Trying to get rid of the shutter effect (jello) with ND filters

Yes, I´m still trying to get rid of jello! It seems that shooting with the GoPro under too bright conditions, it uses a very fast shutter speed which records all the tiny high-frequency vibrations from your motors, props, etc., and causes this rolling shutter effect, or jello.

Fixing this is still a priority in my To-Do list, as I have to eliminate lot´s of shots that could be used perfectly in the final footage because of the jello. I will try to reduce part of it (or all If I´m lucky!) using a neutral density filter to reduce the shutter speed but letting through enough light for a clear picture.

There are some already made filters for the GoPro but are a bit expensive, and who knows if they are going to solve my problem... so I prefer to go first for a DIY solution and see what happens.

This is the solution I have come up with, for under $5:

• Lens protector ($4.57)
• A piece of cardboard (used to avoid the shadow of the propellers on the lens)
• A thin cord
• A neutral Density filter (I have used a .9, that reduces light 3 stops)
• Glue

Steps:

1. Cut the cardboard with the shape of a trapezium. 

• Long side: 4.5cm
• Short side: 2.5cm
• Height: 2.5cm

1. Cut the plastic base of the lens protector so it fits the holder of the GoPro Gimbal. I guess you can use it without this holder to reduce weight too...
2. Glue the lens protector to the holder. I highly recommend to always use the lens protector (with or without filter). I´ve commited the mistake of not using it and I´ve damaged the lens :( (see picture below).
3. Cut a circle of 3cm of diameter from a piece of ND filter. You can either buy it, or ask for a filter sample bock at a photography store. The samples have the perfect fit for the GoPro and you have lots of them to try!
4. Glue the thin cord to the border of the filter, in order of being able to take it out from the lens protector. This is due to the holder of the gimbal, that has a smaller diameter than the protector itself.
5. Insert the filter into the lens protector.
6. Glue the cardboard (the visor) over the lens protector, and use the WiFi preview of the GoPro to check if you need to cut a bit more the visor in order to not appear on the shot (I had to do it to avoid it using the wide FOV).

So let´s fly and see what happens!