Home Spectroscopy

Since I primed the backdrop, every time I look at it with the layout lights on, it feels awfully blue. So, I decided to see if I could really understand what is going on with the lights.

This Saturday, we mostly had rain (go figure, it’s Vancouver!), and so, the kids and I set off on a science expedition. Our first step was to procure a crystal with which we could bend light. I was surprized to find that there is no box of light experiments on the toy store shelf next to the “build your own volcano” set and the “fun with magnets.” I mean, light is pretty interesting stuff, and it’s free and everywhere. Children should learn about light. Well, there’s a business opportunity there for someone.

After exhausting the toy stores and Dollarama, and after stopping for replenishment at Tim Hortons, we looked in at Swan Crystal because they had lots of crystal chandeliers in the window. They helpfully provided us with a couple of extra dangly bits for chandeliers, and we were off to the races.

The boy was all too happy to carve a triangular hole in the wine box with his jack knife. And then we started experimenting. Unfortunately, the chandelier crystals were too absorbent to scatter the light nicely. Fortunately, my wife reminded us about some crystal candle holders, and so, we pressed them into service. The next day, when the sun came out, the boy found a really nice piece of quartz, and so we tried that out too.

The results are shown below:

Daylight (glass)

Daylight (quartz)

Cool White 4500K LED

Warm White 3100K LED

All layout lights

Incandescent room light

One thing that stands out is just how very bright the sun is! It’s also interesting that I can barely discern any green in the spectrum (this was my experience as well as the camera’s). Most importantly, however, the spectrum is much broader than that which I am getting from either of the LEDs. There are reds further to the left and blues further to the right that are not there in the LED spectra.

I think that sums up the qualitative experience of LED light as well (and fluorescent light, although I didn’t measure it). Compared to sunlight, and even compared to incandescent light, LED light feels “thinner.” It doesn’t have the same rich warmness that sunlight has.

Now, mixing the “warm” and “cool” whites obviously helps a lot: the blues are almost absent in the warm white, and there is only a sliver of red in the cool white. But even with this mix, LEDs can’t hold a candle to daylight.

The bottom line? I’m still happy with my choice to go with LEDs: they are low power, quiet, cool and thin. I think, however, I should add another strip of the warm white to balance the cool whites, and this will hopefully jolly-up the whole feel of the layout.


2 thoughts on “Home Spectroscopy

  1. Now that I think about it, probably the reason why the greens are missing is because the hole in the box was too big. Well, it’s not like I could really measure he individual wavelength intensities anyway. Indeed, it’s a bit surprising you could discern anything from such a setup.

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