ND Filter Test from John W. Rutland

John W. Rutland nuts out an ND quality test or two, trying out the Tiffen IR ND, Schneider Platinum IR ND, Mitomo True ND, & Formatt Firecrest IR ND, as well as internal ARRI Alexa Mini ND filters.

ND FILTER TEST // from JOHN W. RUTLAND on Vimeo.

There are three things that annoy me about ND filters:
1) Color shift between different densities of ND filters
2) Light transmittance that is different than what it should be (ND.3 = 1 stop / ND.6 = 2 stops / ND.9 = 3 stops / ND1.2 = 4 stops / ND1.5 = 5 stops / ND1.8 = 6 stops / ND2.1 = 7 stops)
3) Color shift between two different sets of the same brand of ND filter

This is a test that evaluates the first two items on this list with 4 different brands of ND filters as well as the internal ND filters on the Arri Alexa Mini. The 4 brands I tested were Tiffen IR ND, Schneider Platinum IR ND, Mitomo True ND & Formatt Firecrest IR ND.

TRANSMITTENCE DATA //

WHAT IT IS SUPPOSED TO BE:
ND.3 = 1 stop
ND.6 = 2 stops
ND.9 = 3 stops
ND1.2 = 4 stops
ND1.5 = 5 stops
ND1.8 = 6 stops
ND2.1 = 7 stops

(These readings were taken by placing the filter completely over the flat ball of my Spectra light meter. I double checked each time that I was getting an f22.0 on my meter before placing the filter over my meter)

TIFFEN IR ND:
ND.3 = .9 stops
ND.6 = 1.9 stops
ND.9 = 2.7 stops
ND1.2 = 3.2 stops
ND1.5 = 3.7 stops
ND1.8 = 4.1 stops
ND2.1 = 4.3 stops

SCHNEIDER PLATINUM IR:
ND.3 = .7 stops
ND.6 = 1.8 stops
ND.9 = 2.5 stops
ND1.2 = 3.5 stops
ND1.5 = 3.7 stops
ND1.8 = 4 stops
ND2.1 = 4.1 stops

TRUE ND:
ND.3 = 1 stop
ND.6 = 2.1 stops
ND.9 = 3 stops
ND1.2 -= 4.1 stops
ND1.5 = 5.2 stops
ND1.8 = 6 stops
ND2.1 = 7.1 stops

FORMATT FIRECREST:
ND.3 = 1 stop
ND.6 = 1.8 stops
ND.9 = 3.3 stops
ND1.2 = 4.2 stops
ND1.5 = 5.5 stops
ND1.8 = 6 stops
ND2.1 = 7.3 stops

TEST DATA //

Camera: Arri Alexa Mini
ISO: 800
Lens: 75mm Zeiss / Arri Master Prime
T Stop: T2.0 (This varied to compensate for transmittance of the ND filters. I kept the white chip on the gray card at the same IRE on my waveform.)

Leave a Comment Here

comments