Tilta Khronos Magnetic 58mm Variable ND Filter (2-5 Stops) - Black

The Khronos Magnetic 58mm Variable ND Filter (2-5 Stops) (Black) takes 2 to 5 stops of light out, continuously. Its 58mm diameter covers all three iPhone cameras at once. The filter snaps magnetically onto the Khronos 58mm filter tray, which slides into the slot of a Khronos or Khronos Lite case for iPhone 17 Pro and Pro Max — neither the tray nor the case is included.

Khronos Magnetic 58mm Variable ND Filter (2-5 Stops) — Black.

A 2-5 stop range

Turning the front ring changes the density continuously between two and five stops. In optical density that is ND 0.6 to ND 1.5, or ND4 to ND32 in the common notation — from 1/4 of the light down to 1/32.

What it is for

The iPhone controls exposure mainly with shutter speed, which is a problem for video: in midday sun it pushes the shutter into thousandths of a second and the footage looks stuttery. A variable ND takes the light away before it reaches the sensor, so you can keep the shutter at twice the frame rate (the 180° rule) and motion keeps its natural blur. Moving from shade into sun, you dial the density instead of swapping filters.

58mm diameter

The 58mm glass covers all three iPhone cameras at once, so the filter still applies after switching to the ultra-wide or the telephoto. Colour rendition stays neutral, without the colour cast typical of cheap variable ND filters.

How the filter gets onto the phone

The filter does not attach to the phone directly. It snaps magnetically onto the Khronos 58mm filter tray, and that tray slides into the dedicated slot of a Khronos or Khronos Lite case. The tray is tied to the phone model — one for iPhone 17 Pro, another for iPhone 17 Pro Max. Neither the tray nor the case is included with the filter.

Do not confuse the two trays: the Khronos quick release filter tray is made for the rectangular Khronos magnetic filters (FSND, Black Mist, White Mist) and this circular 58mm filter does not belong on it.