DJI Phantom 3 Filter ring, holds ND filter gels on existing camera.

thingiverse

This Variable Density filter ring is designed specifically for the DJI Phantom 4. A 3D printed ring comes included to hold the ND filters in front of the existing lens on the Phantom. The ring is tailored to fit a 31mm diameter ND filter gel perfectly. Simply choose the desired ND filters to achieve your desired exposure, and stack them against the Phantom camera before installing the ring to secure them into place. Here is a YouTube video that demonstrates how to use these effectively https://youtu.be/0TbDhJvIUvA I am selling a pre-cut filter set for this system on eBay.http://www.ebay.com/itm/-/272214170861? It comes with: A 3-stop ND filter (3 stops darker) A 2-stop ND filter A 1-stop ND filter If you prefer to purchase a set that has already been made, you can do so at www.ditzco.com. The darkest filter is a 3-stop option. On an overcast day in high sun with a lot of brightness, this may be enough for 1080p/60. On a very bright day, 4-stops is usually necessary to achieve the same result on 1080P. This includes both the darkest (3-stops) and lightest filters (1-stop). Since the max frame rate in 4K is only 30fps, you will likely need to darken the image by one stop when going from 1080P to 4K. The shutter speed should always be twice as fast as the frame rate. For example: 1080p/60 = 1/120 second 4k/30 = 1/60 second The 3D printed ring and a single filter together weigh just 0.7 grams. Instructions If you print it using the default settings, the wider part of the ring will be the correct orientation. It was created with OnShape.com as the platform if you'd like to see more detailed information. If your filter ring does not fit after printing, simply adjust the size in your slicing software and try again. I have produced over 3,000 of these rings and every single one has fit perfectly on my MakerBot Gen3 clone using PolyMAX.