The issue, though, has been in matching LEDs to the well-known light profile
of tungsten bulbs, which the industry had thought it had solved. In the U.K.,
the BBC has been experimenting with LED lighting for production for more than
three decades, and has recently used it on the sets of popular shows such as the
hospital drama "Casualty." The BBC says it has led flood light developed tests that assess the
color rendition of low energy light sources, and has stated it wants to send a
clear message to the broadcasting community and to its viewers about the leading
role that LEDs play in sustainable low energy production helping meet targets
for reduced carbon emissions.
There has been similar enthusiasm for studio LEDs elsewhere, and they have
been used in the U.S. for filming popular prime-time reality TV competitions
such as "Dancing with the Stars," "America's Got Talent" and "American Idol.But
now the EBU suggests it may be premature to embrace LEDs fully in the studio,
even if they are now ready for the home. Problems that have been identified
include inconsistencies between factory batches, insufficient brightness and
inability to spotlight subjects, especially from a great distance. A further
issue is that color LED lights are prone to color shifts and inconsistencies
that can be especially evident when lighting people's faces.
The EBU is not suggesting broadcasters should avoid LEDs, but urges them to
recognize that many new LED lights fail to perform as well as had been expected
or promised. The EBU has come up with its own recommendation to help
broadcasters assess how well their television lighting performs. Called R 137,
and accompanied by a software-based analysis tool, this is led high bay light designed to quantify
how well a set of test colors is reproduced when illuminated under a given light
and viewed through a standardized camera and TV system. The software compares
the differences in colors produced by the light source under test with those
rendered under standard lighting conditions. It assigns a value from 0 to 100 to
each light tested, and that value gives an indication of how much color
correction would be required to produce acceptable results with that light.
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