triphosphor fluorescent — three narrow phosphors plus the mercury lines, and the white it produces
Drawn at its defaults, in real light sources.
It reads 3 options and
no others: which, obs, marks.
Called by 4 essays
the blast radius of changing it
A lamp is not a blackbody
A fluorescent tube puts a third of its light into four mercury lines. A white LED is a blue spike with a hole beside it. Both are sold by a colour temperature, and a colour temperature says nothing about either.
What light isA lamp has a direction
A white LED is a blue die under a converter, and light leaving at an angle has travelled further through the converter than light leaving straight up. So the mixture is different in every direction, the beam is bluer in the middle than at its edge, and the number on the box is one direction's worth of a device that has no single colour.
What light isWhich lamp changes are free
The changes of light that existed before electricity commute with one another to a couple of parts in a thousand, so one set of axes handles all of them. The lights the lighting industry invented do not, and the worst pair in the census is seventy-six times further from commuting than the best.
What light isThe row a fourth dimension improves
Giving the test surfaces one more degree of freedom makes almost every change of light harder for an adapted observer — but not all of them, and which one it helps depends entirely on what the extra dimension looks like. A triphosphor tube is improved by one shape and hurt more than anything else in the census by another.