|
| If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|||||||
| Register | FAQ | Members List | Calendar | Mark Forums Read |
![]() |
|
|
LinkBack | Thread Tools | Display Modes |
|
|||
|
Jay,
Great examples! If one looks at the very last image you can also see an example of how a surface can reflect back into the subject. Look at the shadow side of the battery nearest the camera. near the base you can see the black of the shadow reflected in the side of the battery. As you move upward the reflection of the black shadow ends and the light reflection of the table top begins. You can even see highlights on the ribbed edges at the top of the battery on the shadow side created by the reflected light from the table. Exactly what we see in the apollo photos. Your examples taken with the par lamp also show the other limitation of studio light...falloff. <font size=-1>[ This Message was edited by: infocusinc on 2002-06-02 21:18 ]</font> <font size=-1>[ This Message was edited by: infocusinc on 2002-06-02 21:21 ]</font> |
|
|||
|
"Look at the shadow side of the battery nearest the camera. near the base you can see the black of the shadow reflected in the side of the battery. As you move upward the reflection of the black shadow ends and the light reflection of the table top begins. Exactly what we see in the apollo photos.
" Must be airbrushed. [img]/phpBB/images/smiles/icon_lol.gif[/img] |
|
|||
|
Nice try Jay, but it is obvious that you faked these pictures. For one, in the first picture the "paint can" is clearly as large as the car behind it! I don't know what that has to do with anything, but if you went to the bother of making a car sized paint can, you must be hiding something.
|
|
||||
|
Great examples!
Thrown together from cardboard and dowels and a PAR yanked from my living room. I'll probably redo this demo with more controlled objects and terrain and an actual sun angle of 9°. You can even see highlights on the ribbed edges at the top of the battery on the shadow side created by the reflected light from the table. Sure, you and I agree that's what they are. But try to tell that to a hoax believer, who will just maintain it's scatter from the atmosphere. Your examples taken with the par lamp also show the other limitation of studio light...falloff. True. I have touched on this in various posts elsewhere, but I haven't gotten around to discussing it in detail. Of course a real studio lighting designer wouldn't use a PAR or any kind of flood to create the shadows on a set. But of course a focused spot (e.g., ellipsoidal) has other unpleasant properties. And there's still falloff. I have some proof photos of various umbra/penumbra effects, but so far no page in which to incorporate them. |
|
|||
|
I've been following the discussions on this board for quite some time, simply because it's rather fun to see what the HBs will come up with next, but I've never written anything here before.
However, after seing the excellent photos in this thread, demonstrating the shadow effect, I realized this bordered on my field of expertice. I've been working with computer animation and special effects for quite some time, and I realized this would be a perfect opportunity to use this knowledge. What I did was this: I downloaded the image of the two astronauts with different shadow length from Cosmic Dave's site. I then applied the same techniques used to integrate live action and CG data in motion pictures (in this case front projection and tracking), and created a 3D model of the shading situation in the picture. Actually, I created two shading situations. One for the scene lit by the sun, and one for the scene lit by a stage light. Here are the results: Original image Sun lit scene Stage light lit scene Of course, this is just a quick lighting test, and it's not perfect. Still, it clearly shows a couple of things: First, the shadow length is wrong in the scene using the stage light, but correct in the sun lit scene (if the shadow length of the second astronaut should be correct, the shadow of the first will be wrong, and the other way around, when using the stage light). Second, the light from the sun create sharp shadows (just like in the original image), while the stage light crate fuzzy shadows. Here is the LightWave scene for download, if anyone wants to examine the scene setup: Scene There are free scene viewers available on the net, and the scene file itself is readable by a human, so anyone should be able to verify that this is not a fake. The reason I include it here is that I would very much like Cosmic Dave or anyone from his camp to look at it and tell us which one they think look more like the real photo - the sun lit or the stage light lit scene - and in order to do so it is necessary that they can verify that the scene setup is indeed correct. |
|
|||
|
Nice job M_. The sharp vs. fuzzy shadow lines is something I've never considered, but your picture makes it very clear.
However, don't count on dave responding or correcting his website. (correcting correcting) <font size=-1>[ This Message was edited by: Tomblvd on 2002-06-03 12:40 ]</font> |
|
|||
|
Quote:
M, nice work. Question on your second image, the stage lit one. Am I noticing a slight blurring of the figures? If so I'm wondering what's causing that. |
|
|||
|
Welcome M. Nice job you did.
But I have a question. Did you take the shape of the terrain into account? In that photo I don't think they are standing on flat ground. I believe they are in a bit of a depression, where the shadow of the astronaut on the right is stretched out on a downslope, but the one on the left is on an upslope and thus foreshortened. That might have a bigger effect on the shadows than the type of lighting used. At least I think so. Jay or someone may be able to help us out here?
__________________
...And that, my liege, is how we know the Earth to be banana-shaped. --Sir Bedevere |
|
||||
|
Interesting pictures but you've slipped up. The pictures you posted using artificial lighting look the closest to the Apollo shots. They show the vast difference in shadow angles which are not apparent in your last picture posted using direct natural sunlight. If you had adjusted the lamp more to the bottom of the picture and had made the light lower, i think that you would have had very a similar picture to the Apollo one posted on this page.
The sunlight picture you posted shows that the shadow lengths of both objects are almost identical and nothing like the vast difference of lengths shown in the Apollo picture. But if you think I'm not right, perhaps you could post a picture taken of the batteries in natural sunlight and positioned in the same way that the Apollo picture posted here is arranged. In other words so that the shadows fall from SE to NW. |
|
|||
|
pvpylot, I'm not sure what you mean by blurring of the figures - they are identical in the sun lit and the stage light lit scene.
David Hall, yes, I took the shape of the terrain into account (see the linked scene file). However, I don't have access to the actual topographic data set, so I did what CG artists usually do - look at the scene and estimate the ground curvature, and create an approximation of it that fits the ligting situation. There are undoubtly errors in the recreated topographic data, but I belive it is still accurate enough to show the point I was trying to make. Actually, the middle point of the terrain should probably be slightly higher, but this was just a quick lighting test and nothing more, so I didn't bother to spend too much time on getting the curvature of the shadows right. Instead, I focused on the length of them. What I wanted to show was two things: First, the terrain topography will indeed create different length of the shadows when the sun is used to light the scene. Artificial light is not needed for this. I believe the included scene file is unrefutable proof of this, if Cosmic Dave would bother to actually look at it. And second, I wanted to show that the sun and only the sun can create the kind of shadows seen in the picture. <font size=-1>[ This Message was edited by: M_Welander on 2002-06-03 13:00 ]</font> |
|
|||
|
Quote:
|
|
|||
|
Quote:
As for PvtPylot's blurred vision, I see some blurring of the figures too. It looks to me like an artifact of the CGI process though, as it's visible on all of the figures.
__________________
...And that, my liege, is how we know the Earth to be banana-shaped. --Sir Bedevere |
|
|||
|
Yes, the blurring of the figures is there because they're really nothing more than texture mapped silluettes. There was no reason to include fully 3D astronauts just to show the length of the shadows. As you said, David Hall, the effect is identical in both CG images.
|
|
||||
|
The pictures you posted using artificial lighting look the closest to the Apollo shots.
No, they most certainly do not. The artificial lighting photo puts the longer shadow on the wrong astronaut in the arrangement where they are collinear. (http://www.clavius.org/shadlen.html Fig. 1) Compare with photo #2 above. The artificial lighting photo exhibits marked shadow divergence from only a 15° lateral separation, whereas no such divergence appears in http://www.clavius.org/shadlen.html Fig. 6. If you had adjusted the lamp more to the bottom of the picture and had made the light lower, i think that you would have had very a similar picture to the Apollo one posted on this page. If that is your belief then provide your own empirical evidence to substantiate it. Lowering the light will only increase the lengths of the shadows. It will not materially change their angles. The sunlight picture you posted shows that the shadow lengths of both objects are almost identical and nothing like the vast difference of lengths shown in the Apollo picture. Photo #11 above is meant to demonstrate http://www.clavius.org/shadlen.html Fig. 6, as opposed to David Percy's suggestion which is illustrated in photo #6 above. Photos #1-3 above are meant to demonstrate http://www.clavius.olrg/shadlen.html Fig. 1, the effect of terrain variation on shadow length, as opposed to David Percy's suggestion which is illustrated in photos #4 and #5 above. David Percy wishes to argue that both Fig. 1 and Fig. 6 on my site can be explained by the astronauts' position and motion relative to a nearby light source. I have shown conclusively that such a theory will not produce the effects seen in Figs. 1 and 6. David Percy wishes to argue that such shadows cannot be produced by natural light. I have shown conclusively that such shadows can indeed be produced if the terrain in question is sloped in a particular way. David Percy naturally argues that the terrain is flat there, and produces evidence which he believes demonstrates its planarity. I have taken Percy's evidence and shown conclusive that it demonstrates, on the contrary, the exact position and nature of the contour which would produce the shadows in Fig. 1. Further, I can cite evidence from the rest of the 16mm DAC footage, which David Percy chooses not to present, which clearly show Armstrong's shadow bending and changing in length as he carries the television tripod out to its distant location. This effect can only be caused by terrain variation. But if you think I'm not right, perhaps you could post a picture ... No, how about you post some evidence now? I've provided the empirical proof you asked for. I have provided the theory. I have provided example and counter example. You no longer have the luxury of saying this question has not been answered. It's clear you don't even understand what's going on here. First demonstrate that you understand this evidence. Then you may ask for more. |
|
||||
|
No, I will not be posting any simulations because it was you who bigheadedly tried to show everyone that you could prove me wrong with your pictures and claimed that you could recreate the Apollo shadows with natural light. Now your trying to back off and not support your claim, an act which you have accused me of doing over the past few days of debate. Its time to put your money where your mouth is.
Do you seriously think that the pictures which show the pegs on a piece of card reproduces the angle that the astronauts were standing at on the lunar surface? Wouldn't they have fallen flat on their faces? Perhaps you could reproduce picture 10 with the sun to the right of the frame? then that would show a comparison to the picture we are talking about. Your supposed evidence doesn't even start to reproduce the shadows in the Apollo picture at all, whether your trying to create them with artificial light or natural sunlight. |
|
||||
|
Oh, come on, Dave - Jay clearly stated that the board in the first series of photographs was angled that way to make the sun-surface angle comparable to the Apollo photos (which were taken near lunar dawn). I doubt that very many people on this board had the "wouldn't they fall on their faces" reaction that you did.
And, no, you can't accurately reproduce the pertinent Apollo photograph with the batteries standing on a table - a table is flat and the lunar surface is not. After reading all of these posts, I'm seriously beginning to think that you know perfectly well that the Apollo landings were real and you're just playing some kind of immature game . . .
__________________
SeanF "Ask to understand, but don't challenge unless you have the knowledge."--NEOWatcher The contents of this post are ©2009 by SeanF and may not be copied or retransmitted in any form without the express written consent of SeanF |
|
||||
|
No, I will not be posting any simulations
Then I reject your theory. ... it was you who bigheadedly tried to show everyone that you could prove me wrong with your pictures ... at your repeated request! You are really something. You chew me out because I don't have any empirical examples. I provide the examples, and you say, "No, I think if you had done it this way it would have proved my point instead," and then you refuse to provide substantiation? You have made a whole string of accusations and have admitted not wanting to spend the time or having the inclination to support them. Why should anybody take you seriously? Now your trying to back off and not support your claim No, I have supported my claim. And I have further given empirical evidence to disprove your claim. You have not provided one iota whatsoever of empirical evidence to back up what you say should and would be the case. My money is firmly where my mouth is. Do you seriously think that the pictures which show the pegs on a piece of card reproduces the angle that the astronauts were standing at on the lunar surface? No, I don't. But it shows that the contour of the terrain will affect the apparent length of shadows in exactly the same way that the lengths of the shadows appear to be affected in my Fig. 1. It is not quantitatively exact, but then again you never answered my question whether you would accept miniatures. Perhaps you could reproduce picture 10 with the sun to the right of the frame? Perhaps you could actually back up with some actual evidence what you believe to be true. Your supposed evidence doesn't even start to reproduce the shadows in the Apollo picture at all Yes, Dave, it does. Conclusively. It shows that the type of contour I have shown is present in the Apollo photo will have that qualitative effect on the shadows in the Apollo photo. whether your trying to create them with artificial light or natural sunlight. The point, quite bluntly stated, is that you can't reproduce the Apollo photo using artificial light. I have demonstrated this. If you believe that it can be reproduced with artificial light, then it is up to you to devise a demonstrate to prove it. (N.B. -- This paragraph originally said "natural" instead of "artificial". I meant "artificial". Sorry for the confusion.) You choose not to. Therefore I can quite justifiably say that you refuse to supply any evidence in favor of your argument. Are you happy with that? <font size=-1>[ This Message was edited by: JayUtah on 2002-06-04 14:38 ]</font> |
![]() |
| Thread Tools | |
| Display Modes | |
|
|