ND Filters and Exposure for Cinematic FPV
Symptoms / When to use this
The 180-degree shutter rule is the foundation of cinematic motion blur. ND filters let you apply it in bright conditions without overexposing. Getting this right is non-negotiable for professional-looking footage.
The 180-Degree Shutter Rule
For natural-looking motion blur, set your shutter speed to double your frame rate. Shooting 60fps? Set shutter to 1/120. Shooting 24fps? Set shutter to 1/50. Faster shutters produce an unnatural, staccato look.
The Problem in Bright Light
At 1/120s on a sunny day, even at minimum ISO and closed aperture, most action cameras will massively overexpose. ND filters solve this by reducing the amount of light reaching the sensor.
Choosing the Right ND
- ND8 (3-stop): Overcast UK days, early morning / late afternoon.
- ND16 (4-stop): Partly cloudy, standard UK summer light.
- ND32 (5-stop): Bright overcast or light cloud in full sun.
- ND64 (6-stop): Full direct sunlight at midday.
GoPro and DJI Specific Notes
The GoPro Hero 12 and DJI O3 Air Unit cameras both support Protune/D-Log M flat profiles. Shoot flat when possible and grade in post for maximum dynamic range retention. Use GoPro's Hyperlapse ND kit or the Freewell ND set for DJI cameras.
Checking Exposure
Use your camera's zebras or histogram rather than the LCD preview. LCD screens are not colour-accurate outdoors. Aim for a histogram that keeps highlights off the right wall.