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View Full Version : Where are the 2 shadows on Tatooine?



JediTricks
09-10-2006, 02:26 PM
Riddle me this, mister digital-effects-tampering master Lucas, if you're so willing to go to the ends of the universe to make your movies better and more realistic for the audience to be engaged by, why is it that your precious and oft-visited Tatooine that has 2 suns hasn't had second shadows added to each character and item for daytime shots? ;)

Seriously though, twin suns might mean 2 shadows for each thing, right? When you have 2 spotlights on someone on stage from different angles they get 2 shadows after all. This would add an additional "alien" feeling to the world.

Kidhuman
09-10-2006, 02:55 PM
Jesus JT, now we have to buy all new versions again.&

stillakid
09-10-2006, 04:26 PM
Riddle me this, mister digital-effects-tampering master Lucas, if you're so willing to go to the ends of the universe to make your movies better and more realistic for the audience to be engaged by, why is it that your precious and oft-visited Tatooine that has 2 suns hasn't had second shadows added to each character and item for daytime shots? ;)

Seriously though, twin suns might mean 2 shadows for each thing, right? When you have 2 spotlights on someone on stage from different angles they get 2 shadows after all. This would add an additional "alien" feeling to the world.

Interesting question. I can't say for sure without some testing using some large sources (like 20Ks), but offhand, I'd have to say that you probably wouldn't see a double-shadow in the way that you describe because the sources (the twin suns) are A) really close together and B) really far away. Because they are so close together at that distance and are being diffused a bit through the atmosphere, they still act as one large source instead of two.

For instance, sometimes I have to hit an on-camera talent with two 800w HMI Jokers outside just to have a half a chance at combating the daylight lit background. I do other things to help, but for the purpose of the question, the light source is what is relevant. Anyway, if I place the sources right next to each other and I hit the talent with the two distinct sources from 6 feet away with no diffusion, I'll see two hard shadows. BUT, if I drop some kind of diffusion material in front of them, the "source" is more like a large soft light panel instead of two light "beams" traveling through space.

Tatooine doesn't appear to have a lot of cloud cover or atmospheric diffusion that would contribute to this, but it could be enough due to the proximity of both suns to one another. I mean, you might get a slight double-shadow, but it wouldn't be as prominent as if, say, one sun was high overhead while the other was closer to the horizon.

Slicker
09-10-2006, 06:10 PM
I was thinking the same thing stilla. The suns are so close yet so far away that the light most likely "combines" on it's way to the planet and forms just a single shadow.

basschick
09-10-2006, 06:18 PM
during most of the day, sunlight is pretty saturated, but as the sun(s) go down, seems to me you might well expect to see two shadows.

but PLEASE don't get lucas started on this! you don't wanna get him redoing them AGAIN :eek:

El Chuxter
09-10-2006, 06:35 PM
Because it was causing the guys at ILM a headache to figure out proper placement and intensity of the shadows, and after they worked for 72 hours straight and only got one shot done right, George decided to never mind the dual shadows.

2-1B
09-10-2006, 07:20 PM
I was thinking the same thing slicker. The suns are so close yet so far away that the light most likely "combines" on it's way to the planet and forms just a single shadow.

Rocketboy
09-10-2006, 08:54 PM
The lightsaber shadows bug me more.

stillakid
09-10-2006, 10:11 PM
I was thinking the same thing slicker. The suns are so close yet so far away that the light most likely "combines" on it's way to the planet and forms just a single shadow.

What happens when two shadows combine?

Kidhuman
09-10-2006, 10:15 PM
It causes the planet to explode

stillakid
09-10-2006, 11:41 PM
It causes the planet to explode

Are there two shockwaves or one?

basschick
09-11-2006, 02:01 AM
works for me :D


Because it was causing the guys at ILM a headache to figure out proper placement and intensity of the shadows, and after they worked for 72 hours straight and only got one shot done right, George decided to never mind the dual shadows.

Kidhuman
09-11-2006, 07:36 AM
Are there two shockwaves or one?

Its actually multiples just like the rings of Saturn&

JimJamBonds
09-11-2006, 09:54 AM
but PLEASE don't get lucas started on this! you don't wanna get him redoing them AGAIN :eek:

Its going to happen anyway regaurdless of a thread that JT starts or not. :D

JediTricks
09-11-2006, 04:33 PM
You know Lucas just read my thread and is sleeping a little worse tonight. :p

I don't think it'd be that hard for ILM to go back and add them, they added a ton of shadows for ESB and ROTJ:
http://www.starwars.com/episode-v/release/video/f20060901/index.html
http://www.starwars.com/episode-vi/release/video/f20060908/index.html

A sundial uses directional light from the sun, it's an ancient and proven technology, I don't buy that if you had a second sun several degrees over in the horizon that you wouldn't get SOME noticable amount of secondary shadow on that sundial. The Tatooine suns aren't shown right next to each other in each shot, some shots show them further apart.


I found this interesting post which contradicts the claim that the suns are so close together they'd cast just 1 shadow...

in response to the comment that stated that the suns are close enough to cast one shadow, this it geometrically incorrect. The Shadow that the sun would created is not just a function of how close the suns are to each other or how distant they are, but rather a function of both these factors. if the suns were so far away that the cast light at virtually the same angle, then when we see the suns in the bakground of the shot with anakin on the speeder, we would only see one sun. similarly, if the suns are close enough together that we should not see two shadows, when we look at the suns they should be so close together that we see only one sun. in short, the angle of the difference in the positions of the suns would be angle of the difference of the shadows. It appears to be about a 10 - 15 degree angle (about one hour if you were looking at it in terms of the time of day) when we see the two suns, so we should see a 10 -15 degree angle in the shadows.

stillakid
09-12-2006, 03:23 AM
It appears to be about a 10 - 15 degree angle (about one hour if you were looking at it in terms of the time of day) when we see the two suns, so we should see a 10 -15 degree angle in the shadows. [/FONT]
[/INDENT]

Perhaps, but an angle of that size won't create an appreciable second shadow. I guess we'd have to put up some lights and measure the angles to be sure, but my feeling is that what you'd see would look more like one wider shadow of the object than two distinct shadows as you'd see if the angle was much wider.

JimJamBonds
09-12-2006, 09:41 AM
Perhaps, but an angle of that size won't create an appreciable second shadow. I guess we'd have to put up some lights and measure the angles to be sure, but my feeling is that what you'd see would look more like one wider shadow of the object than two distinct shadows as you'd see if the angle was much wider.

If only somebody here worked in tv/movies that maybe we could find this out.... DANGIT! :D

stillakid
09-12-2006, 10:38 AM
If only somebody here worked in tv/movies that maybe we could find this out.... DANGIT! :D

Roger that! Work has slowed down in the past month... :(

LusiferSam
09-12-2006, 11:17 AM
If only somebody here worked in tv/movies that maybe we could find this out.... DANGIT! :D

If you have track lighting in your house you can see it work for your self. An interesting side point is the shadows would change as the stars orbit each other and the planet orbits them. So what we see in SW, ROTJ, TMP, AOTC, and at the end of ROTS would all be different. By the way JT thanks for finding that post explaining the angels, it saves me the trouble of typing my own explanation.

stillakid
09-12-2006, 11:48 AM
By the way JT thanks for finding that post explaining the angels,

I was wondering if they had anything to do with this. :D

darthvyn
09-12-2006, 01:12 PM
If you have track lighting in your house you can see it work for your self.

as long as the bulbs in your track lighting are the size of STARS!


A sundial uses directional light from the sun, it's an ancient and proven technology, I don't buy that if you had a second sun several degrees over in the horizon that you wouldn't get SOME noticable amount of secondary shadow on that sundial. The Tatooine suns aren't shown right next to each other in each shot, some shots show them further apart.


I found this interesting post which contradicts the claim that the suns are so close together they'd cast just 1 shadow...

in response to the comment that stated that the suns are close enough to cast one shadow, this it geometrically incorrect. The Shadow that the sun would created is not just a function of how close the suns are to each other or how distant they are, but rather a function of both these factors. if the suns were so far away that the cast light at virtually the same angle, then when we see the suns in the bakground of the shot with anakin on the speeder, we would only see one sun. similarly, if the suns are close enough together that we should not see two shadows, when we look at the suns they should be so close together that we see only one sun. in short, the angle of the difference in the positions of the suns would be angle of the difference of the shadows. It appears to be about a 10 - 15 degree angle (about one hour if you were looking at it in terms of the time of day) when we see the two suns, so we should see a 10 -15 degree angle in the shadows.


i'm not buying it... the sun our earth revolves around is SO immense that the solar rays that are cast upon our planet are nearly parallel... at most the difference between our shadows and those of a planet in a binary system should be a larger, more diffuse shadow than we have. that is not to say that there aren't two shadows, but not two DISTINCT ones - there should be a darker portion in between the two, where the rays from the stars are completely blocked by the object generating the shadow, and then a diffused corona on either side of that dark area, where the shadow is being washed out by the rays of each star opposing the other's shadow. in the case of a shadow of a man, you may see two washed-out bumps indicating the position of the head, but that would be the most variance.

bobafrett
09-12-2006, 02:59 PM
Perhaps one was a "False Sun", no? Or maybe for kicks, Tarkin went and blew up one of the Suns with the Death Star, so we only see the twin suns when Luke looks and reflects. I don't recall seeing them again, except for maybe in Jedi around Jabba's palace.

JediTricks
09-12-2006, 05:30 PM
Perhaps, but an angle of that size won't create an appreciable second shadow. I guess we'd have to put up some lights and measure the angles to be sure, but my feeling is that what you'd see would look more like one wider shadow of the object than two distinct shadows as you'd see if the angle was much wider.It'd depend on the distance and intensity, but I think none the less it'd create a second (and in this case, lighter) shadow. I tried something out, I got a large flashlight and a smaller flashlight (I know, not the most technically accurate, but I had all of a minute to test this) and what I got was 2 shadows and the areas they converged was dark while the areas they did not cover were lighter and of differing shapes, and because the light was from 2 different angles (even when close together), the converged main light's shadow was lessened and the convergance area's shape was truncated.


You're right L.Sam, as times of day and even seasons change the twin shadows will change with them.


as long as the bulbs in your track lighting are the size of STARS!It's not a question of the size of the light, only the size, angle, and intensity of the light in relation to the object. The sun is bigger than the Earth, does that mean the thing in the star we see in the sky every day is only about the size of a large beach ball? Of course not.


i'm not buying it... the sun our earth revolves around is SO immense that the solar rays that are cast upon our planet are nearly parallel... at most the difference between our shadows and those of a planet in a binary system should be a larger, more diffuse shadow than we have.The point is that if we can see the difference between the 2 suns on Tatooine, then they are far enough apart to cast 2 distinct shadows, if they were so close together that they didn't then we wouldn't be able to see both suns, they'd just look like 1 sun to us. Since they are clearly 2 separate light sources, they are far enough apart to point rays form 2 distinct locations and thus should be casting 2 distinct intersecting shadows.


that is not to say that there aren't two shadows, but not two DISTINCT ones - there should be a darker portion in between the two, where the rays from the stars are completely blocked by the object generating the shadow, and then a diffused corona on either side of that dark area, where the shadow is being washed out by the rays of each star opposing the other's shadow. in the case of a shadow of a man, you may see two washed-out bumps indicating the position of the head, but that would be the most variance.At that point the wash-out of the shadows should take off a significant portion of the main figure's converged shaodw, perhaps a quarter depending on the positions of the suns, so we'd have LESS shadow at that point than we do now except for the faint wash-outs, again a different shadow system from what we're seeing, plus at dusk and dawn the distinct shadows that are washed out at other times should show far more clearly such as the Binary Sunset scenes in ANH and ROTS.

stillakid
09-12-2006, 05:52 PM
This isn't a relevant point with this discussion since we're presumably talking about Tatooine when both suns are visible, but I got to wondering about the stars orbiting one another and what that would do to the planet.

When we actually see the twin suns in ANH, the planet is getting probably the worst that binary suns can hand out, being that both are shooting out heat somewhat equally. But if the suns were in orbit around each other and the "season" came when those on the planet's surface only saw one sun because the other was behind the first, then it stands to reason that the temperature difference would be appreciable.

darthvyn
09-14-2006, 11:43 AM
I tried something out, I got a large flashlight and a smaller flashlight (I know, not the most technically accurate, but I had all of a minute to test this) and what I got was 2 shadows and the areas they converged was dark while the areas they did not cover were lighter and of differing shapes, and because the light was from 2 different angles (even when close together), the converged main light's shadow was lessened and the convergance area's shape was truncated.

that sounds like what i described above... except that those lightsources were a lot closer to the object... with light from stars on a planet, i think you would get a lot more diffusion of the rays, and therefore a larger, more diffuse shadow, with the darker portion in the middle.



You're right L.Sam, as times of day and even seasons change the twin shadows will change with them.

assuming tatooine has the same degree of polar shift as earth. it could be straight up-n-down, and therefore have the same seasons dependent on lattitude all year round.

there is a chance that they never see the suns move in the sky - if the suns revolve around each other at the exact same rate that tatooine revolves around them, they will always look the same, static in the sky at the same position relative to each other. the only thing that would change their position in relation to tatooine is the rotation of the planet. this isn't out of the quesiton - our moon revolves around earth at the same rate it rotates, therefore we only ever see one side of it.


It's not a question of the size of the light, only the size, angle, and intensity of the light in relation to the object. The sun is bigger than the Earth, does that mean the thing in the star we see in the sky every day is only about the size of a large beach ball? Of course not.

it was mainly a joke about the track lighting, but experiments with flashlights or track lighting can't compare to the distance traveled and substances traveled through to get light from our sun to earth.


The point is that if we can see the difference between the 2 suns on Tatooine, then they are far enough apart to cast 2 distinct shadows, if they were so close together that they didn't then we wouldn't be able to see both suns, they'd just look like 1 sun to us. Since they are clearly 2 separate light sources, they are far enough apart to point rays form 2 distinct locations and thus should be casting 2 distinct intersecting shadows.

i understand that part, but i'm saying the distance between the suns and the planet is the main factor here... the rays from one sun would wash out the rays from the other, creating two separate parts of the shadow: the light outer part, and the rich creamy dark center. i just don't buy the part about the two distinct shadows, like cookie-cutter duplicates of each other. the farther they are apart, the less shadow we'll see, because the dark creamy center will be smaller. the diffuse corona of the shadow will be larger in comparison.


At that point the wash-out of the shadows should take off a significant portion of the main figure's converged shaodw, perhaps a quarter depending on the positions of the suns, so we'd have LESS shadow at that point than we do now except for the faint wash-outs,

that's what i said, right? it's a larger shadow because of the two sources of light, but most of it is diffused by the other sun... hence a larger, more diffuse shadow with the rich creamy center. the area without any shadow has two sets of rays beating down upon it. next to that we have the shadow corona that is only getting one set of rays - a visible change. in between we have an area that is only getting rays reflected off of objects around it, and another visible shift. the entire shadow will be larger, but less of it will be as dark in relation to a shadow on earth, with our one sun.


again a different shadow system from what we're seeing, plus at dusk and dawn the distinct shadows that are washed out at other times should show far more clearly such as the Binary Sunset scenes in ANH and ROTS.

yes, that's for certain. that's not the way it looks in the movies, but i'm just opposed to the idea that we have two perfect shadows - that would ignore the fact that there are two lightsources trying their damndest to drown out those shadows...

2-1B
09-14-2006, 06:42 PM
didn't I just read in the Pluto thread that we have educated physicists on these here forums ? let's get them on the case...

JediTricks
09-14-2006, 10:40 PM
Did someone mention that shadows can get fatter? I realized right after I posted last time that that's not possible, natural shadows can only get thinner.



that sounds like what i described above... except that those lightsources were a lot closer to the object... with light from stars on a planet, i think you would get a lot more diffusion of the rays, and therefore a larger, more diffuse shadow, with the darker portion in the middle.Perhaps, but look at a shadow on a bright day, it's not especially diffused by itself, if we have 2 very powerful light sources from 2 different angles I don't see how that means they're going to wipe each other out.


there is a chance that they never see the suns move in the sky - if the suns revolve around each other at the exact same rate that tatooine revolves around them, they will always look the same, static in the sky at the same position relative to each other. the only thing that would change their position in relation to tatooine is the rotation of the planet. this isn't out of the quesiton - our moon revolves around earth at the same rate it rotates, therefore we only ever see one side of it.But that's not the case, we see the suns closer and further from each other throughout the saga.


it was mainly a joke about the track lighting, but experiments with flashlights or track lighting can't compare to the distance traveled and substances traveled through to get light from our sun to earth.But it does matter, if it couldn't compare then scalable lighting wouldn't be possible, movies couldn't fake outdoor lighting in a soundstage. For our discussion, the shadows are only about the light's relation to the object, the intensity at the sun and distance travelled is totally irrelevant.


i understand that part, but i'm saying the distance between the suns and the planet is the main factor here... the rays from one sun would wash out the rays from the other, creating two separate parts of the shadow: the light outer part, and the rich creamy dark center. i just don't buy the part about the two distinct shadows, like cookie-cutter duplicates of each other. the farther they are apart, the less shadow we'll see, because the dark creamy center will be smaller. the diffuse corona of the shadow will be larger in comparison.Yes, the 2 shadows will be lighter than the center where they converge, but that doesn't mean they'll be impossible to see. Plus, even if your theory is right, every shadow on Tatooine is already wrong as it should be SMALLER than what we see and a chopped up shape.


that's what i said, right? it's a larger shadow because of the two sources of light, but most of it is diffused by the other sun... hence a larger, more diffuse shadow with the rich creamy center. the area without any shadow has two sets of rays beating down upon it. next to that we have the shadow corona that is only getting one set of rays - a visible change. in between we have an area that is only getting rays reflected off of objects around it, and another visible shift. the entire shadow will be larger, but less of it will be as dark in relation to a shadow on earth, with our one sun.No, shadows cannot get larger, they can get longer and shorter but only thinner not wider. And I'm not sold on the "most" part either, suggesting a significant amount more, like 90/10 or something.


yes, that's for certain. that's not the way it looks in the movies, but i'm just opposed to the idea that we have two perfect shadows - that would ignore the fact that there are two lightsources trying their damndest to drown out those shadows...Right, ok, not just 2 separate shadows. Still, there would be 2 distinct shadow shapes outside the converged corona even though they are lighter.

El Chuxter
09-14-2006, 11:43 PM
Did someone mention that shadows can get fatter? I realized right after I posted last time that that's not possible, natural shadows can only get thinner.

That's what Barbie and the media want you to think, you nasty Daffy-hating Doombot. I'm onto you. :mad: