Arri ESU-1 External Synchronization Unit for Arri Alexa

Fri Sep 03, 2021 11:14 am

Dear Alexa forum,

I will be shooting a scene with an old CRT monitor (taken from an Philips X-ray machine, looks like from the 80s maybe). I will use an Arri Alexa Plus Classic and the film is generally shot in 24.000fps.
We are planning to replace the content of the screen in VFX but still, I would like to use the screen as a light source, to realistically emulate the light coming from it. The CRT should be PAL and the electricity supply network is on 50hz.
Now I am wondering if in order to prevent any flicker I should arrange a sync / phase control box like the Arri ESU-1. Do you know if such a thing exists for the Alexa, too? Do you think it’ll be necessary?
I’ll do a test with the camera and the screen at the rental probably at the beginning of next week and know more, but I’d like to be prepared (maybe I could arrange such a sync box before the test).

Kind regards, Tilmann
Posts: 1
Joined: Wed Sep 01, 2021 11:31 am

Re: Arri ESU-1 External Synchronization Unit for Arri Alexa

Mon Oct 04, 2021 9:51 am

Dear Tilman,

"a bit late" but here's the answer to your question:
the ESU-1 is for film cameras only hence it will not work with ALEXA.

Alexa has the option to define a user button for "phase sensor":
This function temporarily shifts the sensor frame rate for 0.2 fps as long as the user button is pressed in order to adjust the phase of the ALEXA frame rate to an external de- vice, i.e. a CRT monitor or a rear screen projector.
Only available in standby and with time- code in rec run

Which should do the trick.

Jan Heugel
Application Engineer
Jan Heugel
Posts: 424
Joined: Wed Aug 13, 2014 3:15 pm
Location: Munich, Germany

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