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Flicker-Free Filming
The only way to guarantee flicker-free
filming at any frame rate and shutter
angle is by using pure DC power,
carbon arc sources, or daylight. There
is a chance of flicker in every other
scenario with artificial light, even with
tungsten mains-powered fixtures.
Visible flicker is also affected by
postproduction. Where the contrast is
increased, the flicker becomes more
visible.
ALLEGRA-C™ has been validated
flicker-free at any dim position up to
10,000 fps. ALLEGRA-C™ has been
tested across a range of dim settings,
CCTs, and colours with the high-speed
Vision Research Phantom camera
as well as Arri Alexa Mini, with the
cameras at multiple shutter angles. Not
all manufacturers are as thorough. Test
whenever in doubt, particularly when
shooting high speed.
PANALUX ALLEGRA-C USER MANUAL
Flicker factor, the relationship
between the maximum and minimum
illuminance exhibited in the flicker, can
be measured with a flicker meter. 100%
means the light goes totally dark at
minimum. HMI electronic ballasts tend
to have a flicker factor around 1–3%,
tungsten lights 0–10%.
With multi-colour LED fixtures, in
particular older Stage and Architectural
LED fixtures where compatibility with
film and digital cameras wasn't a
consideration in their design, individual
colour channels can be out of sync,
causing different colour mixes on
different frames, which can cause
issues with high-speed filming, stop-
frame animation, and still photography.
If in doubt, test and review. Check the
footage after running a test, and be
aware that some digital cameras do not
replay raw footage, so it is advisable to
download files first and then check.
7
Gel/Filter Emulations and
Source Matching
ALLEGRA-C™ comes pre-loaded with
a range of LEE Filter gel emulations.
Since the base spectrum of the
ALLEGRA-C™ at 3200K and 5600K is
not identical to a tungsten or daylight
source, the gel presets are merely
emulations. Due to the inherent
technology, no LED bi-colour or multi-
chip source can perfectly match the
spectrum of a subtractive filter laid
over a tungsten or daylight source.
Even if the x y coordinates appear to
be a good match, the spectrum will
be different, and the camera will read
subtle differences. If in doubt, test
before shooting.
ISSUE 1.0 | OCTOBER 2023
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