Review time!
Rode VideoMic Pro. Well-built, decent value for money (£150)
if the device you're plugging into can utilise it properly.
Unfortunately, the 7D is not such a device.
The AGC (Auto Gain Control) is a real pain, and there has not been a firmware hack (Magic Lantern) created for the 7D like there has for the 5DMkII. Although saying that, really don't like the idea of third party firmwares anyway personally. The AGC means that during periods of low input the AGC ramps up the mic and basically adds a bucket load of hiss to the audio track.
So, with no firmware hack, the only solution from what I can tell is to use a nasty workaround which is to use a ghetto cable that you have to make yourself to feed a 19khz signal into one of the stereo channels from an mp3 player (the other channel would be the mic input). This signal tells the AGC not to kick in then you can delete the 19khz channel in post leaving a clean signal.
IF you can be bothered to do this, then the RVMP is pretty damn good. As it stands if you want to plug and play like most of the world would want to do, these aftermarket mics only add a slight improvement leaving an audio track which is far from professional.
Why Canon haven't listened to their customers and released a firmware where you can disable the AGC is completely and utterly beyond me.
All in all, I wouldn't bother. if you want a pro sound record separately with a Zoom H4N or whatever and sync in post.
EDIT: here you go, I've started a blog and this was my first post:
External Mics for Canon DSLRs
(Haven't styled the blog much yet or even added a decent header image but I'll be doing it all soon... either way, the blog post content is finished
)
