Big Crystal Ball Fisheye for Canon PowerShot ELPH180

It's fairly obvious that a crystal ball produces a fisheye view when you look into it... so why not have a camera look into it? That's what this thing does: mount a BIG crystal ball at an appropriate distance in front of a Canon PowerShot ELPH180 (or similar camera).

Clear crystal balls are very common on eBay. In [an earlier design](https://www.thingiverse.com/thing:3125412) I made a mount for a 30mm diameter ball, but the image quality was very poor. So, perhaps a bigger ball will do bette