The DJI O3 and O4 air units are a huge step up from analog video, with users enjoying more detailed, cleaner video in their goggles. That being said, the cameras are expensive, and a lens protector is crucial to helping avoid damaging or breaking your camera in a crash.
ND filters
Because the video from an O4 or O3 is such high quality, many people are finding that they do not feel the need to use a GoPro or other action camera - they just use the video straight from the air unit - it's "good enough". And to make the best of the video that comes out of it, we want footage that is free of jello and vibration, and has silky smooth motion. And for this, we need ND filters.
O4/O3 Mounting System
Luckily the DJI O3 and O4 Pro cameras have a built-in method of mounting lens protectors and ND filters - inside the lens hood there is a little indent in the plastic at the top and bottom. Filters and lens protectors can "plug into" this indent to stay seated inside the lens hood.
Unfortunately, this mounting system is not perfect. There are some serious flaws in DJI's design:
- Because the lens hood is not very wide, any filter or protector installed will have some degree of vignetting (dark corners) in the video when using ulta-wide mode because it blocks light on the very edges. Luckily though most people use regular wide more, so it is a non-issue for most.
- Because the indents are so small and shallow, filters must fit very tightly to stay seated - this is especially important when using them in FPV drones that crash. Because they have to fit tight, it means that they can be difficult to put in and remove.
- Also because the indents are so shallow and because filters and lens protectors have to fit so tight, installing and removing them will gradually wear away the plastic in the lens hood over time - which makes them fit less snugly, to the point where they can fall out much more easily.
If you swap out filters enough, you will eventually start to experience the loosening of the mounting system described above.
So, how can we avoid filters and lens protectors falling out of an O3 or O4?
Here are 3 things that you can do that will either reduce or eliminate losing your filters and lens protectors from your air unit:
A) Put them on and remove them correctly!
If you install them onto your camera by just pushing them on, you are maximizing the damage to the plastic on your camera.
The best way to install a filter or lens protector into an air unit camera is to first install one side (for example the bottom), then press down firmly so that is bends the plastic of the lens hood just a bit, and then push the top in.

