Bird's Eye Camera Stand

thingiverse

A panoramic lens is a close cousin to a fisheye lens, employing a reflective optic to deliver a full 360-degree view. This thing is a stand designed to enable panoramic imaging by holding an $80 Canon PowerShot ELPH115IS centered over a reflecting element - a standard silvered glass ornament like the kind you can find around Christmas for $0.50. Since the ELPH115IS can be programmed using CHDK, the rig can be used as a self-contained device to capture everything happening in a room, and it's even possible to program the camera to "unwrap" the images into a more convenient format for viewing (e.g., cylindrical projection). Printer Settings Printer Brand: MakerGear Printer: M2 Rafts: No Supports: No Resolution: 0.25mm Infill: 5-25% Notes: Trivial print in PLA. I used black for the top and bottom, but natural clear for the connecting piece (which I also used a concentric fill pattern for); this makes the connecting piece less visually distracting in the 360-degree photos. Assembly The pieces come together in a rather straightforward manner, and can be either friction-fit or glued. However, the glass ornament requires some preparatory work. First, remove the metal top with the hanger. This leaves the top open. To make the unit more stable, I filled the ball with sand and then sealed it in place with a little cement/glue. I then realized that the ball had a thin plastic coating over it (probably to prevent shattering if it is dropped) - this coating degrades the reflected image a little, so I washed it off. Basically, under cool running water, the clear plastic coating simply slid off. Once dry, the ball is simply placed in the base with the top in the indentation shaped to hold it. Custom Section Unwarping the 360-degree image There are many software programs available that can unwarp the images into other projections. However, these balls are not mathematically precise, so reprojecting by a calibrated mapping works better than applying a simple function. In fall 2015, my students wrote CHDK code that performed this mapping in the camera, but I don't have a version in a nice, clean, releasable state yet... I'll post one when I get the chance.