The world widens on Webcam
It must be the voyeur in me. Among my favourite websites are EarthCam (
www.earthcam.com), Webcam Central (
www.camcentral.com) and Camscape (
www.camscape. com) - three sites that provide links to a huge selection of webcams across the globe.
I can watch the sun rise over Moscow's Red Square, the comings and goings in a carpenter ant colony in Michigan or the traffic in London's Trafalgar Square. Webcams have become part of the internet landscape, informing, entertaining and occasionally enlightening. As EarthCam's website declares, this is "where the world watches the world".
But, until quite recently, webcams - or network cameras as they are also called - were mostly bulky, expensive and difficult to set up. That has changed over the past couple of years with a new generation of network cameras designed for the consumer and small business markets.
These network cameras are small, reasonably priced and designed to be set up by those with little or no network experience. Increasingly, they are wireless devices designed to be integrated into a WiFi 802.11b network and to be monitored and controlled over a local network or remotely over the internet using a standard web browser anywhere in the world.
They can be used for basic security functions such as monitoring a home while the householder is at work or on holiday, monitoring an office for intruders or keeping a watch over children and pets.
I decided to take a look at the latest network cameras available from three vendors: Axis Communications (
www.axis.com), a Swedish-based company that pioneered the network video camera market, Veo (
www.veo.com) and D-Link (
www.dlink.com), the home networking market specialist.
All the network cameras I tested are designed to work with a home or small office Ethernet network and work best with a router device and a high-speed broadband internet connection.
Most modern routers - including wireless routers such as the D-Link DL-624 I was using - come with four or more standard Ethernet ports and use a technology called DCHP (dynamic host configuration protocol). DHCP automatically hands out a unique network address to each device on the network - a feature that makes setting up any network device including a WebCam much easier.
Nevertheless, as I discovered, it also helps to be able to contact a techie expert when you hit an unexpected problem such as navigating a way through a security firewall.
The Axis 205, which costs about $200, claims to be the world's smallest network camera. It fits easily in the hand and is designed for indoor use only. The camera, mounted on a small stand, plugs into a home or small office network using a standard Ethernet cable, which, somewhat surprisingly, is not supplied.
I found the Axis 205 easy to set up - it is simply a matter of connecting the camera to the network, plugging the power adapter in and waiting for the status indicator on the front of the camera to turn green signalling that the camera has successfully received an IP address from the DHCP server.
You are then directed to visit the AxisCam home page and follow the instructions to complete the set-up. As part of this process, the camera receives its own Internet Domain Name, which you then use to view images from the camera remotely. The process operated flawlessly for me and the camera works with most systems including Windows, Mac OS and Linux.
Once set up, the Axis 205 delivers reasonable quality video at up to 30 frames a second and three different resolutions up to 640 by 480 pixels. The Axis 205's low price and easy set-up makes it a good choice if you want to set up multiple indoor network cameras.
For $100 more, if you live in the US or Asia, Veo's Wireless Observer camera is a somewhat larger wireless indoor device with pan and tilt functions. (Veo also sells a standard Ethernet wired version for $200.)
The Wireless Observer's built-in WiFi connectivity makes it easy to complete the set-up, provided of course that you have an existing wireless network. Like the Axis, the Veo unit streams 640-by-480 video at 30 frames a second on my local network, while offering limited pan and tilt via its web-based viewing page.
The set-up guide is adequate and deals with most, but perhaps not all, of the problems a user is likely to encounter. Nevertheless, the camera has some neat design touches, for example displaying its IP address in a small liquid crystal display. Software that comes with the camera can be set up to send an e-mail automatically with a snapshot image, view multiple cameras at the same time and capture snapshots and video to a networked personal computer.
The D-Link SecuriCam DCS-5300W Internet Camera is the newest product in D-Link's internet camera range and costs about $300 in the US - it is not yet available in Europe. The DCS-5300 is the most feature-packed and impressive of the three cameras I reviewed and the most solidly built, making it a good choice for a surveillance system.
It can be connected either to a wired Ethernet or a WiFi wireless network, comes with a high quality colour sensor and built-in microphone and has an excellent pan and tilt function that can be controlled from the web interface or from a supplied mini infrared remote control.
The camera can also be set up remotely in autopan or patrol modes to scan a room. The bundled software lets you archive streaming video to your hard drive, search and playback stored video, monitor as many as 16 cameras on a single screen and set up motion detection to trigger automatic recording or e-mail alert notification.
D-Link has clearly gone to a great deal of trouble to make the set-up procedure as simple as possible, using an easy on-screen guide.
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Equally importantly, the company provides free round-the-clock support for users who run into problems.
The only hiccup I encountered during set-up - and it is one that others may also experience - is that my cable-based Internet Service Provider blocks the port that is used by default to view and control the camera remotely. This means you have to tinker with the settings - something that turned out to be easy once the problem had been identified.
Overall, the DCS-5300W is an impressive product that delivers high-quality video and sound over the internet and shows just how far network cameras have come in the past few years.
从Webcam看世界
我肯定有窥探癖。EarthCam(
www.earthcam.com)、Webcam Central(
www.camcentral.com)和Camscape(
www.camscape.com)都是我最喜欢的网站，这三个站点提供了许多链接，可看到全球各地大量的网络摄像机。
我能观赏莫斯科红场的日出，观看密歇根州一群木工蚁来回忙碌，还能看到伦敦特拉法尔加广场的交通场景。网络摄像已成为互联网上的一道风景线，提供信息、娱乐，有时还能给人启迪。正如EarthCam网站所宣称的，它能让"全世界的人观赏世界"。
但在不远的过去，网络摄像机(webcam)（还被称作network cameras）大多还非常笨重、昂贵，而且难以安装。而近几年中，随着为消费者和小企业市场设计的新一代网络摄像机的出现，这种情况已经改变。
新一代网络摄像机体积小、价格合理、设计周到，让缺乏或者根本没有网络经验的人都能自己安装。它们日益成为旨在与WiFi 802.11b网络整合的无线装置，而且能通过本地网络监控，或者在世界任何地方通过标准网络浏览器在互联网上作远程监控。
它们能发挥基本的保安功能，如在户主工作或外出度假时监视房屋、监视办公室，以防外人闯入，或照看孩子或宠物。
我决定看看三家厂商推出的最新款网络摄像机。这三家厂商分别是：网络视频摄像机市场先驱瑞典的Axis Communications(
www.axis.com)、Veo(
www.veo.com)，以及家庭网络市场专营公司D-Link(
www.dlink.com)。
所有我尝试的这些网络摄像机都是专门为家庭或小型办公室以太网环境设计的，而且与路由器设备和高速宽带互联网接入配合使用效果最佳。
大多数现代路由器都有四个或以上标准以太网端口，并使用一项名为动态主机配置协议(DCHP)的技术，我正在使用的这款D-Link DL-624 I无线路由器就是这样。动态主机配置协议为网上每个设备自动分配唯一的网络地址，有了这种功能，设置包括网络摄像机在内的任何网络设备就变得简单多了。
然而我发现，当你碰到意外问题时，比如要设法通过一个安全防火墙，这些设备还能帮你联络技术专家。
Axis 205售价约200美元，号称是世上最小的网络摄像机。这款产品便于握持，为室内专用型。摄像机固定在一个小架子上，使用时通过标准以太网电缆接入家庭或小型办公网络，但有点奇怪的是，该产品出售时不提供电缆。
我发现Axis 205很容易安装，只需将摄像机连接到网络上，插上电源适配器，然后等摄像机前部的状态指示灯变绿就行。指示灯变绿就表明，摄像机已成功地从DHCP服务器上接收到了一个IP地址。
接着，你就被带去参观AxisCam的主页，然后按照指令完成安装。作为安装过程的一部分，摄像机会收到自己的网络域名，然后你就用这个域名通过摄像机远程观看影像。对我来说，安装过程完美无缺，这款摄像机能与包括Windows、Mac OS和Linux在内的大多数系统兼容。
一旦安装完毕，Axis 205就能以每秒高达30帧的速度、最高为640x480像素的三种不同分辨率，传送理想画面质量的影像。Axis 205价格低，安装简单，如果你想同时安装多个室内网络摄像机，这是个不错的选择。
如果你生活在美国或亚洲，多花100美元就能得到Veo的Wireless Observer。这是一款体积稍大的无线室内设备，有摇摄和俯仰拍摄功能。（Veo也出售标准以太网连线版本，价格200美元。）
Wireless Observer内置WiFi连接，因此很容易完成安装，当然，前提是你有现成的无线网络。与Axis一样，在我的本地网络上，Veo的设备以每秒30帧的速度传送分辨率为640x480像素的影像，并通过其基于网络的浏览网页提供有限的摇摄和俯仰拍摄功能。
该设备的安装指南基本够用，涉及使用者可能遇到的多数（但可能不是全部）问题。然而，摄像机的设计中有些巧妙之处，比如可在一个小液晶屏上显示其IP地址。与摄像机搭配销售的软件安装好后，用户就能自动发送带有快照图像的电子邮件，同时观看多个摄像机传来的画面，并抓拍快照和影像，传给联网的个人电脑。
D-Link SecuriCam DCS-5300W网络摄像机是D-Link网络摄像机系列中的最新产品，在美售价约300美元，欧洲还买不到。在我评论的三款摄像机中，DCS-5300功能最多，给人印象最深，造得最结实，使之成为监视系统的良好选择。
该设备可以接入有线以太网或WiFi无线网络，设备上有个高品质的彩色传感器，且内置麦克风，并具有出色的摇摄和俯仰拍摄功能，可在网络界面上调控，还可用该产品配备的袖珍红外线遥控器来控制。
这款摄像机还能远程设置成"自动摇镜头"或"巡逻"模式，来回扫视一个房间。利用与产品捆绑销售的软件，你就能把影像流存到你的硬盘里、搜索并回放储存的影像、在一个屏幕上监控多达16台摄像机，以及设定"动作感应"(motion detection)来启动自动录像或电子邮件提醒功能。
显然，D-Link已想方设法让该设备的安装步骤尽量简单：它提供了一种方便的屏上指南。
同样重要的是，该公司提供24小时免费技术支持，为用户解决他们碰到的问题。
我在安装这款摄像机时只碰到一个障碍，其他人可能也会碰上，那就是我的有线互联网服务供应商把一个端口封住了，而这个端口是观看摄像过程或远程控制该摄像机的默认端口。这样一来，你就不得不试着调整网络设置，而最终看来，一旦知道问题出在这里，解决起来还是很容易的。
总而言之，DCS-5300W是一款让人动心的产品，能通过互联网传送高品质的影像和声音，同时显示，在短短几年中，网络摄像机发展得有多快。
