How web broadcasting works
Webcams are those handy little cameras that attach to your PC and send images to a web page that can be viewed by others. This enables you to share daily life events with friends and family in other parts of the country or the world, or to arrange a video-conference with colleagues and maintain long distance relationships of all kinds. Of course the number of ways to use this technology is limited only by your imagination.
But before you buy a webcam, it pays to understand a little about how the technology of broadcasting images over the Internet works.
Webcams provide 'real time' images of people places and events that can be viewed 'live' on a web page. The broadcasting end has a camera that captures the images, feeds them into a computer to an ISP and out to viewing pages across the Internet. There are two different types of broadcast: streaming images, where the images are a constant stream downloaded in video format or Java, where the images are captured at fixed time intervals and refreshed on the web pages at a rate fixed by the broadcaster.
The Applications - What are you intending to broadcast, and to whom?
There is a wide range of uses of webcam technology. Some examples include personal 'Big Brother' style diaries, sharing of family events, workplace security, video conferencing, virtual tourism, road traffic management, weather watching, event broadcast and a host of others.
Before you make a choice about any webcam equipment, it helps to decide exactly how you want to use the technology, in other words, what you are intending to broadcast. This decision will impact upon the type of camera you use, and how you use it.
A second consideration is, who will be viewing your content? What level of quality is expected? This will help determine the type of camera you use, the software involved and your Internet connection. Of course, your Internet connection may be a limitation on how much you can do.
The requirements for video conferencing are different from the requirements of workplace security, which are different again from the requirements of sharing a family event.
The physical components
There are a number of physical components required to make web cam technology work. At the top of the list is the camera itself. Then, depending on the type of camera you use and the way in which you want to deliver the content to the Internet, you may need to incorporate video capture hardware in your computer. Some software is required to help you process the data, and Internet connection is required and a web page into which the data is fed.
CAMERA CHOICES
Your choice of camera depends somewhat on what you are intending to show. If you need to reach a large public audience yo may want good quality camcorder or megapixel camera that captures high quality images. If it's just for seeing who's at your front door or keeping an eye on the kids in their playroom, then it may not need to present high quality images. If you are intending to use it outdoors, it will need to be weather proof and you may need to consider sun and UV protection. Available power supply and any robotic requirements for camera movement and focus are extra considerations.
Dedicated webcams
The most basic webcams connect to a PC using a simple USB connection. A wide range of cameras with accompanying software at a range of prices is available for this type of application. Simply search though Myshopping.com.au to compare prices and specifications. Dedicated webcams are simple to install and easy to use, but come with limitations that affect the quality of the images, such as low number of frames per second (refresh rates) and resolution (pixels per inch).
Camcorders and security cameras
Higher quality images and more camera control come from using camcorder and security cameras. To use these devices you will need to add a video capture card to your PC. Once you have that installed however, you can use a wide range of cameras from broadcast cameras to miniature spy cameras. You can include variable lens options, filters for daylight and low light situations, as well as robotic controls for panning and focus adjustments. You can search through Myshopping.com.au for camcorder selections.
Integrated cameras
An integrated camera combines the camera and the optical hardware with a video server, and as such requires no additional software. They can be used in network situations or as stand-alone devices for monitoring progress on a construction project for example.
Megapixel cameras
Network megapixel cameras combine network capability with high quality digital camera technology. These cameras offer excellent quality but this creates large files sizes, therefore they have limited application in constant streaming video. However for interval refreshed archive image collection, they are ideal, providing a constant record and high quality.
SOFTWARE
If you are not using an integrated camera solution, you will need to install an encoding program like Webcaster or MediaCaster to transfer your images to a web page.
At the receiver end, when web surfers browse the internet and wish to view live video on the web for the first time, they will need to download dedicated applications that show the content such as an ActiveX control, Windows Media player, Flash player or the like.
INTERNET CONNECTION
Finally, you need an Internet connection. The hardware you will need may include a modem for dial-up connection, or modem/router for a broadband solution. Naturally the higher the quality you want, or the faster refresh rate you want, the more bandwidth you will need. ADSL (Broadband) is going to offer you the best solution, but keep in mind what your Internet connection when you are making choices of cameras and feeder software.
Webcam applications work well with wireless solutions. Make sure when you are purchasing a camera or network video solution that it is compatible with any wireless system you may be using in a LAN.
Key considerations
The specifications that are variable with webcam applications, and are affected by camera type, web interface and Internet connection, include the number of frames per second and the image resolution.
Frames-per-second is the number of times a still image flashes by in a second to give the appearance of moving pictures. In Australia, the standard television PAL format is at 25 frames per second. A webcam with up to 30 frames per second will show normal video images. But the more frames per second you demand, the more bandwidth, memory and processing power is required.
Resolution is measured the number of pixels per inch. High quality photographs require a high resolution. But the standard for web images is a low 72 dpi. Higher resolution images will not be of any better visual quality, just slower to upload and download.
Use Myshopping.com.au to compare different webcams, camcorders and digital cameras. You can compare the prices and specifications of the different products and brands, and a wide range of reputable vendors. |
