
If, like me, you took Steve Jobs at his word when he said iPhoto 6 onwards could support up to 250,000 images, and you've been piling them in ever since, you've probably got a very large iPhoto library.
Mine is currently sitting at 66,431 images and is 220GB on disk. It's so big that it convinced me to part with $1800 (Australian) to get the 512GB SSD Apple is making an option with the latest MacBook Pros. Obviously, at that price, it's a ludicrously overpriced option at $3.50/GB compared to smaller, cheaper SSDs, typically around $2.50/GB, or mechanical hard drives at about $0.14/GB, but I wanted to have a boot drive on which I could have my full iPhoto library so I could work with pictures much more quickly (and boy, does it make a big difference.)
However, one problem I've been seeking an answer to for years now is how to backup my photos off-site, in case a house fire takes out both my MacBook Pro and my Time Capsule backup. (Or, if my house was burgled and both the MacBook Pro and Time Capsule were stolen — which actually happened to a family member of mine.)
Simply dropping the iPhoto library into an online backup program like Carbonite or Mozy isn't viable, because uploading 200GB of data takes so long that it basically never completes — or the backup system gets so far behind that you'd be losing a lot of new photos if your house burned down.
The 'ideal' solution I had in mind was to do Time Machine backups constantly to my Time Capsule, as well as a fallback backup of downscaled resolution photos to an online backup location. I like Dropbox (my referral link included in that link) because it works so quietly and reliably in the background, but you could use any online backup service. Although some people might say that backing up the full resolution photos is important to them, to me, the most important thing is making sure those frozen memories don't get lost — and if I downscale them to fit within 1920x1920px, then I still have a high definition, albeit not camera-resolution, version of the photo.
I've now figured out how to do it! Full details after the jump.