Video on Canon camera

[Dolby]

A friend asked to film their walk down the isle and speeches for them - I we can use either a 550D or 7D

- is either of these better than the other?
- are there limitations at all? I seem to remember something about focus?
- are there space limitations at all - or only governed by the card size?
- how much space does a video use? I suspect speeches are 15+ minutes which may be huge
- the mic reasonably sensitive?

I'll try these features shortly - just thought if someone has already used the video, I could get 1st hand experience.

Thanks

 

[Dolby]

Whoops - how do I delete this?