This instructable shows how to make your own fisheye lens really quickly, in simple steps
If you are into serious photography, you should think of buying a proper fisheye lens, as this one gives low quality photos compared to professional lenses (but it costs much less!)
This instructable costed me under $15 and 10 minutes of handy work.
You will need:
Tape (quite a lot), a peephole and a lens hood.
The door peephole, should have the widest angle possible (the one in this video is a 290º door peephole, bought on eBay: http://www.ebay.com/itm/New-290-Degree-Peep-hole-...
Be careful with scams that claim they have 360º view: to this date, I did not find any that would give such viewing angle in reality. But if you find one, let me know!
Step 1: Step 1: Tape, Tape, Tape
This process is quite simple, just start taping around the peephole, getting a thick layer of tape. Using tape eases the process of calculating where is the middle point of the peephole, as this is the most difficult step.
Start taping around the peephole until it fits tightly into the lens hood. I used sports tape in the end because it is softer, so it will adjust better to the lens hood. Be careful with the position of the peephole: if it is too much into the lens hood, you will get less viewing angle because the lens hood will block the view!! You can of course shave the hood if you have a spare one: See the video for the full process!
Step 2: Result
Attach the peephole to the lens hood and use a lens with around 50mm focal length (a kit lens does the trick). As you can see in the sample photo, there is an obvious loss of sharpness in the fisheye compared to the normal one, but it can be really useful.
The normal photo was shot with 18mm (widest angle for kit lens), the fisheye one at 55mm (zoom for the same lens). I could have used other lenses, but I thought that it would be nice to show the effect with the same lens. Although there is a loss in photo quality, it helps to grasp more of the area, and it's almost for free!