About 15000 photos tagged "sunset" taken within the last year. Compare to the previous photo, which graphs sunrises in the same way.
Their horizontal positions represent the day of the year the photo was taken. January is on the left, December is on the right. The vertical bars are the boundaries between months.
The vertical position represents the time of day the photo was taken, according to the EXIF data. The horizontal lines are hours, with the thick line in the middle representing 12 noon.
The deepest "dip" in the wave formed by the images is the Summer Solstice.
Since there was an increase in the amount of photos during the past year, I am dimming the photos proportional to the number of submissions for that day, to minimize the effect of increasing submissions and to keep the overall brightness uniform. This makes the seasonal change in sunset times more apparent.
Also note a slight echo around 5-7 am, which appears to be folks whose
camera clocks are 12 hours off.--
More stuff by jbum:
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striatic, wrenoud, samatriX.digitaL, lilic, and 47 other people added this photo to their favorites.

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samatriX.digitaL 100 months ago | reply
Such elegant displays of information. These things remind me Edward Tufte's work.
Are these graphs generated soley by code or is photo editing involved?
Really beautiful.
krazydad / jbum 100 months ago | reply
This graph was mentioned on Edward Tufte's website a few days ago, much to my delight.
This one was assembled solely by code. I did the "color of..." graph manually in Photoshop, working off the RGB data.
TheLawleys 100 months ago | reply
An interesting and impressive visualization, jbum. There's lots of info there. I'm curious to know what's going on with the outliers (other than the 12-hour echo). Mis-set clocks? Extreme latitudes? Non-literal uses of the word "sunset?" Probably some combination of these and more, but the stories behind the outliers always intrigue me. (k)
krazydad / jbum 100 months ago | reply
A few possibilities:
a) There's a line of photos at 8:00 AM. I assume this were assigned a 'default' time by some software (which software I wonder?) There are other photos that lie on other hour boundaries, which I assume are also either have hand-edited times or using default settings.
b) There are many many photos uploaded to Flickr that don't have
EXIF data. How are 'taken' times assigned to these? I don't know.
c) There are a few photos with sunset tags which are not of sunsets - e.g. "The Sunset Diner".
Neil 99 months ago | reply
I did not see this before! I love it. Very Tuftey.
Neil 99 months ago | reply
thoughts!
1) why do people start taking sunset photos around March? And why stop in the middle of the summer? (I'm wondering, why not autumn?)
2) what would a graph of all "outdoors" (plus strongly related tags) at *all* times look like? I want to see a swelling of blue around June shrinking to greyish in November, with fringes of sunset/sunrise color.
For maximum effect, perhaps creative techniques are needed to get only sky. Cropping to the top third or half of the image might work.
I'll might try that if you don't.
krazydad / jbum 99 months ago | reply
People don't stop taking photos in march. Flickr is only a year old, and the graph was made in February - so the March data was a year old, so fewer submissions to Flickr at that time.
fo.ol 99 months ago | reply
But in winter, for me at least, it's already dark by the time I get out of work.
_chance_ 99 months ago | reply
There's also not much of a sunset if the cloud cover is thick enough. Nor sunrise for that matter.
quasistoic 96 months ago | reply
Keep in mind that there are geographical locations called Sunset (Sunset Avenue, The Sunset District, etc) which might account for a few of the outliers.
Orrin 96 months ago | reply
Not to mention Sunset Boulevard, which I frequently use as a tag ...but I always write it sunsetblvd ...so as not to skew your graph!
Thanks for sharing these with us. I find them endlessly fascinating.
bovinity 94 months ago | reply
very hott. any chance of turning this visualisation into a poster too?
dmarks 92 months ago | reply
very cool!
Shield 84 months ago | reply
I'm so glad I found this- really amazing technique. I just blogged it here.
pitix 81 months ago | reply
Another likely cause for the outliers is longitudinal travel: when people travel across timezones, they're unlikely to reset their camera's clock, which would still be recording the time back home. Could the echo mean that people are more likely to travel to antipodeal longitudes than anywhere else?
krazydad / jbum 81 months ago | reply
Pitix: Good observation!
While this is a good explanation for some of the errors, I'm not sure it explains the 12-hour echo as well as the "am/pm" theory.
My guess is that people would be more likely to travel to closer destinations than the other side of the planet...
moronic_warwicks 78 months ago | reply
I'm assuming that this picture has the time scale reversed, so that lower down = later on?
I suppose that in (most of) the Southern hemisphere the seasons are reversed, so this image leads me to the conclusion that the vast predominance of submissions are from the Northern hemisphere.
All things considered that is not surprising ... but it's puzzling to me that we don't see anything other than this main band. This looks consistent with a range of curves going from the equator towards the north ... where are the opposite curves?
krazydad / jbum 78 months ago | reply
Here is a Southern Hemisphere sample:
moronic_warwicks 78 months ago | reply
sweet
SerialCoder 70 months ago | reply
This image has been added to the Flickr Museum for making explore's top 25. Kudos! You can check it out HERE...