Introduction: How to Make a Fish Eye Lens for a Nikon D-90 Digital SLR for $16

I got the inspiration to do this Instructable while reading another Instructable that accomplished the same "fish-eye" effect using a PVC reduction pipe and an entry door viewer.

There was concern in the prior Instructable about around scratching the lens so I wanted to solve that problem in my easy to build fish eye lens as well as make a version which is easy to use, remove, etc.

I decided to modify the design by using an existing camera attachment which would easily mount to the camera and comes with most Nikon lenses.

The secret to my design is to use the lens shield as the attachment platform which allows the fish eye lens to be easily attached and removed from standard lenses while enabling a hands free experience.

The lens that I am using in the shot below is a Nikon 18-105mm VR lens. It came with the kit when I bought my camera.

Step 1: Prepare the Materials

The only thing that I had to buy was the door entry viewer which was $15 and some change so I rounded to $16.

In addition to that you will need:

- 1 Entry Door Viewer - The one shown below is a 160 degree large diameter version.
- 1 scrap particle board. 3" X 3" square
- 1 scrap particle board 1.5" X 1.5" square
- The old handy duct tape approx 10" in length
- Spare Lens shield - I never use one on this lens anyway so I'm using the one that came with it.

Step 2: Assembly Instructions

1. Place the lens shield on the 3"X3" square particle board to trace the circle diameter. (Make sure you use the end that is opposite of the camera connection.)

2. Find the center of the particle board and drill a 1" hole or as required by the instruction in your entry viewer.

3. Using the 1.5" X 1.5" square particle board piece, find the center and cut a 1" hole or as required by the instruction in your entry viewer.

4. Round off the corners of the 3" X 3" square to make a circle which matches the outside facing section of the lens shield.

5. Thread the entry viewer in the holes in both the small and the larger particle board pieces. (See 1st picture below)

6. Using the duct tape, carefully wrap a piece around both the large particle board piece and the lens shield to connect the two together. (See second picture below)

Step 3: Enjoy Your New Fish-eye Lens!

Have fun!

I built this in about 1/2 hour (most of the time was used in cutting out a circle. I used a drill press to lob of the corners with a drill since I didn't have a scroll or jig-saw handy.)

I think the pics came out pretty good for a quick project. :)

One note: Use the highest setting as you can on image quality and size since all of the shots below needed to be cropped significantly. (There is a lot of black space to crop out. See last photo for an example)