As a K&F user with several of their filters already in my bag, the quality of this 77mm Mist Filter is exactly what I have come to expect: the build quality is top-tier, and the threading is smooth. If you are familiar with K&F, the premium feel is consistent here.

My Current Challenge (and why I still rate it 5 stars)

I am currently struggling to dial in the correct use for this specific filter on my longer telephoto glass (the Sony 70-200mm and 100-400mm).

The effect I am getting is softer/blurrier than the subtle diffusion I was aiming for. I have done some research and attempted different techniques, but I haven't been able to achieve a result I'm happy with yet.

However, I firmly believe this is a photographer issue, not a product issue. Specialty filters like these, particularly when paired with high-resolution telephoto lenses, can have a steep learning curve. The filter itself is constructed perfectly, and I have high confidence in the K&F optics. I'm rating it 5 stars based purely on the excellent physical product quality and value.

I will keep practicing, perhaps starting with a shorter prime lens to better understand the effect, and may update this review later. If you know how to use mist filters, this is a beautiful piece of glass. If you're a beginner like me, be ready to spend some time learning how to properly incorporate it into your workflow.