How to Laser Cut Shaped Bokeh Filters

by jtsubota in Circuits > Cameras

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How to Laser Cut Shaped Bokeh Filters

photography ideas.jpg
Don’t own a laser cutter?  Me neither.  But I’m saving up to buy one.

In the meantime I’ve been outsourcing all my lasercutting projects like these custom bokeh filters.

The above video tutorial will explain everything you need to know to create your own lasercut shaped bokeh filters.

Step 1: Materials
Adobe Illustrator - Other vector-based drawing programs can also be used such as CorelDRAW or Inkscape.  Inkscape is a free program that is downloadable here.
DSLR - Digital Single Lens Reflex Camera
Prime Lens - Lenses with lower f-stops or larger apertures are generally better.  A prime lens, for those of you that don’t know, is a lens that does not zoom.  Since the lens lacks the mechanisms required to zoom, it’s possible for the aperture to be much larger ... which allows for a narrower depth of field and more pronounced bokeh.

If you have no idea what I’m talking about and need to know what the best lens is, just go buy the 50 mm 1.8 lens (aka the nifty fifty) for $100.

Step 2: Download Laser Cutting Templates
Illustrator, CorelDRAW, and InkScape templates can be downloaded from Ponoko's website.

Step 3: Figure out filter size
If your lens cap is marked as 58 mm, then your filter diameter will be approximately 0.5mm smaller than the lens cap size.  The diameter that seems to work best for me is 57.477 mm

Step 4: Figure out 60% of maximum aperture
The maximum aperture of your lens is determined by dividing the focal length by the lowest f-stop.  Then multiply the maximum aperture by 0.6.  For example:
The 50 mm 1.8 lens has a maximum aperture of 50 mm /1.8= 27.8 mm
Multiply this number by 0.6 and you’ll get 16.7 mm

Step 5: Create two concentric circles
Using your drawing program, create two concentric circles.
The outer circle is the filter diameter size.
The inner circle is 60% the maximum aperture of the lens.

Step 6: Create your design
Your bokeh design must be smaller than the inner circle (60% of the maximum aperture.)  The design must also follow all the requirements listed on Ponoko’s templates.  I used Adobe Illustrator which meant that all my cutlines are pure blue and had a stroke width of 0.01 mm.

Step 7: Export and upload your design
Once your design is done, follow Ponoko’s guide on how to export and upload your file.  Be sure to follow the directions exactly.  See the links in the above step.  If you don’t follow the directions exactly, Ponoko will not be able to make your image!  For an Illustrator file, it must be saved as an Illustrator 8 EPS file with all options turned off.  
 

Step 8: Shoot and have fun with your cool bokeh effects!
If you have any more creative bokeh photography ideas, please let me know!  I’ll be happy to make some more designs if you have any cool photo bokeh ideas!  And if I win the Epilog contest, I'll be well on my way to starting my own in-home company making these filters!