://www.quickcam.com

Rearden: http://www.rearden.com

StarDor: http://www.wincam.com

VTV: http://www.warp.com/vtv/webcam/