Bokeh is a photographing technique of blurring the background to get interesting effects from the lights in the background. Bokeh means appearance or feel of out of focus areas of an image. The highlights on the points of lights are usually circles or polygons depending on the blur. We can change the shapes of these highlights by building our own filters and using them over the camera lenses.
There are a lot of DIY articles describing how to make these filters with paper and tape. When I came across these articles, as an amateur trying to learn photography I tried to make the filter caps with paper securing it with tape and rubber band around the lens. But I got tired quickly with the experiments because they were not easy to use and not convenient to carry them outdoors. So I decided to build the filters using 3D printing. These plastic bokeh filters are convenient to carry around in a pouch and much easier to use. You will have them handy to use anywhere and you can have interesting shots at events like birthday parties, graduation, portraits, night life.
Step 1: What you need
2. Inkscape - SVG graphics editor
3. Alibre or your choice of software for making the 3D design.
4. Access to 3D printer
5. Christmas lights or candles or small points of lights.
Step 2: Overview
1. The bokeh filter lens cap. - Custom lens cap to insert the bokeh filter discs.
2. The bokeh filter discs - Circular discs with various shapes cut out .These discs are inserted in the filter lens cap.
Step 3: Bokeh filter shapes
Step 4: Design Bokeh filter caps
1. Measure the diameter of the front of the lens or the existing lens cap. The diameter of the Canon 50mm lens that I used was 52mm.
2. The size of the cap that we are going to design now will be 52mm and height 2mm.
3. Make a slot of 29mm diameter in the center of the cap.
4. Make provisions around the slot for inserting circular discs of 30mm diameter.
Step 5: Design the bokeh inserts
Step 6: 3D print
Step 7: Bokeh effect pictures
To test the lens,
1. You need some lights. I placed some christmas lights on a clothes drying rack and placed it a few feet away from the subject.
2. Keep the subject as close as possible and keep the subject in focus and make sure the lights are a blur.
3. Set the camera to the largest aperture.
4. Set the shooting mode to Av or Manual.
5. Fire away!!
You can experiment with different filter shapes, different distances of lights in the background, different types of point sources of light. You can create interesting visual background effects with various shapes of filters.
There is vignetting effect seen on the pictures. This could be due to bigger size of the circular discs. It would be better to make the designs much smaller. Also increasing the distance between the subject and the lights increases the quality of the blur.