You wanted that cinematic film look with your drone so you picked up some ND filters. You didn’t want to miss out on a good shot so you bought a set of filters from ND4 to ND64.
Now that you have them, how do you pick which one to use?
Why is it that some people use ND16 most of the time, but others have to use an ND32 to get good footage?
What do those numbers even mean?
Let’s walk through picking the right ND filter in a simple non-technical but quickstart kind of way…
First, let’s tackle the 1 stop reduction, 2 stop reduction descriptions. All you have to remember is that 1 stop of reduction means to reduce the shutter speed by one half. For example, going from 1/120 to 1/60.
Second, ND16 allows you to decrease shutter speed to 1/16 of the current shutter speed (speed without an ND filter). It reduces the shutter speed twice as much as an ND8 because the ND8 decreases the shutter speed 1/8.
Third, for brighter days, use a darker ND filter. The higher the number the darker the filter.
How do we apply this to our drone footage?
Rather than have you figure out the math, here is a quick reference to help you get to a shutter speed of 50 or 60 for cinematic footage at 24 or 30 fps respectively.
Our formula will be ND Filter + Current Shutter Speed = New Shutter Speed.
Start by setting your camera to Manual and ISO to 100.
Next, try and set your shutter speed to twice your frame rate.
If you cannot reduce the shutter speed to twice the frame rate, find the combination below that is closest to your current shutter speed and desired shutter speed.
Then give the corresponding ND filter a try.
For 1/60 Shutter Speed:
ND64 + 3840 = 60
ND32 + 1920 = 60
ND16 + 960 = 60
ND8 + 480 = 60
ND4 + 240 = 60
For 1/50 Shutter Speed:
ND64 + 3200 = 50
ND32 + 1600 = 50
ND16 + 800 = 50
ND8 + 400 = 50
ND4 + 200 = 50
What ND filter do you use most often? Let us know in the comments below.