ONID TECH

Why Your Action Camera Needs a Filter Kit

If you're serious about capturing stunning footage with your action camera, whether it's a GoPro, DJI Osmo Action, or Insta360, you've probably noticed that sometimes the results don't match what you saw with your own eyes. The sky might appear washed out, water reflections can be distracting, or fast-moving scenes might look jittery. This is where a camera filter kit becomes your secret weapon. These small, often magnetic or screw-on accessories can dramatically improve your video and photo quality by controlling light in ways your camera's software alone cannot.

At ONID TECH, we've seen countless creators transform their content simply by adding the right action camera filters to their setup. Whether you're shooting mountain biking, surfing, skiing, or travel vlogs, understanding how to use these tools will elevate your footage from amateur to professional-looking. This guide will break down the three most essential filter types: CPL, ND, and UV filters, explaining what they do, when to use them, and how to get the most from your filter set.

Breaking Down the Filter Trio: CPL, ND, and UV

Each filter in a standard kit serves a distinct purpose. Think of them as specialized tools for specific lighting and environmental challenges.

1. The CPL (Circular Polarizing) Filter: Taming Reflections & Boosting Colors

The CPL filter is arguably the most visually transformative filter you can attach to your action camera. Its primary job is to reduce reflections and glare from non-metallic surfaces like water, glass, and foliage. It works by only allowing light waves vibrating in a specific direction to pass through the lens.

When to use a CPL filter:

• Water Scenes: Shooting over lakes, oceans, or rivers? A CPL will cut through the surface glare, allowing you to see into the water. This is perfect for capturing underwater rocks while kayaking or marine life while snorkeling.
• Landscapes with Sky: It deepens blue skies and makes white clouds pop by reducing atmospheric haze, creating more dramatic and contrast-rich scenes.
• Through Windows: Minimize reflections when shooting from inside a vehicle or through a building's window.
• Foliage & Wet Surfaces: Removes the shiny, washed-out look from wet rocks or leaves after rain, revealing richer, saturated colors.

Pro Tip: A CPL filter is adjustable. Rotate the outer ring while looking at your camera's screen or app preview to see the effect change in real-time. Find the "sweet spot" where reflections disappear and colors are most enhanced.

2. The ND (Neutral Density) Filter: The Motion Blur Master

Unlike a CPL, an ND filter doesn't change color or contrast. Its sole purpose is to act like sunglasses for your camera, uniformly reducing the amount of light entering the lens. Why would you want less light? To control your shutter speed.

Action cameras often use very fast shutter speeds in auto mode to prevent blur, but this can make moving subjects—like flowing water or a passing landscape from a moving vehicle—look unnaturally sharp and jittery, a phenomenon known as "choppy" footage. By using an ND filter to limit light, you can force the camera to use a slower shutter speed, creating beautiful motion blur that makes footage look smooth and cinematic.

When to use an ND filter:

• Waterfalls & Rivers: To achieve that silky, smooth water effect.
• Fast-Moving Action: When biking, skiing, or driving, an ND filter helps create a more fluid sense of speed.
• Bright Daylight Video: To maintain a cinematic 180-degree shutter rule (shutter speed = 1/(2x frame rate)) in very bright conditions where the camera would otherwise use too fast a shutter speed.

ND filters come in different strengths, like ND8, ND16, or ND32 (the higher the number, the darker the filter and the more light it blocks). A good camera filter kit will include a range, such as an ND8/PL (a combination filter) and an ND16 or ND32 for the brightest days.

3. The UV Filter: Protection First

The UV filter is the simplest of the three. It blocks ultraviolet light, which can sometimes cause a slight bluish haze in distant landscapes, especially at high altitudes. With modern digital sensors, this effect is minimal. Therefore, the primary role of a UV filter today is lens protection.

For an action camera mounted on a helmet, bike, or drone, the lens is incredibly vulnerable to scratches, sand, salt spray, and impacts. A high-quality UV or clear protective filter acts as a sacrificial barrier. It's much cheaper to replace a scratched filter than a scratched camera lens element. Many creators keep a clear filter on their camera at all times for this reason.

How to Use Your Camera Filter Kit: A Step-by-Step Guide

Getting started with filters is straightforward. Here’s a simple workflow:

1. Identify Your Need: Assess the scene. Is there harsh glare? Use the CPL. Is it extremely bright and you want smooth motion? Use the ND. Just need everyday protection? Use the UV/Clear filter.
2. Attach the Filter: Most kits use a simple magnetic or screw-on adapter ring that first attaches to your camera. The filters then quickly snap or screw onto this base. Systems like those for GoPro are designed for easy, tool-free swaps even with gloves on.
3. Configure Your Camera Settings: For ND filters, you may need to switch to manual video mode (if your camera supports it) to lock in a desired shutter speed. For CPL filters, use the preview screen to rotate the filter for the desired effect.
4. Shoot and Review: Take a test clip and review it. With a CPL, adjust the rotation if needed. With an ND, check if the motion looks natural.

Quick Reference: Action Camera Filter Guide

Filter Type	Primary Use	Best For	ONID TECH Kit Example
CPL	Reduce reflections, enhance colors & contrast	Water sports, landscapes, through windows	Often combined with ND (e.g., ND8/PL)
ND (e.g., ND8, ND16)	Reduce light for slower shutter speed & motion blur	Bright sun, waterfalls, creating cinematic motion	Multi-pack with varying strengths
UV / Clear	Lens protection from scratches and impacts	Everyday use, abrasive environments (sand, snow)	Included in most comprehensive filter sets

Choosing the Right Filter Kit for Your Needs

When shopping for a camera filter kit, consider your primary activities. A basic starter kit for general use might include a UV protector and a CPL filter. An enthusiast or creator's kit should add at least two ND filters (like an ND8/PL and an ND16). Premium kits offer a full range of ND strengths and sometimes specialized filters like mist or diffusion filters.

Look for kits made from high-quality optical glass with multi-coatings to prevent lens flare and maintain image sharpness. Ensure the mounting system is secure and designed for your specific camera model—a filter flying off during a mountain descent is the last thing you want. Many of the filter sets available at ONID TECH are designed with robust, reliable mounting systems for active use.

Conclusion

Investing in a versatile camera filter kit is one of the most effective ways to gain creative control and improve the production value of your action camera footage. By understanding the distinct roles of the CPL filter for cutting glare, the ND filter for mastering motion, and the UV filter for essential protection, you can confidently tackle any lighting condition. Start by identifying the challenges in your most common shooting scenarios, experiment with the filters in your kit, and watch as your videos transform with richer colors, smoother motion, and a truly professional polish.