American Cinematographer - August 2017 - 18

Chambliss. "Safety Bulletin #36 by the
Joint Labor-Management Safety Committee is an excellent start. Going beyond
that, we're encouraging the community
to develop a set of operational standards
that would be applicable across all sets."
On the East Coast, Corey Bracone
and an ad-hoc committee of drone
specialists are part of that effort to
develop a best-practices handbook and
are pushing for easements in NYC-specific
restrictions. That advocacy work is as
much a part of their nascent business as
the fleet of five drones that Bracone and
his brother fly. They consider it a necessary
investment in their future. Once the dust
settles, he says, "We're ready to go!"

Tech Essentials
Drone Primer
Drones have become a hot new tool
in imaging. What was previously the
purview of helicopters armed with gyroscopes - or, worse, operators hanging out
open helicopter doors - is now becoming
the task of unmanned copters of all sorts.
UAS (unmanned aerial system) or UAVs
(unmanned aerial vehicles) have become
increasingly popular for all kinds of image
capture, from news gathering to feature
filmmaking. Although some may find these
drones a nuisance, they afford the opportunity to achieve dynamic shots in a signifi-

August 2017

The Fault in Your CRIs
By Jay Holben
For lighting professionals, CRI -
color rendering index - is a ubiquitous
term. Most everyone is at least somewhat
familiar with the scale, which runs from 0100, and knows that the closer you get to
100, the better color fidelity your fixture will
have.
But let's take a closer look.
The International Commission on
Illumination, otherwise known as the CIE
(Commission Internationale de l'Eclairage),
invented CRI as a methodology for determining the comfort levels for human beings
around non-continuous-spectrum light
sources. It was first published in 1965 after
fluorescent lights had started to become

cantly safer manner than ever before.
In the world of motion-picture drones
- not to be confused with sporting
or racing drones - companies such as
DJI, Freefly Systems, Shotover, Gryphon
Dynamics, Traxxas, Autel Robotics, Yuneec
and Xiaomi make aircraft suitable for
image capture. All of them require a delicate
hand to control, and require registration
with the Federal Aviation Administration
(registermyuas.faa.gov) before piloting. All
of these models are governed by FAA regulations, and it's the responsibility of the pilot
to follow those regulations and maintain a
safe flight at all times.

American Cinematographer

Some general tips for drone piloting:
* Get to know the laws in your area before
piloting
* Practice makes perfect - drones are
delicate and require considerable time to
operate properly, safely and effectively
* Always follow a preflight checklist
* Know your hardware, its flying modes
and functions
* Slow and steady nearly always does it
* Never overshoot your flying time
* Avoid wind, rain and other inclement
weather
* Plan your shots carefully
* Maintain direct sight whenever possible
- Jay Holben

CRI images courtesy of Jay Holben.

The original eight color patches in the CRI test protocol (top) were a somewhat random
selection of pastel colors. The six extended patches (bottom) add saturated red, green, blue
and yellow, along with yellow-pink and greenery.

widely used. CRI was designed for architectural applications in locations - shopping
malls, restaurants, airports - that would
benefit from the high efficiency and long
lives of non-continuous-spectrum sources
such as metal-halide gas discharge and
fluorescent lighting.
In the 1980s - with a great deal of
thanks to Frieder Hochheim, who would
later found Kino Flo and is now an ASC
associate member - the humble fluorescent fixture became a viable tool for the
motion-picture industry. Hochheim struggled for several years to come up with the
right alchemy of phosphor coatings in his
tubes that would produce solid, correlated
color-temperatures and a high-enough CRI
for photography.
CRI has been used since the 1970s
with HMI fixtures as well, again to identify
the color fidelity of a light source. Indeed,
despite some inherent shortcomings of CRI
and the fact that the system was never
designed for photographic applications, it
has been widely adopted, with every manufacturer of a non-continuous-spectrum light
source testing and reporting the CRI of their
fixtures.
Enter the 21st century and the lightemitting diode (LED) technology that has
suddenly become viable for use in photography. In keeping with established tradition,
the manufacturers of those LED fixtures of
course reported their CRI ratings - many
of which were super-high, at 95 and above.
But testing the fixtures revealed that those

http://registermyuas.faa.gov

Table of Contents for the Digital Edition of American Cinematographer - August 2017