Introducing f.luxometer!

  • If you've ever wondered what the light you see looks like (and how it affects your body), check out our new project:

  • Will there be a way to request or provide SPD for other spectrum. For example, it would be nice to have more streetlights. We (Mont-Megantic Dark Sky Reserve) have begin using PC-amber LED streetlights on our territory to reduce impact of blue light at night. Would be nice to direct more people to your website and tools.

  • Also, would be nice to have the actual lux value with the "X% as bright as daylight".

  • Yes, we will have a really neat way to add your own SPD.

    If you have some data you'd like to donate in the meantime, email me a CSV: - for now everything is available under our Creative Commons license. We can handle any resolution.

  • @remiboucher Yes that first number is a map of melanopic lux through a logistic function (which converts to the body's logarithmic units). It is not linear.

    For the linear numbers you can refer to "Photopic lux" or "Melanopic lux" to get the lux value we measured. In the case of the "lights" section, we have normalized most of them to 100lux, but everything else (including "streetlights") is based on actual irradiance as we measured it. When we measure luminance we show both cd/m2 and lux, since we've scaled luminance using our panel model (but this is mostly used for screens).

    Our streetlight measurements are a small sample from lights near us in LA. We measured vertical irradiance (looking up standing directly under a light) to avoid stray light from landscape and commercial lighting (so this is the brightest you'd typically encounter).

    RP-8 includes "luminance" measurements as roadway cd/m2 specifications too, but that is often to account for the dimmest spot on the roadway, not the brightest. So here we've mostly measured the brightest spot, and I believe diffused illuminance is the best measure of that.

  • @larna please pin this post to the top!

  • @lorna, can you push this to the top again please? I know it's on the main website, but if people go looking for it, then it's much easier to find--can you pin it to the top, or does it always go to the bottom of the page?

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