Preston MDR

Technical Details

The MDR weighs 340 grams and measures 127 x 89 x 38 mm. Power is supplied via 12V or 24V DC with a consumption of 8 watts. The unit features three motor outputs, each with 12V/2A capacity, and RS-485 communication. The resolution is 16 bits per axis, allowing for 65,536 discrete positions. An integrated calibration mode (Lens Mapping) stores lens-specific parameters for up to 16 different lenses. The robust aluminum housing is IP54 rated for protection against dust and splashes.

History & Development

Preston Cinema Systems developed the first MDR in 1995 in response to the growing demand for wireless camera control in Steadicam and crane operations. In 2001, the MDR-2 followed with improved digital communication, and in 2008, the MDR-3 with zoom support. The current MDR-4 (2018) integrates ARRI and RED camera control via serial interfaces. Preston thus established itself as an industry standard alongside competitors like Arri cforce and Teradek RT.

Practical Application in Film

On "Gravity" (2013), MDR systems enabled precise focus pulling during complex LED wall sequences. "1917" (2019) utilized the system for seamless focus pulls during its seemingly uncut camera movements. The typical workflow involves calibrating the lens on set, mapping focus marks, and subsequent wireless control by the focus puller. The response time of under 20ms makes jerky movements practically invisible, while the high resolution allows for precise work even with long focal lengths.

Comparison & Alternatives

In contrast to the more affordable Teradek RT motor, the MDR offers more robust mechanics and more precise calibration. The Arri cforce system scores with seamless integration into Arri cameras but does not achieve the universality of the Preston system. Modern alternatives like the DJI Focus Pro offer similar functionality at lower costs, while high-end productions continue to rely on proven Preston technology. The choice depends on budget, camera system, and desired precision.