Author Topic: Stabilised Apollo 16 LRV Footage  (Read 9213 times)

Offline Inanimate Carbon Rod

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Stabilised Apollo 16 LRV Footage
« on: July 03, 2012, 03:08:13 PM »


Also, check out the comments from the hoaxers - the usual mix of ill informed comments about radiation and that special YouTube stupid we all know and love - in fact it's like peering into a raging furnace of stupid.
« Last Edit: July 03, 2012, 03:29:23 PM by Inanimate Carbon Rod »
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Offline Inanimate Carbon Rod

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Re: Stabilised Apollo 16 LRV Footage
« Reply #1 on: July 03, 2012, 03:18:00 PM »
On a related point, does any know what the duration of the longest continual take of any LRV is?
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Offline RAF

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Re: Stabilised Apollo 16 LRV Footage
« Reply #2 on: July 03, 2012, 07:22:25 PM »
I had not seen that, before...thanks for posting it.

Offline ka9q

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Re: Stabilised Apollo 16 LRV Footage
« Reply #3 on: July 04, 2012, 09:19:43 AM »
Video stabilization can be a godsend. I wish it had been around in the early 1960s when the Zapruder film was still new.

It works best for handheld footage. It isn't as effective on the later footage taken by the camera mounted on the moving LRV.

I notice there's some residual distortion due to the lens as the camera direction changes. I wonder how hard it would be for a stabilizer program to correct for that too. It would somehow have to be told the precise details of the lens, though.

Offline Glom

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Re: Stabilised Apollo 16 LRV Footage
« Reply #4 on: July 04, 2012, 02:28:51 PM »
That is so cool.

The distortion caused by the changing angle is quite noticeable.  Would that be described as astigmatism in the lens?  It's like the camera is drunk.

But I don't know I like the way the dust billows off those wheels.  I don't think that's the way dust should billow on Earth.

Offline cjameshuff

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Re: Stabilised Apollo 16 LRV Footage
« Reply #5 on: July 04, 2012, 02:51:40 PM »
The distortion caused by the changing angle is quite noticeable.  Would that be described as astigmatism in the lens?  It's like the camera is drunk.

Some distortion is inherent to the projection from a 3D scene to a plane, even in an ideal pinhole camera with no lens. It could be removed, and you could probably infer a decent model of the lens from the video, but apart from being more complex, it could introduce blurring/smearing and loss of resolution.

Offline Glom

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Re: Stabilised Apollo 16 LRV Footage
« Reply #6 on: July 05, 2012, 01:39:22 AM »
It's just so awesome.  It's the clearest video ever seen from the Lunar surface.  Really makes it so much more immersive.

It also makes clear like never before just how desolate the Moon is, particularly the bit with the camera on the LRV looking forward at their path; an endless sea of dust, dust and more dust.

Offline ka9q

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Re: Stabilised Apollo 16 LRV Footage
« Reply #7 on: July 05, 2012, 01:41:04 AM »
The distortion caused by the changing angle is quite noticeable.  Would that be described as astigmatism in the lens?
Astigmatism is something else. That's when a lens is not circularly symmetrical and it can't bring all parts of an object into focus even though they're all at the same distance from the lens. It's a common defect in the human eye. Glasses and contact lenses are ground with two separate focal length parameters, a "spherical" focal length to adjust for simple near and far-sightedness, and a "cylindrical" focal length to correct for astigmatism. The axis of the cylinder is specified with a rotation angle.

The effect here is a shift in position around the field of view, not a shift in focus. Because you are projecting a sphere onto a flat surface, you have the same problem that mapmakers do. If your field of view is very narrow, e.g., through a telephoto lens, your field of view is such a small section of the sphere that you can pretend that it's totally flat, just as a map of a town or small city can pretend the earth is flat. But as the map covers more of the globe, the non-flatness of the earth becomes harder to ignore. There are many map projections, some more common than others, but none is superior in all cases which is precisely why there are so many.

I don't know the kinds of projections that real lenses use, or if they are even standardized. I do know that wide angle lenses can have at least two very different projections, "normal" and "fisheye".

Offline cjameshuff

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Re: Stabilised Apollo 16 LRV Footage
« Reply #8 on: July 05, 2012, 09:11:25 AM »
I don't know the kinds of projections that real lenses use, or if they are even standardized. I do know that wide angle lenses can have at least two very different projections, "normal" and "fisheye".

Normal lenses approximate a pinhole camera. Straight lines remain straight lines after projection, etc. At wide angles, the image toward the sides becomes extremely distorted, and the geometry just doesn't work beyond 90 degrees from the direction of the camera. Fisheye lenses don't preserve straight lines, but spread the distortion around. There's several different projections with properties like preserving angles, areas, etc, and some lenses produce a circular image on the plane with no cropping.

Offline Peter B

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Re: Stabilised Apollo 16 LRV Footage
« Reply #9 on: July 05, 2012, 11:30:30 PM »
I had not seen that, before...thanks for posting it.

+1

It's amazing what detail you can see when the image is steady. Was anything done to improve the image quality as well, or is it solely...er...steadyising?

I was similarly impressed (and vaguely appalled) when I saw the same technique applied to the Zapruder film, which I think was put on the old board.