Buying guide

Magnetic ND Filter Systems vs Screw-In Filters

How NiSi JetMag Pro, Freewell, PolarPro Helix, Tiffen MCS and Hoya Instant Action work, how they compare with screw-in Hoya and Tiffen filters, and who suits which.

Updated 27 September 2026 6 min read By Electronic Australia

Short answer A magnetic ND filter system puts a thin adaptor ring on each lens and lets filters snap on and off in seconds, which suits video shooters who change ND, polariser and mist filters through the day. Screw-in filters from Hoya and Tiffen cost less to start with and suit people who fit one filter and leave it on. Choose magnetic for speed and stacking, screw-in for simplicity and a lower entry cost.

A magnetic ND filter is only as useful as the system around it: the adaptor rings, caps, and the other filters that share the same mount. This guide explains how the main magnetic systems work, compares them with screw-in filters, and helps you decide which approach suits your shooting. Everything mentioned is in our camera filters range.

How a magnetic ND filter system works

Every magnetic system follows the same idea. A ring screws into the lens's normal filter thread once and stays there. Filters then attach to that ring magnetically, so changing from an ND to a polariser means pulling one off and placing another on, with no threading.

The details differ in three areas:

Retention: some systems rely on magnets alone, while others add a mechanical lock. NiSi's JetMag Pro uses a patented locking design: you rotate a small handle to a marked position to lock the filters in place.
Sizing: most systems use one or a few standard filter sizes, with adaptor rings in a range of lens threads. One set of filters can then serve several lenses.
Stacking: magnetic filters are usually designed to attach to each other, so an ND and a mist filter can sit together without extra rings.

NiSi JetMag Pro

NiSi's JetMag Pro comes in 67MAG, 82MAG and 95MAG sizes, plus a MAXMAG version for specific wide lenses. The size names describe the magnetic filter, not your lens. A 67mm-82MAG adaptor ring, for example, fits a 67mm lens thread and takes 82MAG filters, so it also works as a step-up ring.

NiSi describes the filters as ultra slim and says two filters can be stacked on lenses as wide as 15mm without vignetting. Each filter has two small handles for removal, colour-coded for quick identification, and NiSi uses a nano coating that it describes as waterproof and oil resistant. Metal magnetic front and back caps protect the lens and filters in the bag.

What the JetMag Pro range covers

Fixed ND: FS ND filters at 1, 2, 3, 4, 6 and 10 stops in the 82MAG size in our range.
Variable ND: True Color ND-Vario at 1 to 5 stops, in 67MAG, 82MAG and 95MAG.
Polariser: True Color CPL.
Diffusion: Black Mist 1/4 and 1/8, Pure Mist 1/4, Glow Mist 1/4 and Black Magic Diffusion.
Special: Natural Night, UV/IR Cut and graduated ND.

Kits bundle an adaptor ring with a set of filters. The VND Flex and VND Mist Creative kits suit video, while the Landscape ND kit leans toward stills.

NiSi JetMag Pro kit, ring, mist and cap

Other magnetic systems in our range

System	How it mounts	Sizes	Worth knowing
NiSi JetMag Pro	Adaptor ring, magnetic filters, rotating lock	67MAG, 82MAG, 95MAG	Wide filter range including VND and mist
Freewell K2	Master base on lens rings	67, 72, 77, 82mm rings included	Reversible VND/CPL filters, slide-in gradients and mist
Freewell Magnetic Quick Swap	Base ring plus magnetic filters	Several thread sizes, including 67, 77 and 82mm packs in our range	Large set of single-purpose ND, mist and streak filters
PolarPro Helix MagLock	Threaded base plate, magnetic filters	Base plates 67 to 95mm	All Helix filters share one size and fit any base plate
Tiffen MCS	Magnetic adaptor ring	58, 77 and 82mm, step-up adapters for others	Filters ship with an adaptor and front and rear caps
Hoya Instant Action	Adaptor ring on lens, conversion ring on a screw-in filter	49 to 82mm	Turns filters you already own into magnetic ones

Freewell says the K2 works on a "thread once, work magnetically" basis. Its VND 1 to 5 filter turns over to become a CPL, and the VND 6 to 9 turns over to become an ND32 and CPL. PolarPro notes that Helix base plates can be combined with threaded step-up rings for lenses between the standard sizes. Hoya's approach suits anyone with a drawer of good screw-in filters: fit a conversion ring to each filter and an adaptor ring to each lens.

Freewell, PolarPro and Hoya magnetic options

Magnetic vs screw-in filter

Screw-in filters thread directly onto the lens. They are simple, secure and widely available, and most photographers already own some. The comparison comes down to how often you change filters.

	Magnetic	Screw-in
Changing filters	Seconds, no threading	Slower, threads can bind if overtightened
Stacking	Designed in, filters attach to each other	Possible, but thicker and slower to undo
Starting cost	Higher: ring per lens plus system filters	Lower: one filter per thread size
Sharing across lenses	Adaptor ring per lens, filters shared	Needs step-up rings to share
Mixing brands	Filters usually tied to one system	Any filter of the right thread fits
Security	Depends on the design; locks help	Mechanically fixed once screwed on

Filters from one magnetic system generally do not fit another, so you are choosing a platform rather than a single filter. Check that the range covers the ND, polariser and mist strengths you want before committing.

Screw-in Hoya and Tiffen filters

For a single lens and a filter that stays on for the day, screw-in remains the simpler choice.

Hoya UX II: Hoya calls it a basic filter with a 10-layer anti-reflective coating and water and oil repellent properties.
Hoya HD MkII: a 16-layer coating with water and oil repellent coating, sold as UV, protector and circular polariser.
Hoya Fusion Antistatic Next: an 18-layer coating plus an antistatic coating meant to repel dust.
Hoya Variable Density II: a variable ND that Hoya rates at 1.5 to 9 stops, with the caution that a cross pattern appears near maximum density.

Black mist filter: magnetic or screw-in

Mist filters are where the choice matters most, because many shooters use them only for certain scenes. Tiffen says its Black Pro-Mist reduces highlights and lowers contrast, but not as much as the regular Pro-Mist, keeping blacks black. It also softens wrinkles and blemishes. Tiffen notes that the effect becomes more apparent at densities of 1/4 and above, so 1/8 is the gentler starting point. If you put a mist on for a whole shoot, a screw-in Black Pro-Mist is fine. If you switch it on and off between shots, a magnetic mist such as NiSi's JetMag Pro Black Mist saves time, and soft effects and contrast filters lists both types.

Screw-in Tiffen and Hoya filters

Step-up rings and choosing a system

Step-up rings work with both approaches. With screw-in filters, a ring such as the NiSi Brass Pro 67-82mm lets one 82mm filter fit a 67mm lens. With magnetic systems, the adaptor ring often does the job itself: NiSi's 67mm-82MAG ring and Freewell's magnetic step-up ring 77-82mm both combine the step-up and the magnetic mount. Tiffen sells MCS step-up adapters for lenses outside its three native sizes. See all sizes in our step-up rings category.

A simple way to decide:

Choose magnetic if you shoot video in changing light, stack ND with mist or a polariser, or move one filter set across several lenses.
Choose screw-in if you mostly use one lens, leave a protector or polariser on all day, or want the lowest starting outlay.
Mix them with Hoya Instant Action if you already own quality screw-in filters and want faster changes.

For the exposure side, including how many stops you need and variable versus fixed ND, read our ND filter guide for video. Brand ranges are on the NiSi, Freewell, Hoya and Tiffen pages.

Questions

Do magnetic filters fall off?

Systems differ. NiSi's JetMag Pro adds a rotating lock on top of the magnets to hold multiple filters in place, and PolarPro and Tiffen design their base plates and adaptors as dedicated magnetic mounts. Check the filter is seated before moving the camera, particularly on a gimbal or when pointing the lens down.

Can I use NiSi JetMag Pro filters on different lenses?

Yes. Buy one adaptor ring per lens thread, all ending in the same MAG size, and share the filters between them. Our range includes 62mm, 67mm, 72mm, 77mm and 82mm to 82MAG rings. Keep the ring on each lens and move only the filters.

Are magnetic filters compatible across brands?

Generally no. NiSi JetMag Pro, Freewell, PolarPro Helix and Tiffen MCS each use their own mount, so filters from one system should be treated as fitting only that system. Hoya Instant Action is different because it adds magnetic rings to ordinary screw-in filters.

Is a black mist filter worth it for video?

It depends on the look you want. Tiffen says Black Pro-Mist reduces highlights, lowers contrast and softens skin while keeping blacks black. Start with a light grade such as 1/8 for subtle halation, and try 1/4 if you want the effect to be more visible.

Sources

Specifications and background were checked against these pages when the guide was last updated. Always confirm compatibility on the product page before ordering.

Magnetic ND Filter Systems vs Screw-In Filters

How a magnetic ND filter system works