for 15 mm Lightweight Support - designed with light
er cameras in mind and compatible with all available
ARRI lens gearsand focus knobs.
Cine has a gear ratio of 2:1 for cine style lenses,
which means one turn of the focus knob will result
in two turns of thefocus gear. This gear ratio is common
to all classic follow focus units from ARRI (FF-3, FF-4, etc.) and
is traditionally suited to cine lenses such as Ultra Primes,
Compact Primes, Alura Zooms, Angenieux Zooms, etc...
 
HD has a slower gear ratio of 1:1 for 2/3” broadcast
and still photo lenses. In this case, one turn of the focus knob will
result in a single turn of the focus gear. This particular
gear ratio might bepreferred when using lenses with a short focus
throw, where the scale from minimal focus to infinity is so short that a
traditional 2:1 ratio could be too direct, lacking
in precision. Typical lenses suited to the HD ratio
are modern still prime lenses, some ENG zooms, extreme wide-angle lenses
or some older designs.
For Marking Disks please see chapter inchMarking Disks
for Follow Focus inch