I'm posting this to highlight the possibly unexpected effects of the strong
blue-light component in White phosphor type LEDs.

It's reported that paintings from around 1890 which use the "Chrome Yellow"
yellow pigment are at risk of rapid fading when LED lighting is used. I
surmise (possibly incorrectly) that this is caused by the strong blue
component in such lighting.


http://rt.com/art-and-culture/news/van-goghs-changing-color-901/

While not many of us are liable to have our Von Goghs faded by our LED
lighting, the blue component of white LED light can be significant and can
be damaging in some cases.
Light at the blue end of the spectrum is of high energy and able to cause
eye damage at apparently modest levels in worst case conditions.
If it's able to cause fading in a Van Gogh it might cause damage to eg
ink-jet images over time.

A few years ago I had a 150 mW white LED formally evaluated by its
manufacturer. This is a very low power level by most standards for power
white LEDs. To my surprise it  constituted a eye hazard at the blue end of
the spectrum when assessed to the relevant standard. While in this case the
chances of anyone staring into the beam from the minimum distance for long
enough was vanishingly small, in other situations and with LEDs in the 1
Watt + class, real hazards may exist.





                 Russell
--=20
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