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Magnetic filter systems cut the time it takes to swap an ND or CPL, but the Kase vs Freewell decision is really an ecosystem decision, not a glass comparison. If you are coming from a threaded lens filter workflow, the core change is a lens-side base ring that stays attached so filters snap on magnetically.
The format has matured quickly. Kase Revolution Plus now spans 46mm through 112mm native sizes, while Freewell splits into two distinct families: the fixed-ND M2 system and the Brandon Li VND/CPL system. Each solves a different problem, and several generations within each brand are not cross-compatible.
This guide covers how magnetic mounting actually works, what the Kase and Freewell architectures do differently, where fixed ND beats variable, and what independent testing shows about stacking, vignetting, and color. It is written for photographers and video shooters who want to avoid buying into a generation that will not expand cleanly.
If you mainly need a single set of high-quality ND densities, start with the best ND filters guide first. If you already know you want magnetic, the decision tree below will tell you which ecosystem fits.
Quick Reference
| Use case | Strongest fit | What you get |
|---|---|---|
| Long-exposure landscape stills | Kase Revolution Plus Pro or Mega | 3-, 6-, and 10-stop fixed ND plus CPL |
| Value-focused stills setup | Freewell M2 5-Pack | ND8, ND64, ND1000, CPL, UV |
| Run-and-gun video exposure | Freewell x Brandon Li VND/CPL | 1–5 stops, extending to 6–10 with ND32 |
| Multi-lens owner with odd thread sizes | Kase Revolution Plus | Native 46–112mm coverage |
| Existing Revolution owner | Kase Revolution Plus | Backward-compatible with the Revolution family |
How Magnetic Filter Systems Actually Work
A magnetic filter system still begins with a threaded lens interface. The magnetic part is the filter itself; the base component screws into or into the lens filter thread first. After that, ND, CPL, UV, or mist elements attach and release magnetically.
Kase uses an inlaid adapter ring that sits inside the lens filter thread, keeping the first magnetic filter closer to the front element. Freewell M2 uses a threaded empty base ring that screws onto the lens and creates the magnetic receiving surface.
The benefit is speed. Swapping a CPL for a 6-stop ND takes seconds instead of a careful screw-in change, which is why landscape shooters and gimbal video shooters consistently prefer magnetic systems. What magnetic mounting does not do is guarantee better optical quality: sharpness and color still depend on the glass, coatings, and filter design.
Compatibility is the hidden trap. Freewell M2 is not compatible with M1, V2, or K2. Brandon Li standard and Cine base rings are not interchangeable, including their respective 82mm versions. Matching nominal filter diameter does not make two magnetic systems compatible.
Kase Revolution Plus: The Broad Still-Photography Ecosystem
Kase Revolution Plus is the more extensive fixed-ND ecosystem of the two. It uses KW optical glass, revised nano-coatings, thinner frames intended to reduce vignetting, and a magnetic family that is backward-compatible with earlier Revolution components.
| Kit | Included filters | Native sizes | What it adds |
|---|---|---|---|
| Entry Kit | CPL, ND8 (3-stop), ND64 (6-stop) | 67, 72, 77, 82, 95, 112mm | Inlaid adapter, magnetic cap, pouch |
| Pro Kit | CPL, ND8, ND64, ND1000 (10-stop) | 46–112mm across 13 sizes | The 10-stop ND for long exposure |
| Mega ND Kit | CPL, ND8, ND64, ND1000, Neutral Night, MCUV | 49–112mm across 12 sizes | Four inlaid adapter rings for multi-lens setups |
| Individual filters | ND8, ND64, ND1000, CPL, MCUV, Neutral Night, GNDs, Black Mist | Varies by filter type | Build a custom set |
| VND & CPL | 1.5–5 stop or 6–9 stop | 49–82mm across 9 sizes | Variable density plus CPL in one magnetic filter |
The Pro Kit is the logical landscape choice because it supplies 3-, 6-, and 10-stop fixed NDs in one package. The Mega Kit is not better glass; it adds Neutral Night, MCUV, and multiple inlaid rings for photographers who routinely move between several lenses.
Independent testing of the preceding Revolution generation found the tested ND filters essentially neutral and without meaningful sharpness loss, while the CPL introduced slight warmth. That is useful evidence about the system concept, not a laboratory claim about every Revolution Plus filter.
The broad native size range is Kase's biggest structural advantage. If you own lenses with threads from 46mm to 112mm, you can stay inside one magnetic family instead of adapting across systems.
Freewell M2: The Value-Focused Fixed ND System
Freewell M2 is built around three native diameters: 67mm, 77mm, and 82mm. It uses German optical glass, a multi-layer protective coating, and a threaded empty base ring.
| Bundle | Included | Native sizes | Notes |
|---|---|---|---|
| 3-Pack | ND1000, CPL, UV | 67/77/82mm, 82mm verified | Base ring, cap, pouch, cleaning cloth |
| 5-Pack | ND8, ND64, ND1000, CPL, UV | 67/77/82mm | The clearest value proposition in the research set |
| 5-Pack Pro Kit | 5-Pack filters plus Freewell Pro Card Reader | 67/77/82mm | Same glass, no optical upgrade |
| Individual filters | ND, UV, CPL, Glow Mist, Snow Mist | Per-size availability varies | Each package includes a base ring |
| Empty base ring | Threaded magnetic interface | 67/77/82mm | M2-specific |
| Step-up rings | Multiple combinations from 49→82 up to 95→112 | Varied | CNC aluminum, blackened finish |
The 5-Pack is the strongest entry point for stills photographers who want three fixed ND densities plus CPL and UV without buying a large system. The 3-Pack is simpler: a 10-stop ND, CPL, and UV for long-exposure work. Freewell has been recognized by an independent buyer's guide as a budget magnetic system pick.
One ergonomic caveat matters: the magnets are strong enough that rotating the CPL can, on some setups, tighten or loosen the lens-side base ring. That is not a widespread failure, but it is a good reminder that stronger magnets are not automatically better.
M2 also supports stacking, but Freewell explicitly warns that additional glass layers can increase softness and vignetting risk. Freewell reports testing a single M2 filter at 16mm full-frame without a vignette issue, while noting that lens design and stacking can change the outcome.
Freewell x Brandon Li VND/CPL: The Video-Focused Option
For video, Freewell's strongest purpose-built magnetic system is the Brandon Li VND/CPL line. It combines a 1–5 stop variable ND with an independently adjustable CPL, and the supplied ND32 extends the range to 6–10 stops.
| Kit | Included | Standard sizes | Architecture |
|---|---|---|---|
| Basic | VND 1–5 + CPL, ND32, one base ring, cap/gray card | 67, 72, 77, 82mm | Magnetic alignment plus mechanical twist lock |
| Pro | Basic plus Black Glow Mist 1/4 | 67, 72, 77, 82mm | More elaborate case |
| Cine / Cine Pro | Larger VND/CPL and ND32 | 86mm, 95mm | Not interchangeable with standard bases |
The locking mount is the important design change. Magnets align the filter, then a short physical twist locks it to the base. That directly addresses the accidental-detachment anxiety that can come with pure magnetic retention.
The optical assembly is oversized relative to the thread size: the VND/CPL is 95.5mm in outer diameter, while the standard base ring is 91.8mm, even for smaller thread sizes. That extra diameter is intended to reduce wide-angle mechanical vignetting.
Independent testing of the Brandon Li system found no VND "X pattern," no observed vignetting at 24mm in the tested multi-element combination, and only a minor yellow shift from the VND/CPL alone. Adding ND32 made the image visibly warmer. For straight-out-of-camera color neutrality, fixed NDs remain the more predictable choice; for graded video, the warmth is correctable.
Fixed ND vs Variable ND: The Decision That Matters More Than Brand
For many buyers, the more important choice is not Kase vs Freewell but fixed ND vs variable ND.
Fixed ND8, ND64, and ND1000 give repeatable, predictable density for long-exposure stills. Variable ND gives continuous control, which is more useful when you need to hold a specific shutter angle or exposure while light changes.
| Workflow | Better choice | Why |
|---|---|---|
| Long-exposure stills | Fixed ND | Predictable density and neutral rendering |
| Run-and-gun video | Variable ND | Adjust exposure without swapping filters |
| Hybrid stills + video | Consider two systems | Fixed ND for stills, VND for video |
| Straight-out-of-camera color | Fixed ND | Less setup-dependent cast |
If your primary output is stills, the best ND filters guide explains which fixed strengths matter for different subjects. If you shoot video, a variable magnetic option like Brandon Li is usually the more practical buy.
Adapters, Step-Up Rings, Lens Hoods & Caps
Oversizing is the practical wide-angle workaround. The safest buying logic is usually: use the largest lens thread you own as the system diameter, then adapt smaller lenses upward. Kase and Freewell both support this, but the mechanical details differ.
Kase's two-part Inlaid Magnetic Step-Up Ring Pro keeps a thin threaded ring installed in the lens, then snaps a larger magnetic step-up section on only when needed. Current combinations include 67→77, 67→82, 67→95, 72→77, 72→82, 77→82, 77→95, and 82→95. Removing the oversized magnetic section while leaving the inlaid base installed allows most original caps and hoods to function.
Freewell offers a broad set of magnetic/threaded step-up combinations from 49→82 up to 95→112. The blackened internal finish is designed to suppress reflections. Freewell also confirms that an ordinary third-party step-up ring can sit underneath the correct M2 base when an exact Freewell combination is unavailable.
The hood and cap rules are simple but often ignored:
- A same-diameter M2 setup can usually retain the original lens hood.
- Stepping a smaller lens up to a larger magnetic diameter normally prevents use of that lens's smaller original hood.
- Both brands supply dedicated magnetic caps. Freewell's M2 cap has a pull holder designed for removal inside a compatible same-diameter hood.
- Neither system should be advertised as universally compatible with the lens's original cap and hood.
If you are unclear whether a hood is worth replacing, the lens hood and cap guide covers the practical tradeoffs.
Stacking, Vignetting & Color Cast: What Testing Shows
Stacking is supported by both systems, but it has measurable consequences. More glass surfaces increase flare risk, and increased physical depth raises the chance of filter frames becoming visible on wide-angle lenses.
The evidence is specific:
- A Kase Revolution hands-on test found a single filter vignette-free at 24mm, while a CPL + ND64 stack showed corner vignetting.
- A separate independent test using a 112mm Kase setup reported no vignette at 14mm with ND + CPL, confirming that substantial oversizing helps.
- Freewell reports a single M2 filter tested at 16mm full-frame without vignetting, while warning that stacking can alter the outcome.
- A Brandon Li independent review found no vignette at 24mm in the reviewed setup, but one user still reported slight wide-end vignette on a 20mm lens despite upsizing.
The lesson is not "don't stack." It's that there is no universal safe focal length. The exact lens, filter diameter, adapter depth, and number of stacked filters all matter. If you frequently shoot at 14–20mm, the ND filter size and fit guide is a useful companion before you buy.
Color cast is similarly nuanced. Independent testing found Kase fixed NDs effectively neutral, while the CPL added slight warmth. Freewell M2 owners generally report little or no visible cast. Brandon Li's VND/CPL was nearly neutral alone but became warmer with ND32 added.
"Color neutral" is a manufacturer specification, not a universal guarantee. A filter can be excellent and still produce a small setup-dependent cast.
Kase vs Freewell: Which Ecosystem Should You Buy Into?
The right answer depends on workflow and lenses. Use the decision table before choosing between brands.
| Profile | Strongest fit | Reason |
|---|---|---|
| Long-exposure landscape photographer | Kase Revolution Plus Pro or Mega | 3/6/10-stop fixed NDs, inlaid adapters, broad sizes |
| Value-focused stills photographer | Freewell M2 5-Pack | ND8/ND64/ND1000, CPL, UV at a simple system price |
| Run-and-gun filmmaker | Freewell x Brandon Li Basic or Pro | 1–10 stops, independent CPL, locking mount |
| Multi-lens owner with small or unusual threads | Kase Revolution Plus | Native coverage from 46mm to 112mm |
| Travel photographer using 67/77/82mm lenses | Freewell M2 | Compact, simple, smaller ecosystem |
| Ultra-wide shooter | Neither blindly | Oversize where possible, then test the exact lens/stack combination |
| Already invested in Kase Revolution | Kase Revolution Plus | Backward ecosystem compatibility |
| Existing Freewell owner | Check generation first | M2, Brandon Li, Versatile, and Dunna systems are not interchangeable |
Within Freewell, the most common mistake is assuming all "Freewell magnetic" components work together. The M2 system, the Brandon Li system, the older Versatile magnetic VND, and the newer Dunna fixed-ND locking system are separate architectures. Brandon Li standard and Cine bases are also not interchangeable.
Within Kase, the important distinction is the older "Magnetic VND" generation versus the current Revolution Plus VND & CPL. The older version used a VND-specific mounting arrangement, not the ordinary magnetic mount of the current line.
Frequently Asked Questions
Q: Do magnetic filter systems attach without any threading?
No. Both Kase and Freewell still require a lens-side threaded component. Kase uses an inlaid adapter inside the lens filter thread; Freewell M2 uses a threaded empty base ring. After that, the filters attach magnetically.
Q: Are Kase and Freewell magnetic filters cross-compatible?
No. Matching filter diameter is not proof of compatibility. Freewell in particular uses different geometries and polarities across its own systems, and community reports frequently show Kase and Freewell components will not interchange reliably. Stay within the manufacturer's supported ecosystem.
Q: Do magnetic filters cause vignetting on wide-angle lenses?
They can. A single filter is often fine, but stacking a CPL and ND increases physical depth and can darken corners on ultra-wide lenses. Oversizing the filter diameter helps, but there is no universal safe focal length.
Q: Should I buy fixed ND or variable ND for hybrid video and stills work?
If your primary output is video with changing light, a variable ND is usually more practical. If you prioritize long-exposure stills and straight-out-of-camera color, fixed ND8/ND64/ND1000 densities are more predictable.
Q: Can I use my original lens cap and hood with a magnetic system?
Sometimes, but not universally. A same-diameter Freewell M2 setup can often retain the original hood. Upsizing to a larger magnetic diameter normally prevents use of the original smaller hood. Kase's two-part inlaid Pro step-up allows most original caps and hoods after the oversized section is removed.
Q: Is Freewell M2 compatible with other Freewell magnetic systems?
No. M2 is not cross-compatible with M1, V2, K2, the Brandon Li system, the older Versatile magnetic VND, or the Dunna locking system.
Q: Do magnetic filters have a color cast?
Most tested examples show little or no cast, but performance is setup-dependent. Kase fixed NDs tested essentially neutral while the CPL was slightly warm; Brandon Li's VND/CPL was nearly neutral alone but became warmer with ND32 added. Treat "color neutral" as a manufacturer specification, not an absolute guarantee.
Q: Which is better for long-exposure landscape photography: Kase or Freewell?
Kase Revolution Plus has the broader fixed-ND and adapter ecosystem for long-exposure stills. Freewell M2 5-Pack is the stronger value if you only need a simple fixed set and are comfortable with its 67/77/82mm platform.
Conclusion
The real question is not "Are Kase and Freewell worth it?" but which magnetic ecosystem you are actually buying into. Both solve the same workflow problem: faster swaps through a magnetic interface, with a threaded base ring still required at the lens.
If you want the broadest fixed-ND system for landscape work, Kase Revolution Plus is the safer default. If you want a compact, high-value fixed kit in the most common filter sizes, Freewell M2 delivers. If you shoot run-and-gun video, the Brandon Li VND/CPL is Freewell's most compelling magnetic option, and its mechanical twist lock addresses a genuine weakness of pure magnetic retention.
Before buying, confirm your largest lens thread size, decide whether you need fixed or variable ND, and check whether any existing filters you own belong to an older generation. For the full context, see the lens filters guide, the best ND filters guide, the UV filter guide, and the ND filter size and fit guide.
