Tie-clips and Booms
Adding an external, camera-mounted microphone can make a decent improvement to your sound quality, particularly a directional one like the Rode. But if you really want to cut out background noise - for example when conducting interviews - you will need to use microphones placed much closer to your subjects than on the camera body itself.
There are a number of ways of achieving this. For journalistic interviews, where it doesn't matter if the microphone can be seen onscreen, a simple handheld mic will do the job. You can even use your external camcorder mic - just remove the camera mount and add a longer cable. With the microphone much closer to the audio source, background noise will be significantly quieter.
If you want your microphone to be more discreet, you will need to invest in a tie-clip (aka Lavaliere) version. You can pick one up for less than Â£40, such as the Audio-Technica AT829CW. Sennheiser's ME2 is only about Â£20 more and is regularly used by professional videomakers. Alternatively, you can attach your microphone to a boom and position it just outside the camera frame, pointing at your subjects. Stands start at under Â£30. If your subjects are moving, you can remove the boom and use it manually - although this means having an extra person ensuring the microphone is pointing the right way at all times, but remains out of the frame.
However, in any situation where you use a long audio cable to your camcorder, you will need to be wary of the cable itself introducing noise, particularly from the mains supply. You can avoid this by using your camcorders on battery, rather than the mains. But you will still need to contend with lengthy cables.
The alternative to this is to go wireless, although this doesn't come cheap. You can pick up entry-level wireless microphones for as little as Â£60. But these aren't best suited for use with camcorders, as the receiver is mains powered. Probably the best kit of all is Sennheiser's Evolution Wireless EW112P G2, which costs around Â£350. It includes bodypack transmitters and receivers, plus the ME2 lapel microphone. It also supports XLR connections for attachment to professional camcorders - which brings us to our final section.