Know Your Needs
I've worked with memory and storage as part of my job for many years and I feel that I have a good handle on just how much space everything needs. I have 120,000 photos on my main PC and these have primary and secondary back-ups as well so I'm aware of the need for a large amount of space in some circumstances.
One of the first things I do when asking someone what they want from a PC, I always ask what they are going to use it for and then I can help to suggest how much storage they will need. of course, for a new system it's easy to then specify twice as much as you think they need to be on the safe side.
If we are going to store video - finished files or all the original footage - then we need to know what we are going to produce and roughly how quickly we are going to produce it. We really also need to be aware of how much we may need to spend to get the capacity we need in an economical manner.
Back of the Envelope
You get used to just using short-cuts when trying to work it all out. I always used to say that a JPEG photo was 5MB and that meant an easy calculation of 5Gb per thousand - useful for both buying a memory card for the camera or a hard drive to store 100,000 images (500GB). As digital images have increased in resolution, I have had to revise this rough estimate to more like 10MB per image. This actually makes the calculations easier though. 100,000 images is now 1000GB or 1TB.
Video is a bit more complicated. There are a number of different video resolutions and then a number of different ways to compress and store the video files and this all makes it a bit complicated to work out how much space you need. I'm always going to go with a higher than real-life estimate as well, just to be safe. The table below shows what I mean.
These figures are just a guide - your camera of choice will tell you what bit-rates it records at for the resolutions it supports. These are also figures for the latest H.264 or H.265 (for 4K) encoding systems and basic stereo sound. Less advanced compression systems will use up much more memory - anything up to ten times as much is possible.
So, How Much Space Do I Need?
Working at home on a fairly average computer, you're going to be realistically limited to working in 720P or 1080P for editing and other post-production work, so we'll use 1080P for our examples.
For our example, we're going to make an imaginary 10 minute video to upload onto social media at 1080P resolution. We are going to film some stuff then chop it down and put it back together into a great edited form that people will find engaging and watch right through.
Let's assume that we need to do three or four 'takes' for each scene of our project and that we often shoot for twice as long as the final cut requires. So, for 10 minutes of final footage, we have:-
4 Takes of everything X 20 Minutes of original time = 80 Minutes of footage
We'll also need a copy of the final video, but this is less than 1GB more, so we are still doing quite well. Remember though, this is for each 10 minute video that we produce and it can get a lot worse. Double the length of the video and you need double the space. become a perfectionist and you may need 20 or even more 'takes' to get a scene right.
Still these figures for 1080P video are manageable. Even a basic modern laptop will have 500GB or more of storage, enough for 50 or more 10 minute videos at this rate.
Just remember that for 4K video you have to triple these figures at least.
The Elephant In The Room
This is the bit that nobody likes to talk about and not enough people do anything about. I'm going to talk about it anyway, because I've been a victim and I've seen dozens if not hundreds of other victims.
If you value your work you need a backup.
If you really value your work you need two backups!
If you are using a desktop computer - as I am - then the first step is a simple one. Fit a second internal hard drive that is at least the size of your main one and set up the backup software that's built into Windows. It will do the job and you don't really need anything more. I actually take things to the next level and use Altaro Oops!Backup to do a little bit more for me.
As an added bonus, Oops!Backup allows me to specify another drive to make a clone of the main backup periodically. I therefore make a second backup every few days to an external USB drive.
Working in frontline PC support, I see failed drives on a weekly basis and the majority of people have no backup at all. Worse, many of them have a laptop that was supplied with a partitioned hard disk and they think they do have a backup when all they have is a copy on the same drive.
My first thought is that you should keep it all, forever! The reality is that you don't need to keep all of the original footage. Perhaps you don't need to keep any of it once you've uploaded the final video, but I would tend to take a cautious approach and keep the final edited video and the set of original clips that I used to make it. Throw away all the bad 'takes' because you'll never want to use them again for anything.
I'm not trying to put people off video, but it is important to be aware of the large amounts of data you will be generating. Honestly, get a camera and get started. Your present computer will have enough space for your first few videos and then you'll have a better idea of just how much data you are creating.
External drives are fine for storage or backup, just keep the working footage on the main drive of your computer until you've finished editing. A SSD (Solid-State Drive) is always a good idea - not just for video - but it's not essential provided you've got a bit of patience.
What Should I Keep?
My first thought is that you should keep it all, forever! The reality is that you don't need to keep all of the original footage. Perhaps you don't need to keep any of it once you've uploaded the final video, but I would tend to take a cautious approach and keep the final edited video and the set of original clips that I used to make it. Throw away all the bad 'takes' because you'll never want to use them again for anything.
Conclusions
I'm not trying to put people off video, but it is important to be aware of the large amounts of data you will be generating. Honestly, get a camera and get started. Your present computer will have enough space for your first few videos and then you'll have a better idea of just how much data you are creating.
External drives are fine for storage or backup, just keep the working footage on the main drive of your computer until you've finished editing. A SSD (Solid-State Drive) is always a good idea - not just for video - but it's not essential provided you've got a bit of patience.