Traditionally, time-lapse videos have been created with digital SLRs by taking still photos at set intervals and then processing the images in software to create a time-lapse video. The process can be relatively expensive and complicated as post processing is required. Unless you have a secure area to leave the camera, it may also mean monitoring the camera for long hours making long duration video impractical.
There is, however, an alternative method to creating beautiful time-lapse videos for under $100. Many action cameras have a time-lapse video feature allowing set images to be recorded at interval. The camera does the processing and creates the resulting video in camera. I used the SJCAM M10 available on ebay for under $100. I bought mine for $94. Beware of clones that sell for much less.
The camera has a wide 170 degree lens making sweeping cityscapes ideal. It’s small enough to mount easily and at under $100, it’s less painful if it does get stolen while filming. To create this San Francisco cityscape time-lapse, I mounted the camera on a clamp arm and attached an external battery pack. The camera’s 900mAh battery is not sufficient to record for a long duration so an external power source is necessary. Any high power pack will do. In my case, I used the Tylt Energi 2K which gave me about 28 hours of uninterrupted recording time.
I setup the camera on a rooftop in the late afternoon and set it for time-lapse with 10 seconds intervals. This results in 6 frames per minute. A 24 hour video will contain 8,640 frames (6 frames x 60 minutes x 24 hours). When played back at 30 frames per second, this will create a 4.8 minute video. (8,640 frames/30 frames)/60 seconds. Obviously, the video will have no sound because it is merely a rendering of many still images. I added a soundtrack from the Free Music Archives, a creative commons music resource.