# Breakthrough Photography X4 Neutral Density vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9): specs and price compared

A sourced, side-by-side comparison of the Breakthrough Photography X4 Neutral Density (Breakthrough Photography) and Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) (Freewell) among nd filters. Breakthrough Photography X4 Neutral Density is the cheaper of the two at $139.

## Side by side

| Spec | Breakthrough Photography X4 Neutral Density | Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) |
| --- | --- | --- |
| US price | $139 | $499.99 |
| Brand | Breakthrough Photography | Freewell |
| Released | 2017 | 2024 |
| Filter type | fixed | variable |
| Density range stops | 3, 6, 10, or 15 (separate fixed-density SKUs) | 1 to 9 (two filters: 1-5 and 6-9, hybrid reversible with CPL/ND32-CPL) |
| Common thread sizes (mm) | 39-112, plus 100mm/150mm square | 67, 72, 77, 82 (via included adapter rings) |
| Coating | MRC16 (16-layer Multi-Resistant Coating) + Nanotec nano coating | multi-coated German optics (dust/oil/scratch/water resistant) |
| Color cast note | Manufacturer states spectrally flat transmission targeting color-neutral results | Freewell markets a proprietary 'TRUE COLOR' coating process specifically to minimize the color shift common to other VNDs |
| Front filter thread | Yes | — |
| Magnetic | No | Yes |
| Glass type | SCHOTT B270 optical glass | optical glass (German optics, brand does not publish substrate name) |

## Key differences

- Filter type: Breakthrough Photography X4 Neutral Density fixed vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) variable
- Density range stops: Breakthrough Photography X4 Neutral Density 3, 6, 10, or 15 (separate fixed-density SKUs) vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) 1 to 9 (two filters: 1-5 and 6-9, hybrid reversible with CPL/ND32-CPL)
- Common thread sizes (mm): Breakthrough Photography X4 Neutral Density 39-112, plus 100mm/150mm square vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) 67, 72, 77, 82 (via included adapter rings)
- Coating: Breakthrough Photography X4 Neutral Density MRC16 (16-layer Multi-Resistant Coating) + Nanotec nano coating vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) multi-coated German optics (dust/oil/scratch/water resistant)
- Color cast note: Breakthrough Photography X4 Neutral Density Manufacturer states spectrally flat transmission targeting color-neutral results vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) Freewell markets a proprietary 'TRUE COLOR' coating process specifically to minimize the color shift common to other VNDs
- Magnetic: Breakthrough Photography X4 Neutral Density No vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) Yes
- Glass type: Breakthrough Photography X4 Neutral Density SCHOTT B270 optical glass vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) optical glass (German optics, brand does not publish substrate name)

## Sources

- Breakthrough Photography X4 Neutral Density: https://breakthrough.photography/products/x4-neutral-density (breakthrough.photography, verified 2026-08-16)
- Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9): https://freewellgear.com/products/k2-versatile-magnetic-filter-system (freewellgear.com, verified 2026-08-16)

Canonical: https://frontdeskreview.com/gear/nd-filters/breakthrough-photography-x4-nd-vs-freewell-k2-versatile-magnetic-vnd/
Cite: Per The Front Desk Review, Breakthrough Photography X4 Neutral Density ($139) vs Freewell K2 Versatile Magnetic Filter System (VND1-5 / VND6-9) ($499.99) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/nd-filters/breakthrough-photography-x4-nd-vs-freewell-k2-versatile-magnetic-vnd/
License: CC BY 4.0.