My search for a wireless lapel or lavelier mic has been continuing and today I've had a bit of a break through.
First of all I found this product from Sony
ECM-AW3 Bluetooth® wireless microphone for recording devices with microphone in jacks
Unfortunately its discontinued but a web search showed there still seems to be stock around.
In looking around youtube for reviews of the Sony mics I came across this youtube video
Well that had me thinking. I knew it was possible to record sound onto an ipod and I've got plenty of old blackberry headsets kicking around I just needed to find out how to make it work.
Well it turns out it couldnt be simpler. The software is built into the newer generation of ipods. I have a 5th Generation Classic 160Gb and one of the new 6th Generation 16Gb Nano's with the touch screen.
I 've taken an old blackberry headset and chopped off the headphones. When I plu it into either of the ipods the "Voice Memo" option appears and its easy as an easy thing. The touch screen Nano even has a nice neat sound level indicator. With the Classic your flying blind really.
Sound recording quality is pretty damn good at 16-bit at 44kHz and only really limited by the quality of the mic.
So from what I can see (I havent tested yet) these are my conclusions
The Sony option offers a pretty cost effective and simple way of recording into the camera. Because its straight into the camera there is a lot less post production faff. It will also be pretty easy to check for quality. With a bit of messing around its possible to rig monitor headphones up to the camera so its checked as you go along plus the sound will also be checked when video is played back in camera.
The actual mic unit is pretty big and would be difficult to conceal and the battery life is limited.
The sound in the Canon cameras is seriously affected by the Automatic Gain Control (means you have a significant hiss as when the sound levels are low as the camera automatically turns up the recording 'volume'). If you have the option its definitely worth installing Magic Lantern to solve this.
The Ipod and chopped mobile phone headset is the ghetto option. Its costing me nothing to try. I've done some initial audio tests and the sound quality seems pretty good to my ignorant ears.
Its an incredibly flexible system, there are no distance to camera limits and the number of sound tracks you could record is limited to the number of ipods and mics you could scrounge. The input into the ipod needs to be via the three way 3.5mm headset jack as used on many mobile phones inc Blackberry and Iphone. With a trip to Maplins and some soldering iron nouse I'm sure it wouldnt be hard to knock up a couple of adaptors for any mic to be plugged into an ipod.
This system doesnt require sound input jacks into the camera and side steps the problems with the AGC in the Canon cameras
To make the sound useable needs some discipline though. Probably worth using a clapper board and probably worth using a note book. I'd worry about the ipods turning themselves off inbetween shots so you'd need to be very disciplined and organised to make it work.
Post production is also more complicated as you need to sync the sound recordings to the video. To do this you need software that allows multiple tracks to be added. (Wax is free and does the job pretty well once your used to it)
I'll sort out a test video of the ghetto system and post it soon