How to determine the # of hard drives needed
A question I get asked a lot is “How many hard drives do I need to hold the P2 card footage for my film?”
First you’ll need to determine the format and frame rate you’ll be shooting. An example is if you are shooting in the format DVCPRO HD and your frame rate is 720 23.98PN. N stands for native. Which technically, when you’re on set, it’s just called 720 24PN. If you have a 16GB card, at that format and that frame rate you’re going to get 40 minutes worth of footage on your card. Where if you want to stay in the DVCPRO HD format but switch from 720 24PN to a frame rate of 1080 24PN then the amount of time that you are going to capture footage wise on that card goes down to 16 minutes. So if you have a 32GB card you’re getting 32 minutes.
After determining your format and frame rate you can calculate the hard drive space needed for your footage.
A film script basic is that 1 page equals approximately 1 minute of screen time. A guess from that would tell you that for a 120 page script you will need 120GB of hard drive space if you were to film one shot of each scene and nothing extra. Now don’t run out and buy a 120GB hard drive because it’s not going to be enough.
Remember when filming there will be pre-roll and post-roll. Meaning each take footage is captured before “action” is called and after “cut” is called. Also, it’s rare that there will only be one take of a scene. Even if the first take is great, a second take is captured for safety. This additional captured footage is a factor as to why 120GB will not be enough.
But that’s not all. You also have to consider the safety of your footage.
If something happens to the only hard drive you downloaded your footage onto, you’ve most likely lost your movie and with that your money. So I always say that you need to put your footage on a minimum of two hard drives and I strongly recommend three. You may think three is overkill but believe me it’s not.
If on set you have three hard drives and one fails, you can still download to the other two without holding up the shooting process because the camera operator is waiting for an empty P2 card from you.
I suggest splitting up the hard drives at the end of the day. If you take both or all three of them in the same car and there is an accident. The hard drives may be damaged and you could loose your movie.
If you split up the hard drives by sending one home with the Producer, one with the Data Asset Manager, and one gets delivered to the editor, you’re movie has a much better chance of surviving the unforeseen. Also, that will usually ensure that you have two hard drives back on set the next morning. I say two because sometimes the drive that was delivered to the editor doesn’t return to set until later in the morning.
Okay, you may think that’s a whole lot of information but when it comes down to it, it's all doable. From my experience on set, a feature, very conservatively, filmed in the format of DVCPRO HD and with the frame rate of 720 24PN will produce just over 320GB of footage. So on the set of an average feature film you will need three hard drives that could hold more than 320GB of footage.
* The video version of this is at http://www.youtube.com/watch?v=Qy97KrLlUcg