Lomography has used and abused the fisheye concept as if it was the most mindblowing thing for any toy camera enthusiast. Use it on your Holga, or use it with a camera where you can take nothing but fisheye images.
Google for photography forums regarding fisheye lenses, and you’ll most likely get the same sentiment: ‘Cool! But I got bored after 5 shots 😕‘
I did go fisheye for a total of half-a-dozen shots, and I quit for the same got-bored-of-it reason. Of course I did it the Photoshop way, following in reverse the instructions posted here. Here are the shots I experimented on, from my Ilocos archives, angled at ‘130 degrees‘:
Click on the images to be redirected to a page with larger versions of the photos.