Topic: | Re:Re:Re:Re:Re:Re:Re:Holograms - a technical query | |
Posted by: | Chris Andrews | |
Date/Time: | 09/12/13 16:25:00 |
Based on what I know about optics, of which I did a term studying at university, and what I believe to be currently possible in holography; I would say that we are way off having such a sophisticated projecting system that can convincingly project on a moving platform on such a scale to fool thousands of witnesses. This applies for whether you believe it was a missile made to look like a plane through holography or whether it was a complete hologram without physical substance (indeed that scenario would raise more questions - how can the sound of jet engines be emitted from a hologram?) In terms of the apparent disappearing wings/horizontal stabilisers; video examples have been of poor quality and they present significant and obvious compression artefacts (pixellation/blocking). The thing with video compression codecs generally is that they work out the difference between two frames of a video and will only record the information representing that difference, i.e. it doesn't record 2 full frames of video, but rather the first full 'keyframe' and then the differences that you would need to apply to the keyframe to recreate the second frame. This is how video files can be made reasonable sizes - as only the transition information between frames are recorded, and when playing a video back the codec will reconstruct the video based on the original 'keyframe' and the subsequent differences that were recorded. Now you'll notice that the left-hand wing disappears pretty much when the wing overlaps the WTC. This is exactly what you would expect with poor video compression; as the wing is a similar colour/shade to the WTC the compression algorithm does not see this as a 'difference' and so when the video is played back it does not draw in the wing, but instead retains the feature from the previous frame. You'll see this also occurs when the wing goes in front of smoke of a similar colour. Video compression is a trade-off; the smaller you want to make the video filesize, or the less pixels you want to use, the more frugal the codec must be in recording differences. This video is certainly an example of this. |