Product concept
The Kenko Variable ND-W filter allows you to adjust the amount of light reduction by rotating the front frame. This filter is essential for controlling exposure when filming videos with a single-lens reflex camera, and can also be used for slow shutter photography of still images. The Kenko Variable ND-W was designed using a unique manufacturing method to minimize X-shape pattern, and it expands the usable range on the wide-angle side, which was previously an issue with variable ND filters. With a wide angle lens of 24mm*, it can be practically used from ND2.5 to ND128**.
The frame is marked with indicators of the amount of light reduction, so you can quickly set it to the required density.
* Equivalent to full-size.
** It is recommended to use only up to ND128. While the filter allows to reduce the amount of light to around ND1000, this increases to likelihood of X-shape pattern and color shift. The usable range of the ND is provided as a guideline only. There may be slight differences depending on compatibility with the lens actually used.
Features
Reduces the possibility of X-shape pattern even with wide-angle
The Kenko Variable ND-W was designed using a unique manufacturing method to minimize X-shape pattern, and expands the practically usable range at the wide angles, which was previously an issue with variable ND filters.
With a wide angle of 24mm, the Kenko Variable ND-W can be used from ND2.5 to ND128.
Example of X-shape pattern
Focal length of 24mm, equivalent to ND128 (7 steps of light reduction).
What is "X-shape pattern"?
Due to the mechanism behind variable ND filters, X-shaped pattern can occur when the density is increased. The shorter the focal length of the lens used, the more likely this phenomenon is to occur.
Indicators of the amount of light reduction
The frame is marked with indicators* that serve as a guideline for the amount of light reduction. This enables you to quickly set it to the required ND.
Numbers and density listed: 2 (ND4) / 3 (ND8) / 4 (ND16) / 5 (ND32) / 6 (ND64) / 7 (ND128)
* The indicators on the frame are provided as a guideline only. Due to the structure, there may be slight errors in the position of the numbers indicating the minimum, maximum, and amount of light reduction, as well as in the filter effect.
A movable range of 90°, with a removable lever
The filter comes with a convenient lever for video filming. In addition, the rotating frame has a movable range of 90° between minimum and maximum density, enabling smooth filming. The lever can be attached in two positions, allowing you to choose the position that is more convenient for you. It comes with two levers, one of which is a spare.
Low reflection Digital Multi-Coating II
The filter uses low-reflection Digital Multi-Coating II (with a surface reflection of 0.6 to 1%) to reduce excess flare and ghosting.
Water and oil repellent coating
The water- and oil-repellent coating makes it harder for water droplets and dirt to adhere to the filter, and any amount that does adhere can be easily wiped off.
Uses a polarizing film with minimal color cast
Most commercially-available ND filters with a variable range from ND2 have a slight yellowish tint, but the Kenko Variable ND-W uses a polarizing film with minimal color cast.
Designed to eliminate polarization effect
The polarizing film used in variable ND filters has a polarizing effect. This is problematic because the surface reflection of the subject may disappear or increase as an unintended consequence when changing the density. The Kenko Variable ND-W is designed to prevent this polarizing effect.
Benefits of using a variable ND filter
With a normal ND filter, you need to switch to the ND4 or ND8 filter depending on the circumstances of the shot. However, with a variable ND filter, you can freely adjust the amount of light reduction by simply rotating the front frame. In addition, when using a dark ND filter, it was necessary to attach and detach the filter each time you wanted to set the composition or focus. However, with a variable ND filter, you can turn the brightness all the way up when setting the composition and focusing, and then rotate the front frame to the desired density, so there is no need to switch the filter.
Why high quality Variable ND is important?
A must-have for video filming
When filming videos, the appropriate shutter speed depends on the frame rate (fps). Normally, a shutter speed of up to twice the frame rate is appropriate.
Examples
- For 60 fps, the appropriate shutter speed would be 1/125s.
- For 30 fps, the appropriate shutter speed would be 1/60s.
If the shutter speed is too fast, motion in the video will be disjointed and the video will seem jerky and unnatural. However, using an ND filter to set the shutter speed to an appropriate value will enable you to film smooth, natural-looking videos. This is particularly necessary when shooting with a bright aperture value to blur the background.
Prevents overexposure when shooting with the aperture wide open
When shooting in bright sunlight using an open aperture f/1.4, f/1.2, or other fast lens, the image may whiteout even with a shutter speed of 1/8000th of a second. Under such circumstances, you can prevent overexposure by reducing the light using the Kenko Variable ND-W.
For slow shutter photography of still images
Without an ND filter, to slow down the shutter speed, you would need to close the aperture to near minimum, which would negatively impact the quality of the image. With the Kenko Variable ND-W you can achieve slow shutter speeds with the aperture in a position that maintains the resolution of the lens. This enables you to express the blur of subjects in motion, such as water, people, and cars.
Precautions for use
- When the density is close to maximum, X-shape pattern may appear on the screen, or the image may take on a reddish or bluish tint, so care must be taken when adjusting the density. The shorter the focal length, the greater the effect.
- Exposure compensation may be required to get the correct brightness.
- The indicators on the frame are provided as a guideline only. Due to the structure, there may be slight errors in the position of the numbers indicating the minimum, maximum, and amount of light reduction, as well as in the filter effect. Please check the exposure value displayed on the camera for the amount of light reduction. The amount of light reduction on the minimum side of the variable ND filter changes gradually but drops sharply near the maximum setting.
- When shooting with a slow shutter speed using a single-lens reflex camera, light can enter from behind through the filter. It is recommended that you block the light from the viewfinder using an eyepiece shutter, etc.
- This product uses a polarizing film, which deteriorates when exposed to heat and UV rays. It is recommended that you replace the film every seven years.
- Not suitable for solar photography.
