DV camcorder advantages and disadvantages
At first you may think that using a DV camcorder is overkill for webcam broadcasting, and in some situations you're right. But DV camcorders also have a number of benefits that cheaper USB cameras don't have. Here a some of the more important advantages:
- A powerful zoom lens that allows for tight framing of subjects even from long distances.
- DV tape backup of the entire event that can be archived or repurposed.
- Advanced camera controls such as exposure compensation, white balance, special effects, and image stabalization.
- A FireWire interface for fast data transfer.
- An LCD flip-screen for precise framing when roaming with the camera.
- Quality components.
When covering an event, I like to keep the videotape running even though it's not necessary to do so while using the camcorder as a webcam. That way, I have a complete account of all the action that I can edit down to a movie, or refer to at a later time. Since most DV camcorders can only record 90 minutes per tape, you will have to carry a few extras for those long assignments.
The main disadvantage I've encountered is battery power. Camcorder batteries usually only last an hour or so, and they seem to die at the most inopportune times. It's true you can plug the unit into the wall for unlimited power, but then that sort of defeats the purpose of having a wireless webcam.
The best solution -- carry a couple extra batteries. Chances are that you'll need them to complete the shooting session.
DV camcorders have dropped considerable in price lately, and quality models can be purchased for around USD$500. Make sure you check compatibility with your laptop before spending any of your hard-earned cash.
I've been using an old Canon ZR for a couple years now, and it's a great webcam because it's so compact. I simply plug it into the Mac via a FireWire cable, and the image appears immediately on the CoolCam preview screen. It couldn't be easier to use.
Going wireless with your webcam
So far everything I've covered can be applied to just about any webcam set-up -- tethered or not. Now it's time to cut the umbilical cord and wander freely with your laptop and camera.
Once you have your webcam working on your PowerBook, unplug it from the wall and turn on AirPort. Depending on where your BaseStation is positioned, you'll have up to an 150-foot radius to roam for capturing images.
Does this mean you'll be wandering around with a laptop in one hand and a camera in the other while trying to follow the action? Well, I wouldn't recommend that. Instead, find a table, chair, or any stable surface to set your laptop on, and move around with the camcorder in hand. You should have at least a 6-foot FireWire cable to allow you to get the position you want.
This is where that LCD flip-screen comes in handy. With cheaper webcams, you have to use the computer monitor to see what the camera is recording. That's fine if you're tied to a stationary position. But now that you can roam, you don't want to have to keep referring to your laptop screen for image composition. Set the computer down and explore with the camera. You'll get better shots.
I always carry a portable tripod too. That way I can direct the camera at a scene without having to hold it the entire time. This also adds stability and sharpness to your images.
When you want to record in another area, just pick up your laptop and off you go. This technique works great at home events such as birthday parties, holidays, and other special gatherings. You can roam and record as long as your batteries last and you stay within network range.
But there are a few security issues you should be aware of. As long as you are using FTP over an 802.11b network, your user name and password can be intercepted by "black hats" who then have complete access to your web site.
You might think that since 802.11 only operates within a limited range, such as 150 feet, that you are safe within your apartment or office building. But that's false security because intruders can extend that range by using special antennas.
Is this likely when you're home? No, not really. But I recommend that you play it safe and make sure you have WEP (Wired Equivalent Privacy) enabled to help discourage intruders. Also, if you're using a Mac, it will display all 802.11 networks within range. If you turn on AirPort and see other networks listed, I would caution against using FTP for wireless uploading. Because if you can "see" those networks, they can see you too.
In the follow-up article, I'm going to outline how to set up a secure key and transmit via SCP. This is the way to go if you want to broadcast on a public network, such as at a conference that has a 802.11b network for its attendees.
The bottom line is to use common sense. Keep an eye out for other networks within range, watch for guys with big antennas, and always use WEP.