Talk:Moonlight

Cant read books by moonlight? What! Of course you can. Full moon, countryside with no artificial urban light sources, its really not a problem.
 * Did you actually do it? &mdash; Monedula 16:12, 28 January 2006 (UTC)

I'm waiting for a clear night, and to be outside of the city. But i shall try.

Actually on a clear night far from cities, full moon with much snow on the ground I was able to both read and recognize colours. Not that it is very often to have such conditions, but than again - you only need one example to disprove such thing. --matusz 13:31, 19 July 2006 (UTC)

I live in sandstone canyon country in Northern New Mexico and love to ride the canyons at night. Visually one of the more interesting uses of moonlight is when a bright moonlight is reflected off one canyon onto the opposite canyon walls. It glows in a rather verbally indescribable manner. How one might capture that visually must be one of the problems that drive painters crazy here in New Mexico. Even a subtle problem for photograhy. Also the Chaco Canyon (100 miles west of here)    buildings are quite interesting for moonlight afficionados as, while the central plazas are layed out according to sunlight shadows other outlying buildings are laid out apparently by use of moon shadows, i.e. they are astronomical markers to the moon's meanderings. These were built 800 - 900 years ago and are supposedly the only known place where moonlight was used for building layouts. Again a testament to the brightness of moonlight in this country and yes, we have read in the moonlight here. Mike Logghe 16:42, 20 April 2006 (UTC)

Where does the 0.2lx number come from ? In the referenced article, 0.7lx is quoted from an article in german (which I can't read). Mauvaisours 12:28, 1 February 2007 (UTC)

500k times fainter?
If full-moon moonlight was 500,000 times fainter than sunlight, it seems to me that the moon would be completely imperceptible. I can clearly make out objects in a full moon without any artificial light, and I live mid-latitude and low altitude.Crd721 (talk) 06:26, 20 February 2008 (UTC)
 * Check Eye. It quotes 1,000,000 to 1 for brightest/darkest visibility ratio.  Theoretical range is 10 trillion to 1. Djdaedalus (talk) 13:43, 25 February 2008 (UTC)

Found how?
Looking at dung bettles seems an awfully roundabout way to find out that moonlight is polarised when scientists have access to polarising filters they can directly examine such things with. Did that sentence get mangled somehow? —Preceding unsigned comment added by 66.93.3.84 (talk) 04:20, 21 February 2008 (UTC)

Wait a minute...
isn't the picture in this article a picture of the Midnight Sun? It looks way too bright to be the Moon —Preceding unsigned comment added by 164.92.175.76 (talk) 16:03, 25 February 2008 (UTC) this rocks —Preceding unsigned comment added by 222.110.184.248 (talk) 08:46, 5 February 2009 (UTC)

Moonlight Colour Temperature
I have heard the colour of moon light as observed on earth as being 4000 Kelvin and 4150K Kelvin. Are there any research papers which confirm the colour temperature of moon light on earth? Certianly the colour temperature will change as the moon is at the horizon - but is there data on the nominal colour temperature of the moon? —Preceding unsigned comment added by 24.69.84.202 (talk) 19:16, 9 November 2009 (UTC)

This would be very POV, but I have a number of spectra of the moon at various phases and altitudes.. If you try to fit a black body curve to them, the best fit is indeed a little above 4000 Kelvin. GIven that the moon reflects more red than blue, and thus appears slightly "yellowish", that is perfectly consistent with it reflecting the sun's light at about 5500K and making it a little "cooler". — Preceding unsigned comment added by 2001:8003:E448:D401:B455:F4B7:4775:4322 (talk) 06:11, 9 March 2020 (UTC)

Problems with photos: I changed the image to a painting
Here's the thing about photographs taken in moonlight: they look exactly the same as photographs taken in sunlight, only darker. The silvery quality of moonlight is due to the eye's adaptation to low light levels - the rod cells take over from the cone cells, and we essentially switch into monochrome mode; also the response to blue light increases. Cameras can't capture this, so moonlight appears like daylight (or at low angles, like the light of a sunset). Also, that photo of the Rhine, though pretty, featured as much electric light as moonlight. For these reasons I have taken it out and put an artist's impression there instead. Card Zero (talk) 10:52, 24 October 2011 (UTC)

Brightness differences of the Sun and Moon not equal to their Albedos?
Can someone put an explanation or even a reference link to another site, explaining how the moon's albedo of 0.136 (I know there are more then one albedos but that's one type of them) does not make the full moon 13.6% as bright as the sun, but rather 400,000 times fainter?? There must be a big reason why, and it's not because of the moon's non-perfect smooth surface or anything like that.
 * Light scatters from the moon in all directions, not directly back like in a mirror. Since the moon is very small in the sky, that means that very little of the scattered light is directed towards Earth. Ckyba (talk) 08:03, 9 September 2014 (UTC)

Statement with correct data is incorrect due to mixed units.
"From Earth, the apparent magnitude of the full Moon is only about ​1⁄380,000 that of the Sun.[citation needed]"

Uhhh, no. If we accept that figure, then the apparent BRIGHTNESS of the full moon is that fraction, which equates to a MAGNITUDE DIFFERENCE of about 14. — Preceding unsigned comment added by 2001:8003:E448:D401:B455:F4B7:4775:4322 (talk) 06:07, 9 March 2020 (UTC)

"The color of moonlight, particularly around full Moon, appears bluish to the human eye compared to most artificial light sources due to the Purkinje effect.".
Whilst this is completely true, it merits more explanation. The Moon itself is slightly "yellow", so the light from the moon is therefore slightly "yellowish". However, if you look at "objects under moonlight" - that is, terrestrial objects seen by reflected moonlight, they are a lot fainter (just like things seen in daylight are a lot fainter than looking directly into the Sun), and hence due to the Purkinje effect will appear bluish.


 * (The above unsigned comment was left by 2001:8003:e448:d401:b455:f4b7:4775:4322 on 9 March 2020.)
 * This is a fair point, which is worth investigation, and finding sources for. Sunlight has a complicated graph showing different spectra for sunlight. The sky is blue (this, I'm told, can be said without a source) and hence indirect sunlight is blue, with peaks at around 400 to 450 nm (see light): might this also happen at night to moonlight? The graph of the direct sunlight spectrum, though, is low at 450nm and lower still toward violet, while flattish from about 475nm onward, so you get yellowish-white light (or strictly speaking, light lacking violet and low in blue wavelengths). Is the moon really slightly yellow, or is it grey, and reflecting yellow sunlight? Card Zero  (talk) 21:42, 24 May 2022 (UTC)

The part about blue or silver appearance

 * I have restored this part, written differently. It was removed by user:Firejuggler86 on the grounds that the light is obviously not blue (I think the edit summary said "no shit"). However, this is not obvious to everybody, and I believe "silvery moonlight" and sometimes even "blue moonlight" to be a common misconception. It's obvious - sort of - that the light has more or less the same spectrum as sunlight if you ponder that it's just reflected sunlight, but not everybody puts two and two together, it seems to me. The same user objected to being told that it appears silvery because this is unencyclopedic. Well, I could possibly find a source for that (which might mention the Purkinje effect yet again), but I think this is WP:BLUE obvious, and not an opinion or value judgement that we are imposing on the reader. "Silvery moonlight" is a common phrase. See for instance By the Light of the Silvery Moon (song).
 * In the same edit I changed a mention of "artificial light" to "brighter light", to underline the cause of the Purkinje effect and avoid the possible misconception that moonlight appears blue due to contrast with yellow artificial light. The artificial nature of other light is not the important thing that makes it different from moonlight. The faintness of moonlight is the important thing. In fact very faint white artificial light would also appear blue-tinged. Card Zero  (talk) 21:58, 24 May 2022 (UTC)

Purkinje effect cannot make light appear blue
The Purkinje effect explains why the eye is more sensitive to bluer light when it is very dim, because vision under low light conditions is via the rods, while bright light vision relies on the cones. Peak sensitivity for rods is blue shifted compared to for cones. However, rods enable grey scale vision, since they do not contribute to color vision. So moonlight, insofar as it is sensed by the rods, must be gray scale. If silvery refers to the gray scale, that is fine, but if silvery means bluish, that doesn't work because the rods don't sense color. — Preceding unsigned comment added by 69.53.43.240 (talk) 21:34, 23 June 2024 (UTC)

Inconsistency in moonlight illuminance
This article https://en.m.wikipedia.org/wiki/Daylight claim that moonlight can have up to 1lux, please dicuss with each other and provide consistance to people 183.182.111.149 (talk) 18:42, 20 February 2024 (UTC)