Khronos Magnetic FSND 1.8 Filter for iPhone

The Tilta Khronos Magnetic FSND 1.8 filter for iPhone cuts 6 stops of light, i.e. ND64. Even in harsh sunlight it lets you hold a 1/50 s shutter and natural cinematic motion blur, or stretch the exposure for stills. Multi-coated optical glass attenuates every wavelength evenly — visible light, UV and infrared — so colours stay true. The filter drops magnetically into the Khronos filter tray. Space Gray finish.

The Khronos FSND filters are flat, magnetically mounted glass that hands exposure control back to the iPhone. In bright light the phone cuts brightness by shortening the shutter, and the video turns choppy; with an ND filter you can shoot in midday sun at a 180° shutter angle — 1/50 s at 25 frames per second — and motion stays smooth. In stills the same density opens the door to long exposures, silky water or streaked clouds.

The number on the filter tab is the optical density. Most people look for “ND8” or “three stops” instead — here is the conversion:

The filter is a single piece of glass covering all three iPhone lenses. It aligns to the guide slot in the Khronos filter tray and a magnet holds it, so a swap takes a second — even mid-take. The tray clicks onto the quick-release points of the Khronos case, locks with an anti-rotation clip and swivels through 180°.

You need the Khronos case for iPhone and the Khronos Quick Release Filter Tray to use it. Neither is included with the filter, and without them the filter will not stay on the phone. Tilta lists the filters for iPhone 15 and 16 Pro / Pro Max. One filter goes into the tray at a time — the manufacturer does not describe stacking several filters.

Key features

• Multi-coating limits reflections and lens flare
• Protects the lenses against scratches, smudges and debris
• True colour rendition with no colour cast
• Full-spectrum ND: even attenuation of visible, UV and infrared light
• Far thinner and lighter than conventional screw-in filters