The human eye is less sensitive to red light and more sensitive to green light, when compared to white light, soooo shouldn’t there be an alteration of the ANSI standard for getting the correct range spec? Does a light meter account for how our eyes see colours? If not, then the range specs and what we see would be wrong.
Green would result in throwing further than spec and red would be less.
When filming white light with X camera settings, I have to reduce the exposure when I switch to red because the camera sees way more light than I can see, so I think there would be some error in how we measure throw with colours.
I think it’s an interesting topic worth bringing up.
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Isn’t ANSI range based on lumen numbers, and lumen is largely biased towards green light?
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The range is related to the luminous intensity (candela), illuminance (lux) and luminous flux (lumen). They all have in common that they incorporate the sensitivity of the human observer. 1000lm in green has the same brightness as 1000lm in red (but bit the same radiant flux, i.e. power of electromagnetic radiation).
Your camera sensor has a very different response and doesn’t measure the full spectrum with its Bayer filter. When transforming the pixel data into an image, each value goes through a pipeline with black and white point settings, gain and gamma curves and eventually white balance. This process changes the ratio between the color channels and transforms them into a color value in the chosen color space.
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