Why use a Variable ND-CPL for video?
When shooting video outdoors, you often face two problems: too much light for your preferred shutter speed and aperture, and unwanted glare from water, glass, or wet surfaces. The K&F Concept 49mm Variable Filter ND4-ND64 & CPL 2-in-1 solves both without stacking separate filters.
The variable ND side cuts 2 to 6 stops of light (ND4 to ND64), letting you keep a wide aperture or a 180° shutter angle in bright sun. The CPL side reduces reflections and can boost color and contrast. Because both functions are in one filter, you avoid the extra weight and potential vignetting of a stacked setup.
Setting up the filter for video
Check your lens filter thread diameter before ordering. This version fits lenses with a 49mm rear mounting thread. Look for the Ø symbol on your lens barrel or front cap.
- Mount the filter: Screw the 49mm filter onto your lens until it's snug. The aluminium ring has a non-slip finish that makes this easier.
- Set your video exposure: With the filter at its minimum ND4 setting, adjust your camera's aperture, shutter speed, and ISO as you normally would for the scene. For video, a 180° shutter rule (shutter speed double your frame rate) is a good starting point.
- Adjust the ND level: Rotate the filter ring to increase light reduction. The control lever helps you make fine adjustments while looking through the viewfinder. Stay within the marked min/max range to avoid the X-cross pattern that can appear beyond the usable ND range.
- Use the CPL function: The CPL effect is also controlled by rotation. Rotate the filter to see reflections diminish on non-metallic surfaces like water or glass. You can fine-tune both ND and CPL at the same time, though the CPL effect is most noticeable at the minimum ND setting.
Exposure tips for outdoor video
The 2-6 stop range covers most daylight conditions. Start at ND4 (2 stops) and increase until your exposure matches the look you want. If you need more than 6 stops, consider a fixed ND filter or a variable filter with a wider range.
For run-and-gun shooting, the variable design means you can adjust exposure without swapping filters as the sun goes behind a cloud or you move from shade to direct light. The control lever makes this one-handed adjustment practical while the camera is on a gimbal or tripod.
Key features at a glance
- K&F Concept 49mm Variable Filter ND4-ND64 & CPL 2-in-1 Lens Filter: 2-in-1 Variable ND4-ND64 and Circular Polarising Filter Combines two essential tools for video exposure and glare control in one compact filter.
K&F Concept 49mm Variable Filter ND4-ND64 & CPL 2-in-1 Lens Filter - K&F Concept 49mm Variable Filter ND4-ND64 & CPL 2-in-1 Lens Filter: Designed to help prevent X-cross patterns with defined min and max positions Avoids the dark cross artifact that can ruin footage when using variable ND filters beyond their intended range.
- K&F Concept 49mm Variable Filter ND4-ND64 & CPL 2-in-1 Lens Filter: Multi-coated optical glass with aluminium ring Reduces flare and ghosting, while the ring's sandblasted finish minimizes stray light reflections.
- K&F Concept 49mm Variable Filter ND4-ND64 & CPL 2-in-1 Lens Filter: Integrated control lever for easier rotation Allows precise ND adjustment while looking through the viewfinder, useful for video where you can't take your eye off the scene.
When a 2-in-1 filter makes sense
If you shoot video outdoors regularly—landscapes, travel, vlogging, or events—the convenience of having ND and CPL in one filter is hard to beat. You don't need to carry separate filters or waste time stacking them. The 49mm thread size suits many mirrorless and DSLR kit lenses, so check your lens diameter first.
The trade-off is that you can't use the CPL independently without the ND effect, and the CPL effect may be less noticeable at higher ND settings. For most video work, this isn't a problem because you'll typically set the ND first, then fine-tune the CPL by rotating the filter.
