Unfortunately there are aren’t any Fishsys lens for SX20. There are 58mm Fisheye convertors which you can fix your Canon SX20 camera with a 58mm filter adapter but better careful about this. These Ultra zoom compact cameras are not made for mounting external lenses so might effect the motor of lens barrel in bad way.
There are 58mm Fisheye Lens for Canon SX20 camera in Amazon. Don’t expect same quality you get from a real Fisheye lens but these are good for play around with you SX20 camera. My only worry is the weight of these Fisheye lens.








