Motorised Polariser for Bentley automotive commercial
Cinefade is a variable depth-of-field effect that uses a motorised polariser and a static polariser, which together form a variable ND filter. The motorised polariser can also be used independently as a ‘RotaPola’ that has end stops for easy calibration, allows users to set marks and can be controlled remotely, which sets it apart from similar products such as the Tiffen Multi Rota Tray or ARRI’s Rota Pola frame.
BEHIND THE SCENES WITH BENTLEY
Watch the short BTS film to see how the Cinefade Motorised Polariser was used on set at Junction Eleven Studios.
CINEFADE MOTORISED POLARISER
The Cinefade Motorised Polariser is a filter tray that holds a custom Schneider polarising filter. The filter tray has a motor mounting point on the handle so that a typical lens motor (Arri CLM5, cmotion cforce etc.) can be mounted directly onto the tray without the need to build a complicated rig from the camera.
In addition, the tray has built-in mechanical end stops, which limit the rotation so that the filter does not continuously rotate, which allows for easy and fast calibration with a lens control system.
MOTORISED POLARISER TO CONTROL REFLECTIONS
Polarising filters allow cinematographers to control reflections, such as those in glass windows and cars’ bodywork.
Director Paul Griffin was able to precisely control the reflections on the Bentley Mulsanne’s front windscreen and together with the client decide on how much of the interior to reveal.
Since the polariser can be remotely controlled, Paul was able to dial in the amount of reflections himself with a hand unit and make a decision with the client standing by the monitor.
MOTORISED POLARISER FOR PLATING SHOTS
In order to have complete control over the look of the car and how the light reacts with the bodywork in post-production, Director Paul Griffin shot several takes of the same setup, changing only the angle of the polariser in 10 degree increments.
Having calibrated the filter motor, 1AC Oliver Janesh Christiansen was able to set marks on the hand unit indicating the exact position of the polariser and quickly run through the all 10 positions from 0 to 90 degrees.
During post-production, Paul could choose his favourite part of each frame and stitch them together to create a beautiful final image. Tricky reflections that would have taken time to re-light on set could be eliminated quickly for the composite image.
MOTORISED POLARISER TO ANIMATE POLARISATION EFFECT OVER TIME.
A polariser drastically affects the way light reflected from cars hit the camera’s sensor, so that the metal bodywork can be anywhere between being very reflective and looking almost white to being completely black.
The Cinefade Motorised Polariser is controlled with a lens control system, which allows the polarisation effects to be smoothly animated over time by rotating the polariser through the full 90 degrees over several seconds. This results in a unique and interesting effect.
WATCH EXAMPLES OF THE POLARISATION EFFECT
MOTORISED POLARISER ON RUSSIAN ARM
The motorised polariser comes in useful whenever the camera is inaccessible, for example on a Russian Arm. Using the Cinfeade motorised polariser to film cars with such a setup allows the DP to control reflections remotely and to keep the reflections consistent throughout a shot for example when the car is going around a corner and the angle of the light changes the polarisation effect.
Other applications include helicopter and drone setups, as well as gimble setups.