Over at Instructables, user Banjomaster shows how to make a fisheye lens for his Nikon D90 for just $16, with the help of one of those wide-angle doorway peephole lenses. The image associated with this post is best viewed using a browser. It looks like a pretty simple mod, both in materials required and construction method: It only needs a couple pieces of particle board, the aforementioned peephole lens, the spare lens shield that came with his camera, and of course some duct tape. The only possible caveat: The replacement wide-angle lens is significantly smaller than the camera’s lens, so there’s a circle around all of the shots. On the other hand, it’s sort of cool; it makes everything look like you shot it through a hotel door.

Take a look at these trippy photos taken by Flickr user heiwa4126 using an ultra-wide fisheye lens . The technique used here is called stereographic projection —defined as a “mapping function that projects a sphere onto a plane.” [ Flickr via Boing Boing Gadgets ]

This fisheye lens from Japanese company Digital King is absurdly bulky and not at all practical. So we sort of love it. Attaching to the iPhone through a magnetic metal mount system (you’ll need to mod your iPhone with a metal sticker, it seems), this $100 “extremely high quality lens” stretches your iPhone’s field of view to epic proportions. If only the phone’s integrated camera were of a decent resolution, all this fuss may be worth something. Until that day comes, we’re just glad to have come across the product for another 30 seconds or so of amusement.