Preston HU-3 & HU-4
Connecting Moon Smart Focus to Preston HU-4 (and HU-3 )
Connect the Moon Brain to your MDR’s serial connector using the custom cable MSF.C40.02.
Then, choose the Preston protocol for Lens Control System in the Moon App.
Moon Smart Focus is compatible with:
- Preston HU-3 / HU-4
- Preston MDR-3 / MDR-4
(MDR-5 pending testing)
For best results, use MDR-4 for reliable focus tracking.
Focus tracking may work with MDR-3, but performance can vary by hardware revision.
If only an MDR-3 is available, test focus tracking functionality during prep — or contact Preston to confirm that you have the latest hardware.
Moon App Setup Steps
- Open Settings in the Moon App (double-click the bottom-right button).
- Go to Connections → Setup → Lens Control System.
- Set Protocol to Preston.
- Set Connector to Moon Serial Connector.
On the Hand Unit
Once connected, you’ll see “Cinetape” displayed — this is normal and indicates communication success.
In the Moon App, an AUTO button appears for toggling focus tracking on or off.
Indicators in the App:
- Small green arrow (left): focus knob position
- Yellow (when AUTO on): indicates manual override disabled
- Large green arrow (right): distance measured by Moon
- Small white arrow (opposite): distance sent to Preston system
Optional: Bluetooth Control
Moon Smart Focus is currently testing third-party Bluetooth buttons that can toggle focus tracking directly from your hand unit.
Contact support if you’d like to join the beta program.