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Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 10:32 am
by TheSkyIsTheLimit
OOps, just saw, its a SUNRISE :-)!

Would also have been a beautiyful sunset :-).

Henry

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 11:09 am
by Alnilam
I'm not convinced by the last schema because the distance between the two glass layers is too large compared with the distance between the window and the focus point of the camera (the CCD chip) !

Before reading this post, I was just comparing the distance of the sun images in the APOD picture and other pictures posted, and assumed to be window reflections. In the APOD picture and other pictures posted later, the distance is decreasing between the multiple images of sun, roughly in a 1/2 or 2/3 rate. In the other pictures, the distance is quite equal or slightly increasing.

In fact, with a focus point near infinity (all the sun images are quite neat), so with rays roughly parallel, the reflection in a two glass layers window produces equidistant images (see my schema below). It's not the patern in the APOD picture.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 11:11 am
by Belbear
I concur to the window reflection theory, because:

-The wide-angle picture clearly shows reflections from some nearby objects in the bottom left corner, so at least this one picture has been taken through a window pane at an oblique angle. I can only assume the zoomed-in pictures were as well.

-We can assume it's a double-glazed window, because that's the standard for the last two decades. These windows give multiple reflections that are offset at odd angles because of imperfect alignment of the two window panes.

-It explains why the author has seen the triple sunset with the naked eye. These reflections are always there but usually one does not notice them because of lack of contrast. The rising sun provides the necessary contrast, in those few minutes it's not yet too bright to look at.

-All ghost images are identical to the primary sun image. If atmospherical effects at long distance would cause reflections, the combination of sun, water surface and cloud layers would look different for each ghost image. The primary image is of course overexposed, and details are hidden by optical blooming. But these details show clearly in the much fainter ghost images.

-The strongly magnified pictures show a blurring of the reflections. This too is perfectly normal for window reflections. After all, window panes are NOT manufactured to optical mirror standards!

To conclude, I wish to congratulate Noemi for -deliberately or not- deceiving the APOD webmasters :mrgreen: and making it to the site with this picture, I would regret it if various copycats would try to do the same with this easy-to-reproduce effect.

Chris

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 11:15 am
by blastoff
Hello Folks. Sorry, but you window paners are all missing something so obvious. If light from the sun is coming in at that angle and bouncing back and fourth inside a double paned window of some sort, the "ghost" suns would appear to the RIGHT of the actual sun. think about it. try a simple experiment using two cd case covers and your desk lamp.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 11:26 am
by Beyond
the triple image of the sun is almost the exact same thing that you get with what is called 'heat mirror' windows. these windows have a thin sheet of metal coated plastic between the two panes of glass to reflect heat. if you hold a light bulb in front of the window, you will see three light bulbs. two from the two panes of glass and one for the metalic coated plastic. for those who are familiar with the bible, the triple image represents the 'father',the'son' and the'holy spirit', who are everpresent with this planet. the faintest one, that the picture taker could not see with her naked eye, represents the holy spirit. the middle image represents represents the son, who has not yet fully come into hi own and the brightest image represents the father of all. so there you have it! who says the bible and science do not go together?

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 11:34 am
by TheAdvis0r
I do like the answer that the triple sunrise could be due to the photograph being taken through the balcony window/sliding glass door. However, the clouds that are covering the two shadows to the left don't repeat at the same frequency (and seem not to show in front of the "main" sunrise). I would think it has to do with varying air densities at varying distances, as a poster has stated before. Either way, it is a neat image.

Another consideration is the lens on the camera itself, especially if there is a filter on the lens. The light could be intense enough to cause the image to repeat, but from my experience, the color of the light would be shifted and doesn't look natural (ie--when I took a picture of the moon at night, I had a "ghosted" moon that was a light green with no detail at all).

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 11:47 am
by Wayne
It's certainly a reflection train from a double glazed window. If you get the angles right, you can reflect six or more images of the Sun or Moon using such windows and they're perfectly visible to the naked eye.

What you end up with are multiple images, each spaced slightly closer to the last. This is clearly seen on the APOD image as well as the cloud bank in front of the Sun being also present on both other reflections: Obviously whatever is causing the phenomenon is between the observer and the cloud bank. This, then, would be a window.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 11:55 am
by davino
If it would be an atmospheric reflection, then I would expect at least some distortion (getting elliptic, or some height-dependent curvature). But the reflection looks perfectly round, especially in http://apod.nasa.gov/image/0908/IMG_9804.JPG

Also it seems to me (in IMG_9804.JPG) that the clouds in front of the first reflection, especially in the upper half, do not quite match the actual clouds on the left side of the reflection. The clouds in front of the original are invisible due to the blinding light.

So picture IMG_9804.JPG and IMG_9805.JPG make me think that we are looking at a window pane reflection.

But the last photo (http://apod.nasa.gov/image/0908/IMG_9810.JPG) is different. It is a bit tilted compared to the others. I find this picture harder to reconcile with the window pane hypothesis; we would have to explain why the reflection (if there is one) moved closer to the sun. The greater zoom level cannot do that. But the distance between the first and second image was also different from the original and the first image, and someone in an earlier comment attributed that to the windows not being perfectly flat, but a little wobbly. Then the "move" of the image could be explained if the photographer moved the camera (maybe she stood up or sat down or leaned against something to get a steadier hold). She should maybe have noticed that the image moved as she moved, but peering straight into the actual sun that is maybe less obvious than on the much less bright photo.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 12:13 pm
by JohnL
I am assuming that the picture is valid, because if the reflections had been created by the camera, none of the suns would have been BEHIND the clouds. However, if you will notice, the two on the left are behind clouds--and different clouds at that. Thus, all three must have been visible at the same time, and I believe the photographer's statement that he could see these reflections with his naked eye.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 12:37 pm
by mesaxi
I believe that this phenomenon was truely visible to the unaided eye. If you look at the secondary suns you can see that there are clouds passing in front of them in a non-repetative pattern. I don't think that would happen if it were merely a camera effect. I'm also willing to bet that if you were to measure the curvature of each sun they would not match up as they would if it were only a camera trick.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 12:39 pm
by jeyka
Another testimony:
about 10-15 years ago, I had a similar experience in France from a train (without a camera in hand, sorry...), close to Sunset.
It took me quite some time to understand this was *not* a double reflection. This became obvious once the first Sun disappeared behind a hill... the second was still there, quite visible.
NB that in my case, the second Sun was above the real one.

I can't say about the one which was shot by our observer, but I am eager to see a physical explanation else than a window multiple reflection...

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 12:46 pm
by kamoses
scjurgen wrote:I opt pretty much for a glass reflection (occam's razor teaches).

The distance of the 2 (or 3) after images is decreasing, much an effect of the angle of the window towards the scene.
In this pic I have put direct sun image as red, camera as black plane, and the ghost reflections inside the glass in orange.
Image

Also: the more far away the camera from the window, the less distant the reflections. the featherd borders should be an effect of the refraction on the glass surface.

The slight tilting from the horizon is simply because of the much higher than horizon position, but can also be induced by a non vertical window.

The previous mentioned clues (glass reflections in the wide angle shot) are consistent with my 2 Cents... :wink:

Jurgen
Isn't this backwards? Shouldn't the first reflection line be at the second window pane going off to the right, instead of at the first going left? It would seem to me that this whole window theory is problematic for one reason: The reflections should be to the right side of the Sun given the windows orientation. I'm not an optics expert, but I held up two mirrors at in the same orientation and the object viewed was projected to the right. Unless the window is somehow oriented in the other direction which seems unlikely.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 12:50 pm
by geckzilla
The reflections are behind the clouds because the original sun is behind the clouds. I wouldn't call it an obvious flaw in the window pane idea at all. It's impossible to see the form of the clouds which are in front of the original sun because it's so bright to the camera that the original shapes get blown out. But after they get reflected, the shades and forms become much more apparent. But I do agree that it does look strange. Reminds me of an APOD a while back in which Jupiter is shown alongside the moon and I commented that it's tricking my eyes because it's behind the cloud, yet it shines brightly. http://antwrp.gsfc.nasa.gov/apod/ap090714.html

Optics can be very tricky.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 12:52 pm
by Elias Chasiotis
At first the image looked fake to me, but then i remembered that i have seen sketches of multiple moons in the books of the master of atmospheric optics, Professor Marcel Minnaert (1893 - 1970). So, in his book "Light and color in the outdoors" (Springer- Verlag, 1993), page 80, the author writes: "beside and above the sun appeared no fewer than seven images of the sun, clear and undistorted. And this time they were photographed, clearly and unambiguously. The sun was about 2 °above the horizon at sea and the phenomenon lasted about three minutes. The images were bluish, while the real sun was bright orange". He tries to explain the phenomenon writing about "abnormal refraction of light" and finds very strange that the images were as sharp and of the same size of the sun.
As he notes: "Nature continually proves to be richer in possibilities than we imagine".
I personally have never seen a similar effect in my life. In the photo, cirrus clouds are present on the horizon, that can cause parhelia. Also, the typical form of inferior mirage that causes the "Etruscan vase" effect is seen, but this still doesn't explain the multiple suns.
Anyway, my final opinion is that the phenomenon is real and the photo original.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 12:58 pm
by eriks
missing camera information
The EXIF info for IMG_9810 says basically:
Canon PowerShot S5 IS
DateTime - 2009:07:10 04:31:30
ShutterSpeedValue - 1/403 seconds
ApertureValue - F 3.51

IMG_9802 was shot at:
DateTime - 2009:07:10 04:30:22
ShutterSpeedValue - 1/60 seconds
ApertureValue - F 2.71

This is the camera:
http://www.dpreview.com/news/0705/07050703canons5is.asp

Best regards, Erik Sundheim

Full EXIF output for 9810:
Make - Canon
Model - Canon PowerShot S5 IS
Orientation - Top left
XResolution - 180
YResolution - 180
ResolutionUnit - Inch
DateTime - 2009:07:10 04:31:30
YCbCrPositioning - Centered
ExifOffset - 196
ExposureTime - 1/400 seconds
FNumber - 3.50
ISOSpeedRatings - 80
ExifVersion - 0220
DateTimeOriginal - 2009:07:10 04:31:30
DateTimeDigitized - 2009:07:10 04:31:30
ComponentsConfiguration - YCbCr
CompressedBitsPerPixel - 2 (bits/pixel)
ShutterSpeedValue - 1/403 seconds
ApertureValue - F 3.51
ExposureBiasValue - 0.00
MaxApertureValue - F 3.51
MeteringMode - Multi-segment
Flash - Flash not fired, compulsory flash mode
FocalLength - 72.00 mm
UserComment -
FlashPixVersion - 0100
ColorSpace - sRGB
ExifImageWidth - 3264
ExifImageHeight - 2448
InteroperabilityOffset - 3346
FocalPlaneXResolution - 14506.67
FocalPlaneYResolution - 14485.21
FocalPlaneResolutionUnit - Inch
SensingMethod - One-chip color area sensor
FileSource - DSC - Digital still camera
CustomRendered - Normal process
ExposureMode - Auto
White Balance - Auto
DigitalZoomRatio - 1.00 x
SceneCaptureType - Standard

Maker Note (Vendor): -
Macro mode - Normal
Self timer - Off
Quality - Normal
Flash mode - Not fired
Sequence mode - Single or Timer
Focus mode - Single
Image size - Large
Easy shooting mode - Full Auto
Digital zoom - None
Contrast - Normal
Saturation - Normal
Sharpness - Normal
ISO Value - Auto
Metering mode - Evaluative
Focus type - Auto
AF point selected -
Exposure mode - Easy shooting
Focal length - 600 - 7200 mm (100 mm)
Flash activity - Not fired
Flash details -
Focus mode 2 - Continuous
White Balance - Auto
Sequence number - 0
Flash bias - 0 EV
Subject Distance - 4029
Image Type - IMG:PowerShot S5 IS JPEG
Firmware Version - Firmware Version 1.01
Image Number - 1009810
Owner Name -
Sharpness (0D) - 65523

Thumbnail: -
Compression - 6 (JPG)
XResolution - 180
YResolution - 180
ResolutionUnit - Inch
JpegIFOffset - 5108
JpegIFByteCount - 2326

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 1:21 pm
by green1
My inclination is to believe that the primary reflection is from a reflective surface, the faintest is from either the glass lens or window pane (also why it wasn't visible to the naked eye.) Note that the 2 reflections are the same in outline but vary in saturation, and both are different than the primary image. Since both reflections are different than the primary image, they must have a source at some distance from the viewer. My guess would be that the first reflection is off a large ice floe in the arctic. If it was reflecting off the sea it would be in a vertical alignment (similar to a double rainbow) so it must be reflecting off of a tilted surface. The viewed reflection is seen with the cloud shadow in different configuration than the primary image. it might be possible to triangulate the reflections to arrive at a general locale of the reflective surface.
If you want to be technical, all three images are reflections. The primary image is the result of lensing of the atmosphere, and is visible while the sun is still below the horizon.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 1:39 pm
by geckzilla
I'm still convinced that it's window panes. The confusion with the clouds I think is happening because there are also some tangents with the clouds that make it appear as though the sun's reflections are happening behind them instead of at the window pane. This may have also tricked the photographer since the illusion is so convincing.

I want this APOD to be some freaky rare event but given that it is so obviously taken from within an apartment and the photographer has not explicitly stated that it was not photographed from behind a window, I'm just not going to come to any wild conclusions.

Here are some more examples. I have yet to find a single example of a photograph in which the photographer says the image was taken outside without a window. There are many variations in appearance. And yes, I do realize this form of argument doesn't prove anything other than that the sun can reflect in window panes. It doesn't discount weird, rare atmospheric conditions. So you don't need to tell me this.

The sun appearing behind objects. Notice the object appears to blend in with the atmosphere in the reflection, giving it the appearance that it's part of the atmosphere. This could be happening in the APOD photo, except with a much more deceiving effect.
http://www.flickr.com/photos/bored-now/2364366219/
Image

Here's another example of the sun being reflected and seeming to appear behind clouds. But the photographer's explanation makes it obvious that it's just a window reflection. The optics in this photo are a bit different but you get the point. It looks like the sun is behind the clouds, but you know it isn't in this case.
http://www.flickr.com/photos/jahmed/3313303172/
Image

No clouds.
http://www.flickr.com/photos/finprkl/3363401032/
Image


The sun appearing in front of clouds (not sure they are even clouds). Also happens to be during a solar eclipse.
http://www.flickr.com/photos/anonymonk/8864769/
Image


Here's a double paned window plus a mirror behind, double whammy.
http://www.flickr.com/photos/86098197@N00/558159664/
Image


Four suns. Again, says they are through a window.
http://www.flickr.com/photos/pinkpepperphoto/1056562/
Image


More sun reflections through a window...
http://www.flickr.com/photos/judygr/2130953391/
Image



No explanation, just another example.
http://www.flickr.com/photos/spyndle/2941616946/
Image


And it also happens with the moon. Indeed, reflections can take on drastically different appearances than their original, blown out source.
http://www.flickr.com/photos/cpchang/1510389815/
Image

Triple moon crescent.
http://www.flickr.com/photos/ashwin1/2025002387/
Image

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 1:46 pm
by mgardula
On the far left of photo 9802. The concrete wall. Is this discoloration of the concrete or reflection on a pane of glass? I'm leaning towards reflection. It has to be a window creating the effect.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 1:51 pm
by Jaxxon
:wink: The window theory seems pretty obvious to me...there are some other examples posted that clearly recreate the same effect.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 1:53 pm
by tapesonthefloor
This is definitely caused by glass reflection, and wishful thinking (as illustrated by jeyka above: "but I am eager to see a physical explanation else than a window multiple reflection") is the only reason there's still any debate.

More Moon-reflections:

http://flickr.com/gp/tapesonthefloor/c12ci7

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 1:59 pm
by TheSciencePundit
@Alnilam

Your argument assumes that the two window panes are perfectly parallel. Even small differences in the distances between the windows or thickness of the glass will cause uneven distribution (or an upward or downward trend) of the ghost suns.

I am now convinced that this was due to a window or sliding glass door. It is far and away the most parsimonious explanation.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 2:05 pm
by drss123
I would agree with the window hypothesis except that the sun appears behind the clouds and the cloud pattern is different than it appears in the primary image of the sun. The window examples and "behind the cloud" examples given so far don't seem to have that difference. So, I'm leaning towards reflections similar to those experienced in sonar when there are thermoclines causing reflections or other Snellian :-) effect.

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 2:07 pm
by geckzilla
drss123 wrote:... and the cloud pattern is different than it appears in the primary image of the sun. ...
Can you see the entire cloud pattern in front of the sun?

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 2:10 pm
by orin stepanek
Maybe Barry & Noemi could tell us if they were indeed looking through a window or not. It would really send a light on the subject. 8)

Orin

Re: Cause of Triple Sunrise (APOD 2009 August 4)

Posted: Tue Aug 04, 2009 2:11 pm
by rschmit
I am an avid astronomer and have been for over 35 years. I have seen many strange and wonderful things in the sky, but they are usually restricted to the night time. This one was not. I have seen a similar aberration of the Sun. It was on a VERY cold morning (-35 F) in Duluth Minnesota. It was late January, 1986, but I don’t remember the day. I was cutting through the cafeteria, head down, on my way to my 8:00 class, when I caught a reflection of the Sun on the display case in front of me. It was rising above Lake Superior through the window behind me. I was surprised to see two suns, one on top of the other. When I spun around to look, I was even more surprised: the image remained: low in the sky, just clear of the horizon, one sun on top, one beneath it. I couldn’t believe my eyes and was convinced that the window was producing this image. Ignoring the morning chill, I went across to the cafe’s terrace entrance and pushed the door open against its will. Sure enough, with nothing but our atmosphere between me and Sol, the image remained the same.

I stayed to watch as long as I could, but the cold and the clock told me to get a move on and get to class. I had hoped to watch how this image would resolve itself (Would the second combine with the first? Would it simply fade?) However, I noticed no change during the time that I observed. Sadly, this was back before people carried phones in their pockets that had cameras in them. Actually, this was even before people carried phones in their pockets. Yes, kids, there was once such a time...

I assumed the cause to be a refraction caused by the thermal layers above Lake Superior and the city of Duluth, below the campus, along the water’s edge. There are many strange phenomenon that occur when the mercury dips so low.

My mind’s eye can vividly remember the scene as I recount the story here. It reminds me to look. Always look! You never know what you’re going to see!