Exploring the K&F CONCEPT Black Diffusion 1/4 & Variable ND2-400 Filter

by | Jun 2, 2023

In my latest video, I dive into the world of camera filters with the K&F CONCEPT Black Diffusion 1/4 & Variable ND2-400 Filter. This unique combination filter offers both variable ND and black diffusion capabilities, aiming to enhance the cinematic quality of video footage. Here’s my in-depth review based on real-world testing.


Unboxing and First Impressions

The filter arrived in impressive packaging, complete with a faux leather case featuring a magnetic flap and an orange ribbon for easy filter removal. The build quality felt solid, with smooth threads that easily attached to my lens using a step-up ring.

Testing the Filter

I tested the filter in various lighting conditions, including bright midday sun and shaded woodland areas. The variable ND aspect performed admirably, allowing me to maintain my preferred shutter speed and aperture without any noticeable color cast. The black diffusion effect was particularly striking in situations where light sources were directly hitting the filter, creating a dreamlike, soft-focus effect on the highlights.

Usability and Features

  • Build Quality: The filter’s construction is robust, and the threads are smooth, ensuring easy attachment to the lens.
  • Orange Tab Indicator: A handy feature for quickly gauging the ND level at a glance.
  • Resistance in Adjustment: The filter has a bit of resistance when adjusting the ND level, which feels high-quality but can be slightly challenging when making quick adjustments.

Pros and Cons

  • Pros:
    • High-quality build and smooth operation.
    • Effective ND filtering without significant color cast.
    • The black diffusion effect creates a cinematic look, especially in the right lighting conditions.
    • Combined functionality reduces the need for multiple filters.
  • Cons:
    • Lack of hard stops on the ND range can lead to accidental over-adjustment.
    • The combined nature of the filter means you can’t use the ND and diffusion effects separately.
    • In very bright conditions, the ND range might not be sufficient for lower frame rates.

Pricing and Value

The filter is mid-range in terms of pricing. It’s more affordable than high-end options like the Moment filter or the Polar Pro Peter McKinnon series but offers better quality than the cheapest filters on the market. This makes it a good investment for those who want quality without breaking the bank.

Final Thoughts

Overall, the K&F CONCEPT Black Diffusion 1/4 & Variable ND2-400 Filter is a valuable addition to any filmmaker’s toolkit, especially for those looking to add a cinematic flair to their footage. While it has a few minor drawbacks, its benefits in terms of build quality, functionality, and the aesthetic effect it brings to footage make it a worthwhile investment.


For a more visual representation and detailed insights, be sure to watch my YouTube video where I test and discuss the K&F CONCEPT Black Diffusion 1/4 & Variable ND2-400 Filter.


Links to Gear


This post is based on my personal experience and review of the K&F CONCEPT Black Diffusion 1/4 & Variable ND2-400 Filter, as detailed in my YouTube video. For more insights and examples, be sure to watch the video.

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