Hacking Full-size Camera Panoramas to Work in Facebook
UDPATE 2016-08-01: It turns out there is a very technical article on Facebook written by Eric Cheng, the Head of Immersive Imaging at Facebook describing this very thing. His article is quite technical (and also includes info on spherical panoramas) and while it does mostly mirror my findings, it's a long-winded way of describing what I ultimately explain how to do very simply. So if you're looking for a how-to, jump to the end of this article and follow the few simple steps!
Facebook's new panorama feature is pretty cool. If you haven't seen it, a pano uploaded to Facebook shows as a scene you can not only pan around with your finger, but actually tilt and turn your phone to explore. Neat!
I tried uploading a panoramic I'd created in Lightroom, but it only showed as an ultra-wide photo in Facebook, and not as an explorable panorama. The general consensus among my friends on Facebook was that only smartphone-shot panos would load in Facebook properly. To this I thought, “there must be a way around it!”. I figured what was needed was to trick Facebook into believing that a photo came from the iPhone, even if it didn't.
Here's the photo I'm working with… it was created with 52 photos shot on a Panasonic LUMIX GX85, adding up to 29,919 × 4,582 pixels, which comes to 137 Megapixels.
Facebook could be sniffing the file any number of ways… EXIF data stating camera make or model, resolution, pixel height, and so-on. So I set out to “crack the code”, as it were!
I'm writing this post as I experiment… it's the easiest way to keep track. So it's potentially quite long… and really only relevant to the curious. The end result can be found at the end of the post!
Knowing if a panoramic will display properly in Facebook
First off let's look at how you know if a photo will work as a facebook pano or not. When you load a photo in the iPhone app, you'll first see a little globe icon on the thumbnail telling you that it's a pano:
Once loaded, you'll again see this globe icon on the wide image. If you don't see the globe at this point, that means that while originally Facebook saw it as a panoramic photo, now that it's loaded, it's not going to display as one.
Now that we know how to tell if a photo will work or not, it's time to make a photo that won't work, work!
(Head's up… this is gonna take a while…)