The ND answer says STACK

Past seven stops there is no single filter in the ND 0.3 to 2.1 range, so Meter names a STACK with the total density, to build from two or more filters.

Step by step

1. Read the total density after STACK, for example STACK 2.7.
2. Build it from filters that add up to it, such as 1.2 and 1.5.
3. Or open RIG and solve for the stop, ISO or shutter to bring the ND back into range.

If that didn't work

Densities add when you stack filters. If Meter says no filter adds light, the scene is darker than your settings expose for, and there is nothing to take away.

Go further

• ND calculatorFree tool

Last updated November 2, 2026