Note: The 2nd generation ND8 Filters (sold since Sptember 2015) have a couple of design changes. They are seated properly if they all the way down touching the camera body.
A set of six ND8 (neutral density) filters for GoPro Hero 4 / Hero 3+ / Hero 3 cameras. The neutral density filter reduces the amount of light reaching the sensor and therefore increases exposure times without affecting the color of the image. The ND8 filter gives a 3 EV reduction in light, forcing the camera to use a slower shutter speed to get the same auto-exposure.
Why use a ND filter with GoPro cameras:
- Reduce or eliminate jello effect due to rolling shutter at high shutter speeds
- Create natural and smooth looking video due to motion blur
- Fitted for the Freedom360 mount V5.10 and newer
- 6 ND8 Filters with set screw, compatible with all Hero4, Hero3+ and Hero3 cameras
- Water-resistant Pelican Case with Microfoam insets, black
- Microfiber lens cleaner, black
For use with the Freedom360 Mount only. Not compatible with the F360 Explorer.
The exposure rates for each video frame on the GoPro cameras can vary from 1/8000s down to 1/24s, depending on the available light. This is independent of the chosen frame rate. GoPro cameras exhibit two effects: one is called the “jello-effect” or rolling shutter, caused by the top-down row-by-row readout of the sensor. At super high exposure rates (i.e. 1/2000s or shorter) the sensor readout gets “jumbled” (in addition to the rolling shutter), where parts of the frame get “distorted” (we haven’t found a good name for it yet, frame jitter may be a good one). The ND8 filters help avoiding those effects by forcing the camera to use a slower shutter speed. If, for example, one camera is exposing at 1/2000s, the ND8 filter will reduce the shutter speed to 1/250s (-3EV steps). This will not affect the overall exposure, which is still calculated by the camera-internal auto-exposure program. The ND filters will not affect the depth of field, but may add a more pleasing motion blur to fast moving objects (i.e. helicopter blades) or may help remove some of the frame-jitter described earlier.
It is up to the user to decide when and how many filters to use: one example would be using only 3 filters on 3 of the cameras pointing towards the sky (very bright), while the 3 cameras pointing towards the ground would film without ND filters. This will bring the effective exposure times of all 6 cameras to roughly the same values. The internal auto-exposure program will not be affected by this, and the brightness of each frame still needs to be adjusted in the video-stitching program. But all 6 cameras will have now similar exposure times, and the same amount of motion blur (if applicable), making the stitched result more pleasing.
Our custom ND8 filters sit close enough to the lens to not cause vignetting that affects your 360 video stitch:
Using the filters with the (older) Freedom360 V5.08
The new/current F360 V5.10 (early 2014 model) has modified braces to allow more clearance for the filters to be installed. If you have an older frame, contact us, or make a note in the order comments.