K&F Concept Variabel ND8-128 ND-filter 

K&F Concept Variable ND8-128 Filter – Nano-X Series with Water and Dust-Proof Coatings

Anyone who’s been following this site for a while will know that I’m not a fan of glass filters, with the main reason being: sharpness loss. And these aren’t just words. After having a suspicion and reading about it on a forum, I decided to do a test with and without a filter. The results were clear: even with an expensive filter on a 300mm pro lens, I could notice a reduction in sharpness. Read more about it here: Olympus 300mm f4 Pro – Sharpness and Hoya Filters.

However, in this case, I bought this filter for video work, and the potential loss in sharpness doesn’t bother me here. Filming on bright, sunny days turned out to be quite difficult — if not impossible — while maintaining a shutter speed of 1/50 at 30fps. This ND filter provides enough range to solve that issue. In practice, I mostly use ND8, ND16, and ND32, while ND64 and ND128 remain available for extreme conditions, like shooting by the sea or in intense sunlight.

My experience with this filter:

For photography, I don’t use ND filters that often. Honestly, with the OM-1 Mark II’s built-in electronic ND, it’s rarely needed. Still, a real filter can be handy, especially for some of my other cameras that aren’t quite as high-tech.

So, I decided to throw a variable ND filter onto my Panasonic 12-60mm f/3.5-5.6 lens — and immediately ran into a tiny snag: the original plastic lens hood wouldn’t fit anymore. The filter has a 58mm thread, so I (without double-checking, of course…) just ordered a 58mm metal hood. Turns out, rookie mistake: while the lens side is indeed 58mm, the outer thread of the filter itself is 62mm. So yeah, the new hood didn’t fit at all. Lesson learned: always check both sides of your filter if you’re planning to add accessories — especially if you’re buying a K&F Concept variable ND.

Anyway, fast forward a few days: I grabbed a 62mm vented metal lens hood instead. Bonus: I can now use the hood itself to turn the filter and adjust the strength — way easier than fumbling with the little notches on the filter ring. Unexpected win!

For my video work with the Lumix G81M and the Panasonic 12-60mm, I’ve been using the K&F Concept ND Filter 8–128 Nano-X Series a while now, and in short: it’s been excellent. Great optical quality, a wide usable range, and no nasty color shifts — everything you want when you’re trying to wrangle exposure in shifting light.

I’ll be honest — at first, I had my doubts. A variable ND filter? Could it really match the quality of a set of fixed filters?
I’d also read some scary stories about weird dark spots — like an X-shaped shadow appearing in the frame. Not exactly confidence-inspiring.

But after actually using it for video, I have to say: I’m seriously impressed. No strange artifacts, no weird shadows — honestly, I don’t even notice it’s there. Except that now, exposure is totally under control.

Sharpness? I didn’t do a full pixel-peep test yet. For my photography, especially shooting birds and wildlife, ultimate sharpness does matter — I didn’t invest in good glass just to end up with soft shots.
With video, you’re a bit more forgiving. But even so, so far, no complaints in the sharpness department either.

Quick heads-up though: if you’re shooting photos at the wide 12mm end with this setup, you’ll get heavy vignetting with the hood on. No drama for video, though — the G81M crops the sensor slightly during recording, neatly trimming away the dark corners. Still, something to keep in mind if you’re planning to switch between stills and video on the fly.

Bottom line? I’m seriously happy with this filter. It handles glare and reflections like a champ, the Nano-X coating shrugs off water and dust (perfect for outdoor shooting), and it won’t break the bank. Solid choice if you’re after a good variable ND for both photography and video.

Price: Approximately €60 (58mm version), including shipping.

Purchased from the K&F Concept Brand Store on AliExpress.

Pictures used for header and article courtesy of K&F Concept – https://www.kfconcept.com/