Thanks for that, we do have multiple back up solutions I just didn't know how much space hd video would take up
I'm a fan of small cards it forces you to be more organised and avoids the annoying situation of tidying up cards when you have no idea which shots etc have been copied off and backed up and which haven't!
I feel small but numerous cards are also safer in case of data loss, since if you just use one single large card for everything, in the event that the card fails, everything is gone. All your eggs in one basket and all that.