ADVERTISEMENT FEATURE
Lighting in the volume Richard Mead, CEO at Brompton Technology, advises on achieving better colour rendition for ICVFX
O ne of the key benefits of shooting a scene within a virtual production LED volume is the realistic reflections and lighting from the LED panels themselves. This is such an important element of achieving realistic in-camera visual effects (ICVFX) that many volumes have LED ceilings or flanking walls never in shot, solely to contribute to the lighting of the scene. However, RGB panels we use today are great for direct view, but not for lighting a scene. Their spectral output is different from normal lighting sources, so skin tones in particular can look unnatural and some colours are shifted. The red, green and blue emitters in an LED panel are intentionally selected to have a narrow spectral output around the target wavelength. This is essential to achieving a wide colour gamut and accurately reproducing saturated
colours, but different from the spectral output of a typical light source, which will be very broad with output across all visible wavelengths. If things within your scene reflect light primarily in the yellow- orange colours, there is little light energy present at those wavelengths. Things will either look more red or more green than they should – a colour shift. Crucially, most skin tones fall in this range, and so faces look flushed and unnatural when illuminated by light from an RGB panel. This is of critical importance for in-camera visual effects, which rely on achieving consistency between colours in foreground ‘real’ elements and the virtual background.
WHEN YOU’RE DISPLAYING RGB video with RGB emitters , THERE IS one right answer ”
RGB vs RGBW Adding an additional white LED emitter to every pixel (RGBW) offers a potential
solution. With a white LED boasting a broader spectrum, it emits light across all wavelengths, ensuring natural-looking
48
DEFINITIONMAGAZINE.COM
Powered by FlippingBook