NiSi True Color Variable ND 4x5.65: 6mm vs 12mm Matte Box Guide

Quick answer

Choose the 6mm version if your matte box has a single filter slot and you use small lens motors; choose the 12mm version if you have two slots and large motors. Mount either filter in a 4x5.65 matte box, attach the focus control gear to your motor, and calibrate the 1–5 stop range before shooting.

Step-by-step matte box setup

1. Check your matte box slot count and motor size: Count the available 4x5.65″ filter slots and measure the thickness of your lens motor. If you have one slot and a motor up to 6mm thick, use the 6mm version. If you have two slots and a motor up to 12mm thick, use the 12mm version. If your motor is thicker than 12mm, neither version will fit without a different gear. Write down your slot count and motor thickness before ordering.
2. Insert the filter into the correct slot: For the 6mm version, slide the filter into a single slot. For the 12mm version, use two slots as designed. Do not force the filter into a slot that is too tight; it should slide smoothly without wobble. A filter that binds can damage the matte box or the filter edges.
3. Attach the focus control gear to your motor: Mount the gear on the filter’s edge and connect your lens motor. The 6mm version accepts small motors up to 6mm thick; the 12mm version accepts large motors up to 12mm thick. Ensure the gear teeth mesh fully and the motor is supported by the included 15mm support rod. A partially engaged gear will slip and cause uneven density changes.
4. Calibrate the stop range: With the motor connected, run the filter from minimum to maximum density and note the motor’s position readout. The 12mm version has stop marks on the gear to help you repeat settings; on the 6mm version, mark your own reference points on the motor controller if needed. Test the full 1–5 stop range before the first take to confirm the motor does not strain at either end.
5. Set exposure and verify with a monitor: Start at the minimum density (1 stop) and increase until your highlights are protected. Check the image on a calibrated monitor or waveform; do not rely on the filter’s markings alone because the actual density depends on your lens and lighting. If you see a color shift, reduce density slightly or check that the filter is seated flat.

Product facts

• NiSi Cinema 4×5.65″ (6mm) True Color Variable ND 1-5 Stops (0.3-1.5) Filter: Variable 0.3–1.5 Neutral Density filter reduces exposure by 1 to 5 stops and uses a single slot in a 4 x 5.65″ matte box. If your matte box has only one free slot, this version keeps another slot available for a polarizer or other filter.

  

• NiSi Cinema 4×5.65″ (12mm) True Color Variable ND 1-5 Stops (0.3-1.5) Filter: Features a focus control gear with stop marks and supports large lens motors 12mm in thickness. Stop marks help you return to a previous density quickly, which is useful when lighting changes between takes.