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Bbrhuft t1_ixtmeue wrote

Reply to comment by purpleoctopuppy in What is the the irradiance (W/m^2) range of human vision? by DeismAccountant

Researchers a few years ago discovered that humans can see single photons.

>Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds.

Tinsley, J.N., Molodtsov, M.I., Prevedel, R., Wartmann, D., Espigulé-Pons, J., Lauwers, M. and Vaziri, A., 2016. Direct detection of a single photon by humans. Nature communications, 7(1), pp.1-9.

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purpleoctopuppy t1_ixtmrws wrote

Oh cool! Last I read is that our eyes could detect a single photon, but our brain would filter it out, good to know there's been progress in this! Being a single-photon detector is a cool flex.

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[deleted] t1_ixvk435 wrote

[removed]

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Bbrhuft t1_ixvwxhc wrote

The energy carried by a single photon of 500 nm light is 4.0 × 10^−19 J.

The approximate conversion is 1 Lux = 0.0079 W/m^2 for sunlight that has a peak at 500 nm.

3.16 × 10^21 lux.

The brightness at noon at the equator is 111,000 lux, of which (albedo) for bright sand is 0.4. So sand in desert at the equator at noon, will be around 44,000 lux.

Which is a dynamic range of approximately 1.4 × 10^25 .

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DeismAccountant OP t1_ixvzbjf wrote

Wait is this maximum or minimum?

Thank you so much but I’m sorry I’m so confused. Unless one is minimum and the other maximum.

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