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Nine stops, and a warning about wide lenses

K&F CONCEPT 67 mm variable, ND2-400, 1 to 9 stops, 7.4 mm

One to nine stops on a variable 67 mm filter for 29 €, in Japanese AGC glass — from a page that tells you not to fit it to a lens wider than 35 mm.

K&F Concept variable ND filter with its knurled trapezoid-patterned ring

K&F CONCEPT 67 mm variable, ND2-400, 1 to 9 stops, 7.4 mm

One to nine stops on a variable 67 mm filter for 29 €, in Japanese AGC glass — from a page that tells you not to fit it to a lens wider than 35 mm.

Strength
1 to 9 stops, in the title and the first and fourth bullets, named for long exposures and motion blur in changing light. Nine stops turns a 1/250 second exposure into two seconds — the difference between frozen water and a smooth sheet
Notations given
BOTH, in the title: ND2-400 and 1-9 f-stops. The two notations describe the same thing from opposite ends — ND2 passes half the light and ND400 a four-hundredth — and publishing both saves the arithmetic. The hub above asks for exactly this, and the 186 € NiSi here gives ND0.3-1.5 instead, a third notation again
Fixed or variable construction
VARIABLE, and both filters on this shelf are. A variable ND is two polarising layers rotated against each other, which is why it costs less than nine separate filters and why it has the failure the hub above warns about at the extremes
Thread size
67 mm, in the title
Stated colour cast
NOT ADDRESSED. The second bullet claims intense colours and high contrast from Japanese AGC glass; neutrality is never claimed and no cast is denied. On a variable ND that is the specification most worth having — the 186 € NiSi here sells its True Color coating precisely on preventing a yellow tint
Coatings
Not counted. Japanese AGC glass is named in the second bullet and no layer count appears, where the same maker publishes eighteen layers on its UV and polarising filters
Frame thickness
7.4 mm, in the third bullet, described as very slim with a CNC trapezoid pattern that raises friction so it can be fitted or removed anywhere. Seven point four millimetres is thicker than any polariser on this shelf, which is inherent: a variable ND holds two rotating elements
Amazon reference
B09BCJ6N8G (same reference on 6 Amazon marketplaces)
EAN
6936069271669
  • Two notations published — ND2-400 and 1-9 stops — so no conversion is needed
  • A published 7.4 mm frame with a CNC pattern for grip
  • No colour cast claim either way, on a variable ND

Best for: A 67 mm standard or telephoto lens used for long exposures in changing light, where nine stops in one filter beats carrying four.

≈ 29 €
Check price on Amazon

Specifications

Strength
1 to 9 stops, in the title and the first and fourth bullets, named for long exposures and motion blur in changing light. Nine stops turns a 1/250 second exposure into two seconds — the difference between frozen water and a smooth sheet
Notations given
BOTH, in the title: ND2-400 and 1-9 f-stops. The two notations describe the same thing from opposite ends — ND2 passes half the light and ND400 a four-hundredth — and publishing both saves the arithmetic. The hub above asks for exactly this, and the 186 € NiSi here gives ND0.3-1.5 instead, a third notation again
Fixed or variable construction
VARIABLE, and both filters on this shelf are. A variable ND is two polarising layers rotated against each other, which is why it costs less than nine separate filters and why it has the failure the hub above warns about at the extremes
Thread size
67 mm, in the title
Stated colour cast
NOT ADDRESSED. The second bullet claims intense colours and high contrast from Japanese AGC glass; neutrality is never claimed and no cast is denied. On a variable ND that is the specification most worth having — the 186 € NiSi here sells its True Color coating precisely on preventing a yellow tint
Coatings
Not counted. Japanese AGC glass is named in the second bullet and no layer count appears, where the same maker publishes eighteen layers on its UV and polarising filters
Frame thickness
7.4 mm, in the third bullet, described as very slim with a CNC trapezoid pattern that raises friction so it can be fitted or removed anywhere. Seven point four millimetres is thicker than any polariser on this shelf, which is inherent: a variable ND holds two rotating elements
Amazon reference
B09BCJ6N8G (same reference on 6 Amazon marketplaces)
EAN
6936069271669

On the listing

Six bullets. One to nine stops, the variable ND2-400 intended for long exposure and motion blur in changing light and named for nature and landscape work, with a note that new and old packaging ship at random; premium glass, made from high-grade Japanese AGC glass for optimal brilliance and distance clarity with intense colours and high contrast; extremely slim, the frame only 7.4 mm thick with a CNC trapezoid pattern that raises friction so it can be installed or removed anywhere; motion blur, reducing by one to nine stops for dramatic blur and shallow depth of field in changing light; remarks stating that this variable ND2-400 is not recommended for wide-angle lenses with focal lengths below 35 mm and that a larger lens cap or hood must be used; and a closing bullet claiming the brand is the world’s number one in lens-filter online sales volume among camera-accessory-focused brands, sourced to Euromonitor 2024 data.

Both notations, in the title

ND2-400 and 1-9 stops. One says what fraction passes, the other what the exposure changes by. Publishing both removes the arithmetic the hub above asks readers to do.

Nine stops, which is two seconds of daylight

A quarter of a two-hundred-and-fiftieth becomes two seconds. That is the whole reason a neutral-density filter exists.

The warning in the fifth bullet

Not below 35 mm. A variable ND is two polarisers turned against each other, and on a wide lens that produces a dark X. The maker says so rather than waiting for the review.

Seven point four millimetres, published

Thicker than any polariser on this shelf, and necessarily: two rotating elements need the room. The CNC pattern is there so it can be turned with cold fingers.

What it never claims

Neutrality. On a variable ND, colour cast is the defect that shows most — and this page discusses brilliance and contrast instead.

Availability

Between 29 € and 39 € on the German, French, Italian and Spanish Amazon stores when this page was last checked.

Listed in the American and British Amazon catalogues with nothing on sale against the entry: the camera has a page there and no seller behind it.

Everything in this section is the figure Keepa carried on the day of the last update to this page. Availability and prices shift without notice.

Prices quoted in this text were read on 13 September 2026. The live price is at the top of the page.

More ND filters

  • NiSi True Color variable ND filter with its knurled ring and click-stop markings

    NiSi True Color VND, 82 mm, 1 to 5 stops, no X

    One to five stops in five clicks with no X effect, a coating sold on neutrality and vignetting-free use at 16 mm — the variable ND that trades range for quality, at 186 €.

    Strength
    1 to 5 stops, in the title — deliberately HALF the range of the 29 € K&F here, and the restriction is the point. A variable ND misbehaves at its extremes; stopping at five keeps the filter inside the range where two polarisers still darken evenly
    Notations given
    A THIRD system: ND0.3 to ND1.5 in optical DENSITY, alongside stops in the title. Density is logarithmic — 0.3 is one stop, 1.5 is five — and it is the notation used on cinema filters. Between this page, the K&F’s ND2-400 and the stop figures, this shelf carries three ways of saying the same thing, which is why the hub above asks which notation is given
    Fixed or variable construction
    VARIABLE with FIVE DEFINED CLICK-STOPS, in the second bullet — and clicks are what a variable ND usually lacks. A continuous ring cannot be returned to the same setting twice; five detents mean the third stop is the third stop on every shot of a sequence
    Thread size
    82 mm, in the title — the largest thread in this catalogue, and the size the buying advice above says to buy for and step down from
    Stated colour cast
    ADDRESSED DIRECTLY, alone on this shelf: the first bullet says the exclusive True Color coating prevents the yellow cast common to other brands and guarantees absolutely neutral reproduction with no colour falsification. On a variable ND the yellowing at strong settings is the defect people complain about, and this is the page that names it
    Coatings
    UP TO TWENTY anti-reflective layers, in the third bullet, with double-sided water- and oil-resistant coatings. Fewer than the thirty the NEEWER polariser on this site publishes; more than the unnumbered coating of the 29 € K&F here
    Frame thickness
    NOT PUBLISHED as a figure. What the fourth bullet gives instead is the engineering: a LARGER FRONT THREAD to avoid vignetting at 16 mm, and a matt black interior to absorb stray light. Sixteen millimetres is a specific, checkable claim, where the K&F here says not below 35
    Amazon reference
    B09K57XSZS (same reference on 6 Amazon marketplaces)
    EAN
    6972949372941
    • No X effect, stated explicitly — the failure a variable ND is known for
    • Five defined click-stops, so a setting can be returned to exactly
    • One to five stops, half the range of the 29 € K&F

    Best for: Video and wide-angle landscape work where the filter has to stay neutral, return to a known setting, and work at 16 mm.

    ≈ $245 / £178 / 186 €
    Check price on Amazon

Elsewhere in the camera bag

  • NiSi True Color CPL filter with its knurled frame and blackened glass edge

    NiSi True Color CPL, 77 mm, 20 layers, Cine Sealed

    A hundred and two euros for a polariser whose coating is sold on colour neutrality and whose glass edges are blackened and sealed against condensation.

    Thread size
    77 mm, in the title — the largest on this shelf, and the size the buying advice above says to standardise on, since a step ring brings it down to everything smaller
    Type
    CIRCULAR, in the title. The hub above puts circular versus linear first for a reason: only the circular kind leaves autofocus and metering working
    Light loss stated
    NOT STATED in stops. The first bullet claims 99.9 per cent of light reflections eliminated — the same figure the 28 € NEEWER here publishes — and the exposure penalty a polariser imposes is absent from all four pages on this shelf
    Coating description
    TWENTY layers, in the third bullet, including an ULTRA-LOW-REFLECTION layer specified at 0.2 PER CENT, with double-sided water- and oil-repellent coatings for easy cleaning and scratch resistance. Fewer layers than the thirty of the NEEWER; the difference on this page is what the coating is claimed to preserve rather than how many there are
    Frame thickness
    NOT PUBLISHED — the one number this page omits, at 102 €. The fifth bullet claims no vignetting even on wide-angle lenses and gives no millimetres, where the 18 € K&F publishes 5.3 mm and the 28 € NEEWER 5.9 mm. What IS named is a matt black interior coating in the second bullet, to absorb stray light inside the frame
    Rotation mechanism
    A KNURLED frame — gerändelter Rahmen — in the fifth bullet, described as giving grip for quick mounting and removal. That is about fitting rather than turning; the 28 € NEEWER here is the page that describes the rotation itself
    Amazon reference
    B09XQXPG3C (same reference on 6 Amazon marketplaces)
    EAN
    6972949374020
    • A coating sold on colour neutrality, with the yellow cast of other filters named as the problem
    • Cine Sealed blackened glass edges, credited with preventing condensation
    • No frame thickness published, at 102 €

    Best for: Work where the polariser must not tint the image — video graded across shots, or landscape work in mixed light — and where condensation on a cold morning is a real risk.

    ≈ $129 / £95 / 102 €
    Check price on Amazon
  • PROfezzion 58 mm circular polariser with its rotating ring and case

    PROfezzion 58 mm CPL, twelve layers

    Twelve coating layers on a 58 mm circular polariser for 16 € — from a page whose fourth bullet gives the thread as 52 mm and explains where to check it.

    Thread size
    58 mm in the title — AND 52 mm in the fourth bullet, which says the filter fits any lens with a 52 mm thread. The same bullet then explains, usefully, that the correct size is printed on the lens after a ⌀ symbol. The title and the part number PF-58CPL agree on 58; the bullet is the odd one out, and the ⌀ on the lens settles it
    Type
    CIRCULAR, in the title and throughout. The hub above treats circular versus linear as the first question: a circular polariser keeps autofocus and metering working on a modern camera, and a linear one does not
    Light loss stated
    NOT STATED. A polariser costs light — commonly one and a half to two stops — and no page on this shelf publishes the figure. The hub above asks for it in stops, and four filters here leave it out
    Coating description
    TWELVE layers, multi-coated, in the third bullet, credited with reducing reflection and named for outdoor and landscape work over water, sky and plants. The same count as the maker’s UV filter on this site
    Frame thickness
    Not published — where the same maker publishes 3 mm on its UV filter. On a polariser the frame is necessarily thicker, because it has to rotate, and that makes the missing figure more significant rather than less
    Rotation mechanism
    Not described. A polariser is used by turning it, and how the ring turns — knurled, geared, stiff, smooth — is the whole ergonomics of the thing. The 28 € NEEWER on this shelf describes straight knurling and smooth rotation; this page is silent
    Amazon reference
    B093247YD6 (same reference on 6 Amazon marketplaces)
    EAN
    6940202350500
    • Twelve multi-coating layers, on named Japanese glass in an aviation-aluminium frame
    • A bullet that explains where the thread size is printed, after the ⌀ symbol
    • The title says 58 mm and the fourth bullet says 52 mm

    Best for: A 58 mm lens used over water and foliage, where twelve coating layers for 16 € matter more than a published stop figure.

    ≈ $16 / £13 / 16 €
    Check price on Amazon
  • NEEWER 67 mm CPL filter showing its knurled rotating ring and case

    NEEWER 67 mm CPL, 99.9 per cent, 30 layers, 5.9 mm

    Thirty coating layers, reflection under 0.1 per cent and a published 5.9 mm magnalium frame — the only polariser here that describes how its ring turns.

    Thread size
    67 mm, in the title and the fifth bullet, supplied with a protective case and a cleaning cloth
    Type
    CIRCULAR, in the title, built on what the first bullet calls an imported polarising film. Circular is what keeps autofocus and metering intact, as the hub above explains
    Light loss stated
    NOT STATED — no figure in stops, as on all four polarisers here. What this page does publish is the other side of the transaction: 99.9 per cent of reflections from non-metallic surfaces eliminated, and a minimum light reflection of under 0.1 per cent off the filter’s own surfaces. Both are real numbers; neither is the exposure penalty the hub above asks for
    Coating description
    THIRTY LAYERS of polarising film on both sides of the filter, in the second and third bullets — the highest count on this shelf — with four properties named: water-repellent, oil-repellent, antistatic and scratch-resistant. The same bullet claims ultraviolet blocking from 300 to 380 nm, which is a stated waveband rather than a vague claim
    Frame thickness
    PUBLISHED, and in two parts: an ultra-thin 5.9 mm frame in MAGNALIUM ALLOY, plus a 3.8 mm front bezel that the fourth bullet says effectively prevents vignetting on wide-angle lenses. The 18 € K&F here is thinner overall at 5.3 mm; this is the only page that separates the frame from the bezel
    Rotation mechanism
    DESCRIBED — alone on this shelf. The fourth bullet gives black anodised threads with precision machining for effortless installation, and straight wheels for smooth rotation. A polariser is operated by turning it, and this is the one page that treats the turning as a specification
    Amazon reference
    B09HGHKN2R (same reference on 6 Amazon marketplaces)
    EAN
    0191073121478
    • Thirty coating layers, with reflection under 0.1 per cent and a stated 300-380 nm UV band
    • The only description of a rotation mechanism on this shelf
    • No light loss in stops, as everywhere on this shelf

    Best for: A 67 mm lens whose polariser gets turned constantly — landscapes, water, glass — where a smooth ring and a wipeable coating earn the extra 10 €.

    ≈ $26 / £23 / 28 €
    Check price on Amazon

All ND filters