- A few sheets of black construction paper or posterboard at least 11x17"(medium thickness) - easy to cut, but rigid enough to not tear easily
- X-acto knife
- Electrical Tape
- Draw a circular template wide enough to fit over the front of your lens. An easy way to do this is lie the lens — lens-side down and with lenscap on — on the paper. Get a pencil or pen and trace around the lens with the pen abutting the side of the lens.
- Using a T-square or ruler find the center of that template by drawing a cross-hair
- Make marks 3/8" from the center of the template. Then connect the marks to create a 3/4" circle.
- Cut out the template and the 3/4" hole in the middle.
- Now you'll need to make the side of the lens filter. Calculate the circumference of your lens: remember pi (3.14) * diameter? Take that number and add a 1/2" or so (for overlap) — this will be the length of your strip.
Now draw a 2" wide rectangular strip of the calculated length onto the paper. Cut that strip out and set aside.
- Take the front part of your lens filter and wrap the rectangular strip around it. Attach the two elements together with some tape for a secure fit.
- Add two velcro strips on top and bottom of the center hole — we used velcro tabs and cut them in half. Your bokeh filter is done, and now its time to make some custom shapes.
- We'll make some interchangeable filters by cutting out some more circles from our template paper. Let's make one by simply cutting out a circle that is a bit smaller than your lens filter but larger than the 3/4" hole - a drinking glass usually works well as a guide.
- Now find that center point and cut out whatever shape you want your bokeh to take. Just try to keep the total width within about a 1/2".
Now you can make several interchangeable filters and swap them out on the fly. The filter works best at night when focusing on something very close, with bright scattered light in the background — think christmas lights. Here's some more shots we took with it.
Hope you enjoy this easy, cheap, and fun DIY. Let us know what shapes you make with it.