Radio frequency band selection and power output for wireless follow focus systems

2007Follow Focus forum

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

DisputedParticipants disagreed and reached no conclusion. Read the findings as positions, not as an answer.

Follow focus systems operate on different frequency bands: 434 MHz, 900-928 MHz, and 2.4 GHz microwave, each with different range and interference characteristics.
Lower frequency bands like 434 MHz experience interference from higher-power devices such as car keys, security intercoms, radio microphones, light dimmers, and ticket readers that occupy the 400-800 MHz spectrum.
The 2.4 GHz Preston system operates at approximately 1 kilometer line-of-sight range but competes with WiFi transmitters and wireless camera control systems on the same frequency band.
Higher frequency does not automatically provide longer range; range is inversely proportional to frequency, so 10 milliwatts at 2.5 GHz does not deliver ten times the range of 1 milliwatt at 900 MHz.
FCC Part 15 compliance limits the BFD system to 1-2 milliwatts output, providing roughly 300 feet (100 meters) line-of-sight range and penetrating through multiple walls.
Concert venues and large events create crowded RF environments with powerful transmitters that can jam wireless follow focus systems regardless of frequency band chosen.
The 900 MHz band was historically abandoned due to overcrowding but later had less interference as users migrated to 2.4 GHz frequencies.
The 2.4 GHz band experienced interference problems during a Paris shoot where multiple Preston systems and other 2.5 GHz devices created jamming issues.

Discussion is from 2007; current frequency allocations and device populations may differ significantly.
No technical specifications provided for Bartech system output power, only frequency range mentioned.
Claims about Preston system 1 km range are questioned by forum participants and not definitively confirmed.
Specific interference problems described are anecdotal and tied to particular concert venues and event setups rather than systematic testing.
Solutions proposed were not conclusively resolved in the thread.