Apollo Discussions > The Hoax Theory
Stereo parallax
JayUtah:
--- Quote from: MrSpock on May 04, 2012, 01:58:46 PM ---First off - I am absolutely not a hoax believer...
--- End quote ---
That was apparent in your first post. I'm sorry that it seems you're being asked to account for another's claims. Unfortunately many first-time posters arrive here "just asking questions" as a way to put critics off guard.
--- Quote ---Since I am not a photography expert or good at discussions I just thought if I throw the question in this forum I might get some answers that I can bounce back at him on the swedish forum.
--- End quote ---
Sure, I'm glad my answer helped. In general it's cumbersome to discuss here something that's happening in other forums, but if you find our answers useful then I'm willing to keep helping.
Referring again to http://www.aulis.com/stereoparallax.htm I find:
Step 3 of the proposed process mentions applying transformations in image space, such as perspective distortions, independent x- and y-axis scaling, and rotations. First, some of these would not be projection-preserving, and thus are invalid in rectification. Second, there is no mention made of how the parameters for these transformations are derived. Hence they amount to manual processing and therefore cannot be scientifically reproducible.
The proposed antiprojection, La = Lb b/a, is linear. Most lenses do not implement a linear projection model, and the Zeiss Biogon explicitly does not. Hence the mathematical framework is simplistic and incorrect.
Fig. 7 purports to show a parallax difference between two Apollo photos that include a distant background. The author believes that because a geometric change is apparent in the blink-comparator, this should be attributed to parallax. In fact the method fails.
* No values are given for any rotations, distortions, or other transformations applied to the photograph(s). The results are therefore irreproducible and scientifically invalid.
* A simple contrast expansion of the "difference" image shows misalignment in the ridge lines consistent with a rotation between raster images roughly coincident with the original line of sight. The author has misapplied his broken method and thus interprets the difference in rotation (and possibly subsequent distortive attempts to correct it) as parallax.
Figs. 10 and 11 are similar. The author applies uncontrolled, arbitrary image-space manipulations that are not projection-preserving, then proceeds to attribute resulting misalignment of the raster to parallax. And again, no method is shown for deterministically deriving the distortion parameters; it is purely subjective and therefore irreproducible.
The author then imagines that the effects he introduces through non projective-preserving manipulations are explicable in affine space by a sort of concave screen. This is pure fantasy: a much simpler explanation exists, that of the ineptitude of the author's image-space manipulation and his fundamental misunderstanding of the actual projective geometry at work here. He has proven absolutely nothing other than his ability to produce in one instance a distortion map that corrects for the distortion he previously applied in another instance. There is absolutely nothing here that is valid or proven to be a method for determining the authenticity of photographs.
Echnaton:
--- Quote from: MrSpock on May 04, 2012, 01:58:46 PM ---First off - I am absolutely not a hoax believer
--- End quote ---
I see that now. People here sometimes get a bit knee jerk to a short initial post, and that is reflected in my previous post. Sorry to have just skimmed and replied.
ka9q:
--- Quote from: JayUtah on May 04, 2012, 10:16:46 AM ---He skipped the part where he studied whether any distortions in the image might be caused by the non-linear effects of the Zeiss Biogon lens, a feature for which it is justly famous.
--- End quote ---
This was my first thought when looking at the pictures. I immediately noticed that the reseau marks had shifted quite a bit between each pair of pictures, meaning that the camera was pointed in different directions and that any geometric distortion in the lens would change the shape of even the distant scenery. That's one of the reasons the reseau marks are there. They're usually cited as accounting for any stretching of the film, but they would also help locate each feature within the lens geometry. You'd have to know what that geometry is to correct those distortions, but I presume that's known, and the marks are a lot more precise than the edges of the frame.
I didn't know until you just said so that the Biogon was "justly famous" for its non-linear effects.
ka9q:
--- Quote from: JayUtah on May 04, 2012, 10:16:46 AM ---Pseudoscience.
--- End quote ---
It certainly is pseudoscience, but I have to say that it was much better-looking pseudoscience than what usually passes for "evidence" that Apollo was hoaxed.
I didn't fully understand each of his steps as I didn't think he was worth that much effort. But I got the impression that, at one point, he distorts the image in a totally arbitrary fashion with many degrees of freedom and then complains that the background "parallax" disappears, thus "proving" that the background was projected on a screen. Wait -- wasn't it his original complaint that there shouldn't be any parallax on the distant scenery? Or we we supposed to forget that?
AstroBrant:
--- Quote from: JayUtah on May 04, 2012, 03:10:42 PM ---
--- Quote from: MrSpock on May 04, 2012, 01:58:46 PM ---First off - I am absolutely not a hoax believer...
--- End quote ---
That was apparent in your first post. I'm sorry that it seems you're being asked to account for another's claims. Unfortunately many first-time posters arrive here "just asking questions" as a way to put critics off guard.
--- Quote ---Since I am not a photography expert or good at discussions I just thought if I throw the question in this forum I might get some answers that I can bounce back at him on the swedish forum.
--- End quote ---
Sure, I'm glad my answer helped. In general it's cumbersome to discuss here something that's happening in other forums, but if you find our answers useful then I'm willing to keep helping.
Referring again to http://www.aulis.com/stereoparallax.htm I find:
Step 3 of the proposed process mentions applying transformations in image space, such as perspective distortions, independent x- and y-axis scaling, and rotations. First, some of these would not be projection-preserving, and thus are invalid in rectification. Second, there is no mention made of how the parameters for these transformations are derived. Hence they amount to manual processing and therefore cannot be scientifically reproducible.
The proposed antiprojection, La = Lb b/a, is linear. Most lenses do not implement a linear projection model, and the Zeiss Biogon explicitly does not. Hence the mathematical framework is simplistic and incorrect.
Fig. 7 purports to show a parallax difference between two Apollo photos that include a distant background. The author believes that because a geometric change is apparent in the blink-comparator, this should be attributed to parallax. In fact the method fails.
* No values are given for any rotations, distortions, or other transformations applied to the photograph(s). The results are therefore irreproducible and scientifically invalid.
* A simple contrast expansion of the "difference" image shows misalignment in the ridge lines consistent with a rotation between raster images roughly coincident with the original line of sight. The author has misapplied his broken method and thus interprets the difference in rotation (and possibly subsequent distortive attempts to correct it) as parallax.
Figs. 10 and 11 are similar. The author applies uncontrolled, arbitrary image-space manipulations that are not projection-preserving, then proceeds to attribute resulting misalignment of the raster to parallax. And again, no method is shown for deterministically deriving the distortion parameters; it is purely subjective and therefore irreproducible.
The author then imagines that the effects he introduces through non projective-preserving manipulations are explicable in affine space by a sort of concave screen. This is pure fantasy: a much simpler explanation exists, that of the ineptitude of the author's image-space manipulation and his fundamental misunderstanding of the actual projective geometry at work here. He has proven absolutely nothing other than his ability to produce in one instance a distortion map that corrects for the distortion he previously applied in another instance. There is absolutely nothing here that is valid or proven to be a method for determining the authenticity of photographs.
--- End quote ---
I was going to start a thread on this, but i saw that there was already a thread on it.
If and when I get off my butt and start making videos again, I would like to do one on Oleynik's analysis. Some of my critics and friends have suggested that I pay too much attention to relatively weak and insignificant hoax believers. So I decided to take on Oleynik. (Colin Rourke, too.)
I've read your comments and have already made some of the observations you have made here. The real challenge is that on YouTube I have to keep my video at a level which at least some hoax believers, (and Apollo defenders), can understand. Indeed, I have to be able to understand it myself.
Before getting into details and soliciting all sorts of advice from you, let me at least ask if you would be willing to do that. Of course, your help will be duly noted in my video. I'd like to get other people's ideas as well, so do you think I should post a new thread on this?
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