Comment by lowkey | Hacker News Reader

Comment by lowkey | Hacker News Reader

Parent Full thread

Funny, I am a co-founder of a HW startup working in the LED space. One of our core patents is based on the concept of 'Polychromatic LED Light.' Our low-cost high-efficiency intelligent LED controls are designed to reproduce the full natural spectrum of lighting - more like natural sunlight than ever before possible.

Incandescents do generate high quality light but they too fall short at reproducing natural sunlight. Unfortunately because Incandescents were dominant for so long the industry has established a color rendering index (CRI) based on a black-body radiator which considers incandescent to be perfect even though it actually falls far short.

Fluorescents and Compact fluorescents produce horrible light as a result of the phosphor coating used to create white light. LEDs can be much better, though admittedly not all are.

All in all LED lighting is the future for a whole host of reasons. I can't wait to replace fluorescents and CFL which, as a result of their mercury content, are one of the most environmentally toxic 'green technologies' ever developed.

Just my, clearly biased, $0.02 :)

"Fluorescents and Compact fluorescents produce horrible light as a result of the phosphor coating used to create white light." That's a bit of an overgeneralisation -- there's a significant difference between the cheapo tubes and, say, an OTT tube (just one, albeit excellent, example of a full-spectrum fluorescent).

The easiest, cheapest way to get a decent idea of the spectrum is to use a CD or DVD (we've all got at least one coaster at home that used to be a disk). The data side makes a great diffraction spectrometer. A common industrial-grade tube has great gaping holes in the spectrum; an OTT is indistinguishable from indirect skylight (the 6500K "north light" of the studio artist's dream). It's a bit disconcerting at first, probably because we're very much used to incandescent light indoors ("daylight" photographic incandescents might hit 4200K when they're brand new, and they're WAY blue compared to standard bulbs at around 2500-2800K) but it can hardly be described as "horrible".

LEDs aren't quite there yet -- at least none of the ones I've actually seen are. On the other hand, I fondly remember a time when LEDs could not be seen at all outdoors in daylight and drank power at a rate that would have left a plasma TV in an envious rage -- one had to duck into the shade and press eighteen or so buttons simultaneously in order to tell time on a thousand-dollar digital watch. The idea of using an LED (other than a laser) to illuminate anything other than itself was laughable around 1980; the spectrum problem and diffusion are trivial compared to the problems that have already been solved. It won't be long.

Thank you very much for the CD/DVD idea! I see five clear differently-colored copies of my local compact florescent tube in my DVD's rainbow... can you confirm that I am interpreting that correctly as five spikes and virtually nothing in between those spikes?

My local incandescent lights are just a rainbow smear.

Oh, awesome, I can do it to my LCD screen too and clearly see three differently-colored reflections!

...

Forgive my geekout, but that's cool and I've never heard it before.

Why, yes. Yes I can confirm that. And I can tell you that noticing it about 25 years back, when I was doing photography professionally, saved me a metric crapload of money on special meters and so on -- but only after I had button-holed every single person I'd ever met to show them what I'd seen whether they cared or not. I truly understand the geek-out part.

Reply on news.ycombinator.com