Tungsten light flicker when shooting with Arriflex 16S wild variable motor

[Ivan DImitrov Alexandrov]

Hello, I will be shooting in Europe under 50hz with Arriflex 16S with the original wild variable motor. Im worried that by shooting at 24fps 180° I will get flicker with 650w tungsten lights. I don’t know if I should shoot at 25fps, or the motor is so inaccurate it wouldn’t make a difference?

[Sebastian Bock]

Real tungsten light shouldn’t be a problem. Only fluorescents, cheap LEDs and HMI without electronic flickerfree ballasts. 

So many productions have been filmed with the ARRIFLEX 16 in the last century with the wild motor without flickering…

Edited January 27, 2024 by Sebastian Bock

[Simon Wyss]

The Arriflex 16’s shutter opening angles are 85 degrees, so 170 degrees per frame.

Tungsten incandescent lamps don’t flicker due to the hot filament that doesn’t cool down between phase pulses.

[Ivan DImitrov Alexandrov]

25 minutes ago, Simon Wyss said:

The Arriflex 16’s shutter opening angles are 85 degrees, so 170 degrees per frame.

Tungsten incandescent lamps don’t flicker due to the hot filament that doesn’t cool down between phase pulses.

Interesting, I always thought it was 180°

[Sebastian Bock]

According to the original manual it is 180°

[Brian Drysdale]

Although not an Arri, years ago, I shot with a Bolex H16 that had a flicker issue because of damage to the drive shaft that the external motor was attached to. The motor worked fine on a different camera.

[Ivan DImitrov Alexandrov]

2 hours ago, Simon Wyss said:

The Arriflex 16’s shutter opening angles are 85 degrees, so 170 degrees per frame.

Tungsten incandescent lamps don’t flicker due to the hot filament that doesn’t cool down between phase pulses.

Wouldn’t tungsten fixtures below 2000w flicker a bit? Or is it only noticeable at high speeds?

[Mark Dunn]

20 hours ago, Ivan DImitrov Alexandrov said:

Wouldn’t tungsten fixtures below 2000w flicker a bit? Or is it only noticeable at high speeds?

As Simon says, the brightness of the filament does not vary very much on a 50hz supply. I have shot at 10,000pps with tungsten lighting and the flicker was not noticeable. If you want to check it, you could try high-speed video on your phone, or an app such as Video Tachometer set to a high frame rate.

The difference between a 180 and 170 degree shutter is insignificant.

Edited January 28, 2024 by Mark Dunn

[Ivan DImitrov Alexandrov]

7 hours ago, Mark Dunn said:

As Simon says, the brightness of the filament does not vary very much on a 50hz supply. I have shot at 10,000pps with tungsten lighting and the flicker was not noticeable. If you want to check it, you could try high-speed video on your phone, or an app such as Video Tachometer set to a high frame rate.

The difference between a 180 and 170 degree shutter is insignificant.

I checked with my phone and the the 650w light, and it seems only to flicker noticeably at 120fps onwards.