The How of When

October 31, 2008 1:09 PM

Are dawn and dusk interchangeable in visual media? How does one differentiate a photograph taken in the early morning from one in the late afternoon? Can it be done?

If I asked you to tell me whether a given photograph were taken at dawn or dusk, what would you look for? Alternatively: if I filmed a movie at sunset and then called the movie "A Sunrise Scene", would anybody be able to call me on it? What might to help them distinguish a true dawn from my poseur dusk? Or is the difference all psychological? (Please assume all hypothetical footage and/or photographs contain a startling lack of clocks, sunflowers or people whose captured behaviour gives obvious clues as to the time of day.)

posted by CheeseburgerBrown to media & arts (22 answers total)

If the location of the photo was known, any outdoor shadows could be analysed to determine both the time of day and the approximate date. See this NY Times article for an example.

But, if you are assuming no clues like flowers, shadows,, clocks, etc. are present, then what's the point of your question?
posted by TDIpod at 1:21 PM on October 31, 2008

Ah, good question! Without notable landmarks or other tell-tale features, I think they're quire similar. An source-less wikipedia statement notes that "[t]he sunset is often more brightly colored than the sunrise,with the shades of red and orange being more vibrant.... However, differences between sunrise and sunset may in some cases depend more on the particular geographical features of the location from which they are viewed."

General tips for sunrise/sunset photos are the same, so it seems a safe bet that as long as you avoid east/west coast shots, or any well-known monuments, you're fine with faking the time of day.
posted by filthy light thief at 1:25 PM on October 31, 2008

Sunrise Colors ...the "sunset colors" section is exactly the same, so i'll only link once.

That's really scientific, though. I think generally people associate more light tints (light pinks and light oranges) with sunrise as opposed to the deeper hues of orange and red with sunsets.

Location also comes into play. Some places (such as Key West, Florida) claim to have a "flash of green" at the moment the sun sets. Though this may be visible at both the sunrise and the sunset, the tradition is most commonly associated with the sunset.
posted by cmchap at 1:26 PM on October 31, 2008

dadgumit. these mefites are just too fast!
posted by cmchap at 1:27 PM on October 31, 2008

In the summer, there's more haze at dusk, due to the sun creating humidity and cars making pollution. Dusk has more insects flying about, and maybe more birds. In cold weather, like this morning, near dawn, any frost is still on the ground, grass, leaves, weeds, etc., looking absolutely stunning. Bodies of water collect fog that burns off as the day progresses.
posted by theora55 at 1:27 PM on October 31, 2008

if I filmed a movie at sunset and then called the movie "A Sunrise Scene", would anybody be able to call me on it?

Well, at sunrise one would expect the sun to progressively rise higher and higher above the horizon over time. Seeing the sun get closer to the horizon, and shadows become longer, one might conclude that it´s not sunrise.
posted by yohko at 1:27 PM on October 31, 2008 [2 favorites]

I have always found that sunset is more dramatic, with brighter colors and sunrise is more hazy and gradual in its changes. I'm sure it varies by location but it's been true for me all over the world. I think twice nowadays about getting up to see sunrise over a popular monument, usually the sunset is better.
posted by Bunglegirl at 1:45 PM on October 31, 2008 [1 favorite]

I definitely associate sunset with a more orangish light and sunrise with a more white or pinkish light. But that could just be me, romanticizing sunsets.

However, this web site suggests that the "magic hour" referred to by photographers and movie makers is about the same, photographically, right after sunrise and right before sunset.

I wouldn't worry about the sun moving, if you're just talking about one scene. Scenes typically only last a few minutes. You'll have logistical issues with filming and continuity, but that's always the case.
posted by iguanapolitico at 1:50 PM on October 31, 2008

yohko said, Well, at sunrise one would expect the sun to progressively rise higher and higher above the horizon over time. Seeing the sun get closer to the horizon, and shadows become longer, one might conclude that it´s not sunrise.

Ah ha! But thanks to my giga-computer-based digital non-linear editatronium machine, I can shoot the shots out of order and then rejigger the sequence in order to fudge the progression of the sun.

TDIpod asked, But, if you are assuming no clues like flowers, shadows,, clocks, etc. are present, then what's the point of your question?

Well, I'm imagining we can see shadows. They're long. The light has a golden cast to it. Anybody capable of banging two rocks together knows we're seeing either dawn or dusk -- the question is: what gives away which is which? Do you follow me now?

Theora55 makes a good point about humidity -- that's a possible cue, visible in the quality of the atmospherics.

By the bye, I'm not actually making a movie; that was hypothetical. I am, however, building a CGI sequence that involves a sunset/sunrise time flyover of mountains...while I was fiddling with all the whatchamacallits and dodads in my compositing software I got to thinking about dawn versus dusk, and whether my idea that I can tell the difference is just a mental trick or my picking up on subtle atmospheric cues.
posted by CheeseburgerBrown at 1:57 PM on October 31, 2008

I say it would be tough to tell without really examining it. We've probably seen it many times in movies and TV without knowing it. Based on my extremely in depth education on such matters (listening to a lot of DVD commentaries) this is done quite regularly.

In fact, just last night I was watching an episode of The Wire with commentary. A character is at the front door at what is supposed to be about 5 in the morning. You can see that the sky is just getting light behind him. But the commentary says they shot it just after sunset and had to hurry before the light went away.
posted by Fuzzy Skinner at 2:11 PM on October 31, 2008

We also have cultural notions of sunrise/sunset to keep in mind. Sunrises are generally wetter, crisper, and golden. Sunsets are dry, hazy, and purple or pink. If you showed me a bona-fide sunrise that was pink and purple with dramatic clouds, I would probably still associate it with sunset, due to conditioning and schema.
posted by iamkimiam at 2:51 PM on October 31, 2008

Ah ha! But thanks to my giga-computer-based digital non-linear editatronium machine, I can shoot the shots out of order and then rejigger the sequence in order to fudge the progression of the sun.

Only if the shots are very short. The sun doesn't take that long to rise or set.
posted by Solon and Thanks at 2:53 PM on October 31, 2008

I know that they're often interchanged in moviemaking, which seems to suggest that if there is a difference, viewers don't notice or care enough to mind.

So the history of filmmaking, if nothing else, suggests that your plan is sound.
posted by rokusan at 2:54 PM on October 31, 2008

Keep in mind that the sun is neither rising nor setting. So really what you're asking is, "Without familiar landmarks, could you tell if the earth were rotating in the opposite direction?"
posted by weapons-grade pandemonium at 5:02 PM on October 31, 2008

Hmm...interesting question. My first thought was that some plants might give an indication of direction, but you might be disqualifying that with your comment about sunflowers. My second thought was that if the exposure was long enough then motion blur in the image might give something away. Couldn't come up with anything specific, though. Only other thought is that other bright heavenly bodies planets/stars/moon might be visible and be a giveaway. I don't know my astronomy well enough to say for sure (e.g. what could possibly be visible in a dawn or dusk shot).
posted by madmethods at 5:02 PM on October 31, 2008

In the Northern Hemisphere, shadows are normally cast northward. So sunrise and sunset could be figured out based on whether the shadows lean left or right from straight north. A scene with strong cardinal direction clues, like East/West running streets, might look funny.

Probably nobody would notice. A lot of inconsistent stuff sneaks into movies all the time, and nobody but fan club types notices. It'll give you something to say on the "director's commentary" track on the DVD.
posted by ctmf at 5:59 PM on October 31, 2008

In many places, sunset is much dustier.
posted by Lesser Shrew at 8:11 PM on October 31, 2008

The only differences I can think of are atmospheric; after all, the motion of the sun is symmetric. What matters is that it's cold and maybe damp before a sunrise, whereas it's warm and maybe dusty before sunset. So fog is more likely at sunrise, as is layering of fog/cloud near the ground because you only tend to get a low altitude inversion layer in the morning. Sunsets will be redder due to the dust.

So you can probably fake a boring sunrise with sunset as long as it's not too intense, but you can only get a genuinely beuatiful foggy sunrise in the morning. And you can't make that look like a sunset.
posted by polyglot at 12:01 AM on November 1, 2008

Humidity-related differences are the only thing I came up with. It would depend on the climate and season, but sunrise might reveal frost and/or dew that would be absent at sunset.
posted by jon1270 at 2:35 AM on November 1, 2008

Solon and thanks said, Only if the shots are very short [can you shoot the shots out of order and then rejigger the sequence in order to fudge the progression of the sun]. The sun doesn't take that long to rise or set.

The average shot length in a drama is about 2.5 seconds. Can you discern the motion of the sun in 2.5 seconds? How about 10?

jon1270 said, Humidity-related differences are the only thing I came up with. It would depend on the climate and season, but sunrise might reveal frost and/or dew that would be absent at sunset.

Yes, that's all I can come up with, too. Seems to be the current consensus around here.

Thanks for all of your thoughtful answers, everyone!
posted by CheeseburgerBrown at 5:09 AM on November 1, 2008

At the risk of stating something obvious, I would also add that if there are geographical landmarks indicating direction such as east or west it could be a dead giveaway. For example, if you're filming a scene from the Jersey side of the Hudson River looking at Manhattan, and the sky is glowing behind the island, you know it must be sunrise, since you're looking east and the sun rises in the east. Alternatively, if you're filming a scene from Brooklyn looking at Manhattan, and there's a glow behind the island, you know it must be sunset, since you're looking west and the sun sets in the west.
posted by saladpants at 9:06 AM on November 1, 2008

I don't know.. my colour perception is good and I can tell there's a difference. I look for shadows and stuff to confirm my suspicions but it's something about the qualities to the colours that tips me off.

And yeah - what Polyglot said - because where I am Sunrise is not interchangeable with Sunset.. at all! Hmm, I might have pics that illustrate this perfectly. If I find them - I'll share.
posted by mu~ha~ha~ha~har at 12:50 PM on November 1, 2008