ADI has added a post on RAID Drive Setups for video surveillance.
ADI discusses RAID1 and RAID5, though recommends RAID1:
"For security installation companies who want a sure method of automatic backup it would appear that the RAID 1 setup is the way to go."
ADI says that RAID5:
"Studies have indicated that the reconstruction of data using RAID 5 configurations can be a hit or miss proposition."
RAID6 is not brought up by ADI at all, though we've talked about its role: Advantages of RAID6 over RAID5 For Video Surveillance and What Are The Alternatives If RAID5 Is Dead And RAID6 Is Dying?