<p>The answer by @comprehensible nicely states that whatever the effect might be, it is related to your camera. Of course the moon's light has a spectrum all the time, just like the sun, but we don't see it until we look through some dispersive material or object.</p>

<p>I thought I would just add a little back-up information as well.</p>

<p>I took your photo and rotated, cropped, and flipped it left-right on my laptop, then made 1D plots of the three color channels (R, G, B) normalized to local (R+G+B) by projecting down to the new x-axis. Note that this is <strong>very unscientifically done</strong>, but it's still interesting.</p>

<p>If the dispersion were diffraction, then moving away from the moon you'd expect to see the order B, G, R, B... since diffraction peaks are at larger angles for longer wavelengths. It would repeat if there were multiple orders. Of course this is messy geometry and the source (the moon) is very wide, so this is only guessing.</p>

<p>Surprisingly, this is the order that appears! So it's possible that there is some periodic pattern somewhere on the lens or in the camera. Since the characteristic size of one cycle is of the order of the diameter of the moon or about 0.01 radian, if there scratches or streaks on the lens the period owould be of the order of 100 wavelengths. There is an obvious periodicity in the camera's CCD (assuming it's not a film camera) but then the ray tracing would be more complicated (multiple reflections) and this simple analysis wouldn't work.</p>

<p>This is just speculation, and thin film interferece can also produce color effects also, and non-uniform thickness (like a soap bubble) can make color gradients as well. </p>

<p>Also note, our perception of color is a complex subject, and while our eye and brain together try to reconstruct a rich color behavior, the simple up and down wiggles of the intensity in the three color channels of your camera's sensor is all that is actually in the photo. </p>

<p>The color modulation is quite strong, so I am guessing that whatever is producing the 1 directional flair is also the thing that has the periodicity.</p>

<p>Why don't you try a similar experiment and point at strongly overexposed LEDs or maybe street lights (Sodium or Mercury vapor) and see if you get a clearer effect. This would be just for fun. This is just an artifact of your camera and has nothing to do with the moon. </p>

<p><a href="https://i.sstatic.net/MkNMT.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/MkNMT.png" alt="enter image description here"></a></p>

<p><a href="https://i.sstatic.net/2N8Nb.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/2N8Nb.png" alt="enter image description here"></a></p>

<p>Here's the Python script I used to plot the image after I rotated/cropped/flipped it on my laptop:</p>

<pre><code>import numpy as np
import matplotlib.pyplot as plt

fname = "Moon Spectrum.png"

img = plt.imread(fname)

img1D = img.sum(axis=0).T[:3]

img1Dnorm = img1D/img1D.sum(axis=0)

plt.figure()

plt.subplot(2,1,1)
plt.imshow(img)

plt.subplot(2,1,2)
for thing, color in zip(img1Dnorm, ['red', 'green', 'blue']):
    plt.plot(thing, color=color)

plt.xlim(0, img1Dnorm.shape[1])

for lab, x, y in [('B',  58, 0.35), ('G',  80, 0.39), ('R',  97, 0.31),
                  ('B', 126, 0.36), ('G', 141, 0.46), ('R', 166, 0.40) ]:        plt.text(x, y, lab, fontsize=14)

plt.show()
</code></pre>

CC BY-SA 3.0
2016-12-03T07:40:06.257Z
Very nice work!
pela
CC BY-SA 3.0
2016-12-03T10:16:20.740Z
@pela Ha, can't call it work! I had to reverse my hypothesis when I realized I'd used Matplotlib's default color sequence and mislabeled the colors!
uhoh
CC BY-SA 3.0
2016-12-03T11:28:52.073Z
Nice Python script. I checked briefly about lens flare coatings and found masses of pics of the sun with blue/green side bands, it's as if lens flare and ghosting which occurs with bright sources of light makes mostly bluish reflections. if you check the reflection of a window in a camera lens, you may see multiple different colored windows reflect from the lens.
bandybabboon
CC BY-SA 3.0
2016-12-03T06:32:49.393Z
2016-12-03T23:35:02.430Z
2016-12-03T23:35:02.430Z
uhoh
<p>The moon doesnt have really have 7 colors, you are having a slight prismatic effect from the lens. If it was an effect of the atmosphere you would have seen it. </p>

<p>The sun's spectrum peaks in greenish colors, and the moon peaks in yellow and red colors. That explains why the moon is more yellow than the sun, although they both can look red when they are rising and setting. </p>

<p>The colors on your photo are more blue, if you look into the lens of your camera near a window you will probably see a blue window and a white window, it is the lens flare coating and a lens artefact. The flare on the moon is also blueish green, same as your lens. </p>

<p>Here are photos of lens flare of the sun and there is a lot of information on avoiding lens flare and different types. This pic of the sun also has violet lens flare:
<a href="https://i.sstatic.net/TsZCl.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/TsZCl.jpg" alt="enter image description here"></a></p>

<p><a href="https://www.google.fr/search?q=flare+and+ghosting&amp;num=100&amp;espv=2&amp;source=lnms&amp;tbm=isch&amp;sa=X&amp;ved=0ahUKEwiBvJ-S89fQAhXBtxQKHTDKAggQ_AUICCgB&amp;biw=896&amp;bih=542" rel="nofollow noreferrer">https://www.google.fr/search?q=flare+and+ghosting&amp;num=100&amp;espv=2&amp;source=lnms&amp;tbm=isch&amp;sa=X&amp;ved=0ahUKEwiBvJ-S89fQAhXBtxQKHTDKAggQ_AUICCgB&amp;biw=896&amp;bih=542</a></p>

<p>here are the Sun and the Moon's spectra/colors if you have a good prism: </p>

<p>sun
<a href="https://i.sstatic.net/scHZs.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/scHZs.jpg" alt="enter image description here"></a></p>

<p>moon
<a href="https://i.sstatic.net/dA15P.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/dA15P.png" alt="enter image description here"></a></p>

CC BY-SA 3.0
2016-12-03T04:28:08.613Z
It doesn't make that much difference to understand the notion of a spectrum, which is clearly what the photographer is learning.  i don't mind getting bad points in my attempt to help out a question which i predicted would get downvoted here for it's spelling mistakes and general prase construction.
bandybabboon
CC BY-SA 3.0
2016-12-03T04:38:45.863Z
Is it worthwhile to make comments about H20 absorption troughs for a photo that has major aberrations. the side spectrum is mostly green.
bandybabboon
CC BY-SA 3.0
2016-12-03T23:32:03.153Z
Looks good - very helpful answer! But I don't think you can compare the two spectra directly. The units on the vertical axis of the Sun spectrum (black background) is labeled as `counts`, which means it hasn't been corrected for the efficiency of the instruments. The shape is a combination of the real spectrum, the sensitivity spectrum of the silicon sensor, and the instrument efficiency including the grating. The second one has units of radiance and has been corrected for all of those *plus* the fact that the shorter wavelengths have *more energy per photon* than longer wavelengths.
uhoh
CC BY-SA 3.0
2016-12-03T04:06:12.707Z
2016-12-03T11:34:19.657Z
2016-12-03T11:34:19.657Z
bandybabboon
<p>As others have mentioned, it is a prismatic effect due to your lens and/or the periodic nature of the way your camera's sensor absorbs light. Such effects are present in pretty much <em>all</em> photographs of large, strong light sources taken with cameras and lenses intended for artistic photography. When properly exposed the effects are generally controlled well enough to not be blatantly visible in the resulting photograph. When grossly overexposed, however, as is the case in this photo then the effects are more pronounced.</p>

<p>For a good example of how exposure differences affects lens flare and other effects caused by light reflecting off the surface of optical elements of a lens or sensor, please see <a href="https://photo.stackexchange.com/a/41724/15871">this answer</a> to this question at Photo.stackexchange: <a href="https://photo.stackexchange.com/questions/41722/can-you-photograph-the-milky-way-with-a-full-moon-out/41724#41724">Can you photograph the milky way with a full moon out?</a></p>

<p>For how to get best results when photographing the moon at night, please see <a href="https://photo.stackexchange.com/questions/459/how-do-i-set-the-proper-exposure-for-nighttime-moon-photos/34084#34084">How do I set proper exposure for night time Moon photos?</a></p>

CC BY-SA 3.0
2016-12-03T23:38:37.057Z
Those are really helpful links! Streaks and flares are common, but I still haven't found a single example of this spectral effect with repeating colors. I'm sure that I've seen them, but so far can't actually find a example anywhere to show that this isn't unique.
uhoh
CC BY-SA 3.0
2016-12-04T19:15:11.490Z
@uhoh What type of camera and lens did you use? Any filters on the front of the lens?
Michael C
CC BY-SA 3.0
2016-12-04T23:27:20.710Z
Oh I mean I am sure I've *seen flares with repeating colors in photographs somewhere*, but I don't remember where I've seen such photographs. In books of photography, or the internet...
uhoh
CC BY-SA 3.0
2016-12-03T12:02:51.613Z
2016-12-03T12:30:50.503Z
2017-04-13T12:44:06.413Z
Michael C
<p>I took a photo of SuperMoon 2016 and it was very shiny, the light around it showed seven colours. Was it my camera's effect or was it the moonlight's true colours. <a href="https://i.sstatic.net/4rhCI.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/4rhCI.jpg" alt="enter image description here"></a></p>

CC BY-SA 3.0
2016-12-03T03:52:59.007Z
@PearsonArtPhoto My comment was deleted during the migration. The Photography Stackexchange has an active Astrophotography tag as well. And since this is an optical effect of the camera lens or possibly a window (and not actually related to the Moon), it could arguably be asked in Physics Stackexchange also.
uhoh
CC BY-SA 3.0
2016-12-03T08:37:13.690Z
Not seven colours, but a continuous spectrum. There is no empirical basis for describing the rainbow as having exactly seven colours.
James K
<the-moon><photography>
Does supermoon's white light splits into seven colours
preeti
# Does supermoon's white light splits into seven colours

(Asked by: username_0 on 2016-12-03)

I took a photo of SuperMoon 2016 and it was very shiny, the light around it showed seven colours. Was it my camera's effect or was it the moonlight's true colours. [![enter image description here](https://i.sstatic.net/4rhCI.jpg)](https://i.sstatic.net/4rhCI.jpg)

**Tags:** the-moon, photography
> **Comments:**
> **username_1**: @PearsonArtPhoto My comment was deleted during the migration. The Photography Stackexchange has an active Astrophotography tag as well. And since this is an optical effect of the camera lens or possibly a window (and not actually related to the Moon), it could arguably be asked in Physics Stackexchange also.  
> **username_2**: Not seven colours, but a continuous spectrum. There is no empirical basis for describing the rainbow as having exactly seven colours.  

---

## 3 answers

### Answer by username_1 on 2016-12-03. Score: 6

The answer by @comprehensible nicely states that whatever the effect might be, it is related to your camera. Of course the moon's light has a spectrum all the time, just like the sun, but we don't see it until we look through some dispersive material or object.
I thought I would just add a little back-up information as well.
I took your photo and rotated, cropped, and flipped it left-right on my laptop, then made 1D plots of the three color channels (R, G, B) normalized to local (R+G+B) by projecting down to the new x-axis. Note that this is very unscientifically done, but it's still interesting.
If the dispersion were diffraction, then moving away from the moon you'd expect to see the order B, G, R, B... since diffraction peaks are at larger angles for longer wavelengths. It would repeat if there were multiple orders. Of course this is messy geometry and the source (the moon) is very wide, so this is only guessing.
Surprisingly, this is the order that appears! So it's possible that there is some periodic pattern somewhere on the lens or in the camera. Since the characteristic size of one cycle is of the order of the diameter of the moon or about 0.01 radian, if there scratches or streaks on the lens the period owould be of the order of 100 wavelengths. There is an obvious periodicity in the camera's CCD (assuming it's not a film camera) but then the ray tracing would be more complicated (multiple reflections) and this simple analysis wouldn't work.
This is just speculation, and thin film interferece can also produce color effects also, and non-uniform thickness (like a soap bubble) can make color gradients as well. 
Also note, our perception of color is a complex subject, and while our eye and brain together try to reconstruct a rich color behavior, the simple up and down wiggles of the intensity in the three color channels of your camera's sensor is all that is actually in the photo. 
The color modulation is quite strong, so I am guessing that whatever is producing the 1 directional flair is also the thing that has the periodicity.
Why don't you try a similar experiment and point at strongly overexposed LEDs or maybe street lights (Sodium or Mercury vapor) and see if you get a clearer effect. This would be just for fun. This is just an artifact of your camera and has nothing to do with the moon. 


Here's the Python script I used to plot the image after I rotated/cropped/flipped it on my laptop:
import numpy as np
import matplotlib.pyplot as plt

fname = "Moon Spectrum.png"

img = plt.imread(fname)

img1D = img.sum(axis=0).T[:3]

img1Dnorm = img1D/img1D.sum(axis=0)

plt.figure()

plt.subplot(2,1,1)
plt.imshow(img)

plt.subplot(2,1,2)
for thing, color in zip(img1Dnorm, ['red', 'green', 'blue']):
    plt.plot(thing, color=color)

plt.xlim(0, img1Dnorm.shape[1])

for lab, x, y in [('B',  58, 0.35), ('G',  80, 0.39), ('R',  97, 0.31),
                  ('B', 126, 0.36), ('G', 141, 0.46), ('R', 166, 0.40) ]:        plt.text(x, y, lab, fontsize=14)

plt.show()

> **Comments:**
> **username_3**: Very nice work!  
> **username_1**: @pela Ha, can't call it work! I had to reverse my hypothesis when I realized I'd used Matplotlib's default color sequence and mislabeled the colors!  
> **username_4**: Nice Python script. I checked briefly about lens flare coatings and found masses of pics of the sun with blue/green side bands, it's as if lens flare and ghosting which occurs with bright sources of light makes mostly bluish reflections. if you check the reflection of a window in a camera lens, you may see multiple different colored windows reflect from the lens.  

---

### Answer by username_4 on 2016-12-03. Score: 2

The moon doesnt have really have 7 colors, you are having a slight prismatic effect from the lens. If it was an effect of the atmosphere you would have seen it.

The sun's spectrum peaks in greenish colors, and the moon peaks in yellow and red colors. That explains why the moon is more yellow than the sun, although they both can look red when they are rising and setting.

The colors on your photo are more blue, if you look into the lens of your camera near a window you will probably see a blue window and a white window, it is the lens flare coating and a lens artefact. The flare on the moon is also blueish green, same as your lens.

Here are photos of lens flare of the sun and there is a lot of information on avoiding lens flare and different types. This pic of the sun also has violet lens flare:
[![enter image description here](https://i.sstatic.net/TsZCl.jpg)](https://i.sstatic.net/TsZCl.jpg)

[https://www.google.fr/search?q=flare+and+ghosting#=100&espv=2&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiBvJ-S89fQAhXBtxQKHTDKAggQ\_AUICCgB&biw=896&bih=542](https://www.google.fr/search?q=flare+and+ghosting&num=100&espv=2&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiBvJ-S89fQAhXBtxQKHTDKAggQ_AUICCgB&biw=896&bih=542)

here are the Sun and the Moon's spectra/colors if you have a good prism:

sun
[![enter image description here](https://i.sstatic.net/scHZs.jpg)](https://i.sstatic.net/scHZs.jpg)

moon
[![enter image description here](https://i.sstatic.net/dA15P.png)](https://i.sstatic.net/dA15P.png)

> **Comments:**
> **username_4**: It doesn't make that much difference to understand the notion of a spectrum, which is clearly what the photographer is learning.  i don't mind getting bad points in my attempt to help out a question which i predicted would get downvoted here for it's spelling mistakes and general prase construction.  
> **username_4**: Is it worthwhile to make comments about H20 absorption troughs for a photo that has major aberrations. the side spectrum is mostly green.  
> **username_1**: Looks good - very helpful answer! But I don't think you can compare the two spectra directly. The units on the vertical axis of the Sun spectrum (black background) is labeled as `counts`, which means it hasn't been corrected for the efficiency of the instruments. The shape is a combination of the real spectrum, the sensitivity spectrum of the silicon sensor, and the instrument efficiency including the grating. The second one has units of radiance and has been corrected for all of those *plus* the fact that the shorter wavelengths have *more energy per photon* than longer wavelengths.  

---

### Answer by username_5 on 2016-12-03. Score: 1

As others have mentioned, it is a prismatic effect due to your lens and/or the periodic nature of the way your camera's sensor absorbs light. Such effects are present in pretty much *all* photographs of large, strong light sources taken with cameras and lenses intended for artistic photography. When properly exposed the effects are generally controlled well enough to not be blatantly visible in the resulting photograph. When grossly overexposed, however, as is the case in this photo then the effects are more pronounced.

For a good example of how exposure differences affects lens flare and other effects caused by light reflecting off the surface of optical elements of a lens or sensor, please see [this answer](https://photo.stackexchange.com/a/41724/15871) to this question at Photo.stackexchange: [Can you photograph the milky way with a full moon out?](https://photo.stackexchange.com/questions/41722/can-you-photograph-the-milky-way-with-a-full-moon-out/41724#41724)

For how to get best results when photographing the moon at night, please see [How do I set proper exposure for night time Moon photos?](https://photo.stackexchange.com/questions/459/how-do-i-set-the-proper-exposure-for-nighttime-moon-photos/34084#34084)

> **Comments:**
> **username_1**: Those are really helpful links! Streaks and flares are common, but I still haven't found a single example of this spectral effect with repeating colors. I'm sure that I've seen them, but so far can't actually find a example anywhere to show that this isn't unique.  
> **username_5**: @uhoh What type of camera and lens did you use? Any filters on the front of the lens?  
> **username_1**: Oh I mean I am sure I've *seen flares with repeating colors in photographs somewhere*, but I don't remember where I've seen such photographs. In books of photography, or the internet...  

---

