On 08/08/2012 02:47 AM, Graeme Gill wrote:
Ernst Dinkla wrote:
It is different for point light sources where a high CRI number is needed, replacing halogens, tungsten and CFLs with LED designs should be possible in time.
White LEDs based on blue + phosphor have an aging problem - they go green as the phosphor ages. White LED based on RGB are (by definition) three narrow band illuminants, and probably also change white point as they age (although this could be compensated for). Creating a high quality (ie. like sunlight) illuminant using LED's would seem to be non-trivial.
Graeme Gill.
Well the first experiment with a full spectrum white light, Quantum Dots covered LED, was almost a DIY job :-) I gave you the link: http://www.vanderbilt.edu/exploration/stories/quantumdotled.html The QDs show less energy loss than several fluorescent layers do. I am more optimistic about full spectrum white LED development, it may even be an LQD if their approach to feed the Quantum Dots directly with energy works, bypassing the UV light of the LED. My question remains though; the best CRI FLs still must have some flaws, on which patches of the CRI table, R9 as well ? -- Met vriendelijke groet, Ernst Dinkla Grafische Techniek Quad, piëzografie, giclée www.pigment-print.com