What the thread found

• The Arriflex Master Zoom cannot be properly mapped to a Preston HU3 because it features non-linear focus characteristics
• RED Pro Prime lenses from 18mm to 100mm are incompatible with HU3 mapping
• A lens can be identified as non-linear during calibration when the six reference marks are accurate but intermediate focus positions are incorrect
• Some RED Prime lenses can be partially calibrated by adjusting the close focus starting point, though this requires manual adjustment of subsequent marks
• Panavision G series anamorphic prime lenses up to 100mm require custom marked rings rather than the standard pre-marked HU3 rings
• Panavision E series 135mm and 180mm anamorphic lenses work correctly with standard pre-marked HU3 rings

Depends on

• The workaround for RED Primes involves guessing the final calibration mark and may not achieve perfect accuracy at distances closer than the adjusted close focus point
• This discussion is specific to Preston HU3 follow focus systems
• No explanation was provided for why specific lens designs cause non-linear focus behavior
• The status of Preston's investigation into RED Prime compatibility was unresolved at the time of discussion

Gear in this thread

HU3

Parts

Follow Focus

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