To view this page ensure that Adobe Flash Player version
11.1.0 or greater is installed.
tempting to use lights with a green
spike for example (Architectural or
non-Kino Flo fluorescents or cheap
LED sources) and this may work
well if controlled correctly (it can
also reduce the amount of light
needed) however most shooting
environments are in constant flux
and unless you are renting or using
the fixtures for a single purpose or
set up, contamination (especially on
skin) can be a major issue in pulling
a clean key.
Green is your enemy - If producing
high quality images is our aim, we
need to take real care of skin tones,
but we need to ensure we can easily
pull off detail like hair convincingly.
In order to do this we need to work
to keep all green light including spill
and bounce light confined to the
screen area itself. We need to be
aware of the psychology of colour
on the human - Green denotes the
colour of illness and or decay and it
is a colour we should not really use
on skin. It creates a sickly looking
person that is not pleasing to the
eye. High quality skin tones make
images look glossy.
Fighting Green - There are times
when contamination cannot be
avoided generally due to lack of
space. In this situation some minus
green gel (magenta) on the back
lights can counter the contamination
and do a great job of helping to
provide that clean problem free key.
But an issue may arise when you put
the background in as you will see a
magenta rim around your subject in
the foreground, so beware.
Summary The art of pulling a good matte
is the careful and full analysis
of the foreground subject and
the background to be inserted.
Recording as much resolution
and digital information that the
edit system may need, including
recording at a 4:2:2 sub-
sampling compression ratio or
better and lighting the foreground
sympathetically with the light in the
background. Lighting the green
or blue screen evenly and at an
exposure level of 1 F-stop below
the foreground, and placing the
camera at a correct orientation as to
create a foreground image that sits
seamlessly into the back ground.
If you can achieve all this, you will
find the postproduction processes
a pleasure and the illusion will be
seamless and complete.
David Morphy is the technical director and one of the founding partners
at Cirro Lite a company renowned for its technical innovation and
market leading solutions. David has been involved in high end lighting
technology for over 30 years, he started his career in the music industry
working with visually creative acts like Pink Floyd, Genesis and the
Rolling Stones. In 1992 he started Cirro Lite with John Coppen to
promote new technology with the aim of launching Kino Flo in Europe,
his first major screen job was for ILM (George Lucas) who were
contracted to do the special effects for the “Helicopter in the tunnel”
sequence on the first Mission Impossible film on the 007 stage in
Pinewood. For this Sequence ILM insisted that a plane full of Kino Flo
units loaded with Spiked Blue 420nm bulbs to light the screen in order
to hit the release date for the feature. This was a first in Europe and the
start of a whole new wave of digital effects work now common place in
the industry. David brings this knowledge and more to the creative use
of light in image creation.
TV-BAY MAGAZINE | 77