by geckzilla » Fri Jul 19, 2019 6:25 pm
TheOtherBruce wrote: ↑Fri Jul 19, 2019 3:33 pm
toneyvr wrote: ↑Fri Jul 19, 2019 3:15 pm
The shadows are all over the place - I presume the stitched photos were from considerably different dates?
Can't be all that different, they were only out on the surface for a couple of hours, so the sun would barely move. What you're seeing is perspective effects — I've read a pretty thorough explanation on the
Bad Astronomy website, but in rough terms, the camera lens is set to a different focal length than your eyes, so perspective and the apparent direction of vanishing points are a bit off from what you'd expect to see.
And don't forget, it is a panorama view; the direction of the sunlight relative to where the camera's pointing is very different between the left and right edges of this composite picture. You can see the same effect here on earth when you use a camera with a "panoramic landscape" setting.
Here's an example of a panorama taken at Racetrack Playa:
Racetrack Playa Pano by
SoundSpeeds, on Flickr
What's great about this is that the rock has traced a path across the landscape, showing how a straight line looks curved in a panorama. All the shadows are essentially straight lines pointing toward the Sun, but they're also curved because they follow the geometric mapping of the panorama, not straight paths to the Sun, even though they do point toward it in reality.
[quote=TheOtherBruce post_id=293847 time=1563550435 user_id=144738]
[quote=toneyvr post_id=293846 time=1563549336]
The shadows are all over the place - I presume the stitched photos were from considerably different dates?
[/quote]
Can't be all that different, they were only out on the surface for a couple of hours, so the sun would barely move. What you're seeing is perspective effects — I've read a pretty thorough explanation on the [url=http://www.badastronomy.com/index.html]Bad Astronomy[/url] website, but in rough terms, the camera lens is set to a different focal length than your eyes, so perspective and the apparent direction of vanishing points are a bit off from what you'd expect to see.
And don't forget, it is a panorama view; the direction of the sunlight relative to where the camera's pointing is very different between the left and right edges of this composite picture. You can see the same effect here on earth when you use a camera with a "panoramic landscape" setting.
[/quote]
Here's an example of a panorama taken at Racetrack Playa:
[url=https://flic.kr/p/c3QSkG][img]https://live.staticflickr.com/7092/7252092158_263a710f12_z.jpg[/img][/url]
[url=https://flic.kr/p/c3QSkG]Racetrack Playa Pano[/url] by [url=https://www.flickr.com/photos/tronjohn/]SoundSpeeds[/url], on Flickr
What's great about this is that the rock has traced a path across the landscape, showing how a straight line looks curved in a panorama. All the shadows are essentially straight lines pointing toward the Sun, but they're also curved because they follow the geometric mapping of the panorama, not straight paths to the Sun, even though they do point toward it in reality.