I love Instagram. It's a great platform for both sharing your photos and also seeing what some of your favorite photographers are up to.
Although it was built for photography, IG can also handle 15 seconds of video in the Quicktime format with H.264 compression. If I already lost you, hang in there, I promise it won't get too complicated.
There are a few basic steps you have to take to get your timelapse clips on IG:
Step 1 - Create your timelapse
I will assume you already have a timelapse prepared, either as a standalone file (I render all of mine as AVIs with the CineForm Codec). If not, you can use your image sequence in PP or AE. If you're looking for directions in Final Cut, you're gonna have to look elsewhere because I'm the last photographer on Earth that uses s PC.
Step 2 - Create a Comp / Sequence in After Effects or Premiere (Respectively)
I use AE for this, since it's simpler**. Start by creating a 1:1 composition with a size of 640x640, and a frame rate of 24 fps (or whatever frame rate your intermediate file is in). Then, import the timelapse files you want to upload to IG into your project. Drag them, one at a time, to the Comp, and scale accordingly. You can keyframe position and scale to taste if you would like to move or zoom through your footage.
Ensure your clip has less than 15 seconds worth of data on the timeline.
Add music if you want, but remember, make sure you have the rights to use it because professionals deserve to be paid for the use of their work!
Step 3 - Render out the Video
Add your composition to the render queue, and then open up the settings dialog. I have found that setting the Quicktime format with the H.264 codec to 100% quality and using a high bitrate of 24 MB/sec produces a smooth video that IG will handle no problem.
Step 4 - Upload to Dropbox / Download to your Phone
Copy your rendered TL clip to a folder you have prepared on Drobox, and then wait for it to upload. Once it has, open the Dropbox app on your phone, and then view the clip. Hit the "share" button, and save it to your phone's local storage.
Lastly, open IG and browse to the clip, and upload it. Add filters if you want, and then post away as you normally would with a photo. As far as I know, IG uploading apps such as the excellent Latergram do not allow for video uploads, so get those thumbs warmed up and start typing on your phone.
And that's it. You can view my work on my Instagram feed here.
*Step 6 Above is entirely optional and up to you to achieve this milestone
** No one in the history of the world has ever said that about Adobe After Effects before