Love, Life And Everything Else 

The Rise Of DSLR
DSLR (Digital Single Lens Reflex) cameras look set to eat into the market for camcorders.  The latest DLSR cameras all can record videos. It is also much cheaper to buy a DSLR camera than a fully function camcorder, especially if you are just shooting the occasional videos. So is it better to buy a DSLR camera instead of a camcorder?
Many DSLR cameras like the Canon D550, Nikon D7000, Nikon D5100 and the Sony A55V, all feature decent video recording capability.  Of the lot, Canon D550 is the best for video recording as the sensor can last the longest before it automatically shut down. It can record 29 minutes of video.  The Nikon D7000 is good for 20 minutes of video recording.  All DSLR has a safety feature to prevent over heating of the sensor.  Once the temperature limit is reached, the camera will stop the video recording and shut down.  You must then wait for the sensor to cool down before you can operate the camera again.The Sony A33/ A55 can also record 29 minutes of video but only if the built-in sensor image stabiliser is switched off. If not, the video recording is good for 9 minutes only.
Video recording is a drain on the battery for both DSLR camera and camcorders. Of course, battery life also depends on the format of video recording i.e. MP4 or AVCHD. So shooting extended video on DLSR may be challenging. You can shoot consecutive short clips as the sensor can cool down quite quickly. So it is often a matter of switching on the camera again after the automatic shut down.  However, the battery is not intended for shooting video for long duration.
So although DSLR offers very good video recording capability, a full function camcorder is probably more suitable for recording long videos.