SteadiHub
2011Follow Focus forum

Arri UDM-1 ultrasonic distance measurement device for follow focus applications

15 years old. Gear and prices may have changed since.

What the thread found

  • The UDM-1 measures distance using ultrasonic signals reflected from objects and displays results on an LCD screen in feet/inches or metric units.
  • The device integrates with Arri's lens control system to enable autofocus capability when connected to their LDS data system.
  • The LCD display exhibits poor visibility when viewed at angles, making it difficult to read from certain positions on set.
  • LED-based displays with red backlighting would provide superior visibility compared to the LCD implementation used in this model.

Depends on

  • Discussion compares the UDM-1 against CineTape but does not provide complete technical specifications for direct comparison.
  • The LCD visibility issue is described anecdotally rather than through detailed measurement or testing.
  • No information provided about whether the offset feature gap versus competitors affects actual follow focus performance.

Parts

Follow Focus

Same gear or parts

  1. 2026Pulling focus and zoom yourself while operating, especially on live showsOperator practice
  2. 2026Swapping an ARRI ALEXA 35 between tripod/studio and Steadicam® mounting: baseplate choice and fastest workflow.FacebookSteadicam operators group
  3. 2025LC-1 (Lens Control-1) follow focus system: wired architecture, motors, and early operational experience (1990s).FacebookThe Steadicam Group
  4. 2024Modifications to a Steadicam Scout rig for expanded power distribution and connectivityGeneral Discussion
Read the original threadAsk about this threadThe answer cites the archive