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SrRd_RacinG 12/29/19 7:31:01 PM #1: |
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keyblader1985 12/29/19 7:33:43 PM #2: |
Pretty sure it's just ascending into Heaven.
--- Official King of PotD You only need one T-Rex to make the point, though. ~ Samus Sedai ... Copied to Clipboard!
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joemodda 12/29/19 7:35:28 PM #3: |
So when is Elon going to invent some dank hoverboards for us peasants?
--- The sin is not in being outmatched, but in failing to recognize it -Ancestor ... Copied to Clipboard!
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TheWorstPoster 12/29/19 7:36:51 PM #4: |
Turn it into one of those Topic > Board .gifs we used o do a long time ago, or whatever they were.
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Sahuagin 12/29/19 7:41:47 PM #5: |
pretty sure it's more related to compression and/or image stabilizing. I saw a similar effect watching a bicycle video where the front tire appeared to almost be motionless except for turning forward an inch or two once every few seconds. the speed of the tire should be fluctuating a lot, so it's not synchronized with the camera. the compression on the video is just reducing something that is otherwise super hard to compress due to the amount of noise involved into something extremely easy to compress since it's no longer moving frame to frame.
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SrRd_RacinG 12/29/19 7:42:41 PM #6: |
Similar to the flashing LED lights scenario. I recall seeing a video for a Corvette (years ago), when LED was becoming THE thing. I'm like, wtf, that's embarrassing to show on your Youtube channel- a video of your car's tail light flickering like crazy. It's not a malfunction or faulty connection. They do actually flicker, but too fast for the naked eye.
However, the camera sees all! --- ... Copied to Clipboard!
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Mead 12/29/19 7:52:19 PM #7: |
great magneto broke out of his cell again
--- Lemonheads ... Copied to Clipboard!
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SrRd_RacinG 12/30/19 10:58:45 AM #8: |
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Energy Surge 12/30/19 11:30:54 AM #9: |
Sahuagin posted...
pretty sure it's more related to compression and/or image stabilizing. I saw a similar effect watching a bicycle video where the front tire appeared to almost be motionless except for turning forward an inch or two once every few seconds. the speed of the tire should be fluctuating a lot, so it's not synchronized with the camera. the compression on the video is just reducing something that is otherwise super hard to compress due to the amount of noise involved into something extremely easy to compress since it's no longer moving frame to frame. Compression wouldn't cause this at all. It's totally the video frame rate matching a specific rate of rotation of the object. A wheel with thirty-two spokes would be a lot easier to capture stroboscopic footage of than a helicopter with five propeller blades. You just need the frame rate to match a multiple of 1/32 the rotational speed of the wheel compared to a multiple of 1/5 the helicopter blades. There are many more opportunities to match the wheel compared to the helicopter. Even if you don't match the rotational speed, the video can still appear to show a very slowly moving rotating object if you get close to the ideal amount. The the wheel wasn't completely stationary as it progressed a couple inches every few seconds, so they weren't entirely synchronized to one of those multiples of the wheel. Here's a related video on the stroboscopic effect: https://www.youtube.com/watch?v=2SgG99QKLFE --- The only reason lightning never strikes in the same place twice, is that the same place isn't there the second time. ... Copied to Clipboard!
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rjsilverthorn 12/30/19 11:36:33 AM #10: |
Energy Surge posted...
Compression wouldn't cause this at all. It's totally the video frame rate matching a specific rate of rotation of the object. A wheel with thirty-two spokes would be a lot easier to capture stroboscopic footage of than a helicopter with five propeller blades. You just need the frame rate to match a multiple of 1/32 the rotational speed of the wheel compared to a multiple of 1/5 the helicopter blades. There are many more opportunities to match the wheel compared to the helicopter. Even if you don't match the rotational speed, the video can still appear to show a very slowly moving rotating object if you get close to the ideal amount. The the wheel wasn't completely stationary as it progressed a couple inches every few seconds, so they weren't entirely synchronized to one of those multiples of the wheel. I was looking for that video after seeing this thread, but I couldn't remember who had done it. ... Copied to Clipboard!
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Shadowbird_RH 12/30/19 12:15:46 PM #11: |
The holographic projector on that scout disk is malfunctioning. Looks like we're picking up some of their bad habits.
--- Fail, and we all face a tyrannical age of pizza the likes of which sentient life has never known. - Sun'barac, Xenoblade Chronicles X ... Copied to Clipboard!
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EvilMegas 12/30/19 12:18:28 PM #12: |
"It is my time, I am needed."
--- Official King of Black People https://imgur.com/Zk3VS3o http://imgur.com/a/UeQiE https://imgur.com/aSnCUuI ... Copied to Clipboard!
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Sahuagin 12/30/19 3:42:50 PM #13: |
Energy Surge posted...
Compression wouldn't cause this at all. <snip> why not? that's exactly the kind of thing compression does to simplify the image to compress it. here's an example. things to notice include:
for the helicopter, you're not literally getting raw frames that look identical frame to frame, you're getting frames that look similar frame to frame and the compression converts it into something that looks identical. --- ... Copied to Clipboard!
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Muscles 12/30/19 3:56:41 PM #14: |
I don't really know shit about cameras, but why does everything else seem to move, at least somewhat, normally? Shouldn't it look slowed down or kinda choppy like claymation?
--- Muscles Chicago Bears | Chicago Blackhawks | Chicago Bulls | Chicago Cubs | NIU Huskies ... Copied to Clipboard!
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TigerTycoon 12/30/19 4:06:26 PM #15: |
Saying the blades are moving at the same rate as the camera frames are just government lies to cover up this helicopter being abducted by aliens.
--- YOU COULDN'T AFFORD IT! ... Copied to Clipboard!
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JOExHIGASHI 12/30/19 4:11:02 PM #16: |
Sahuagin posted...
pretty sure it's more related to compression and/or image stabilizing. I saw a similar effect watching a bicycle video where the front tire appeared to almost be motionless except for turning forward an inch or two once every few seconds. the speed of the tire should be fluctuating a lot, so it's not synchronized with the camera. the compression on the video is just reducing something that is otherwise super hard to compress due to the amount of noise involved into something extremely easy to compress since it's no longer moving frame to frame.nah. its magic --- Next Xbox will be named Xbox1 2 ... Copied to Clipboard!
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_AdjI_ 12/30/19 5:53:50 PM #17: |
Muscles posted...
I don't really know shit about cameras, but why does everything else seem to move, at least somewhat, normally? Shouldn't it look slowed down or kinda choppy like claymation? This happens because the rotational frequency of the helicopter blades happens to line up with the framerate of the camera. The framerate isn't anything unusually high or low, and presuming the footage is played back at the same rate as it was recorded, there's no reason to expect anything else to look weird. ... Copied to Clipboard!
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ultra magnus13 12/30/19 8:07:21 PM #18: |
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Energy Surge 12/31/19 7:18:21 PM #19: |
Sahuagin posted...
why not? that's exactly the kind of thing compression does to simplify the image to compress it. I might agree compression is involved in causing this effect with the tire tread. When you described a bike wheel, I was imagining a stationary observer watching the bike roll past. The stroboscopic effect is also known as the wagon wheel effect as the spokes of a wagon wheel can do the same thing as propeller blades. I didn't imagine a scenario where the camera is looking at the tire treads which are held relatively stationary in a small part of the frame because the camera is traveling with the tire. Sahuagin posted... it can't be for the bicycle wheels though since they're not moving fast enough. The speed of the wheels doesn't need to be as fast as you think. Yes, an object could turn 360 degrees in one frame to create the effect. That video appears to be 25 fps, so that would require 1500 rpm for the wheel. I agree that's way too fast. But you pointed out the edge of the tread appeared motionless while the center of the tread didn't. For mountain bike tires, the edge of the tread is often lined with a repeating pattern of studs that repeats much more frequently than the studs along the center of the tread. Let's say there are fifty studs in the tread aloud the edge of the tire just to make the math simple. Because there are fifty identical positions, it could rotate as little as 7.2 degrees per frame to match the frame rate of the camera. That's only 30 rpm. And the wheel could turn any multiple of 7.2 degrees to reach another identical position. So any multiple of 30 rpm would make the studs on the tread appear motionless. 150 rpm is around 10-12 mph depending on the diameter of the tire. The studs along center don't repeat at the same rate so the effect doesn't manifest down the center of the tread. When they reach the top of the incline they're able to move more quickly and the rate of revolution is able to match one of the speeds capable of causing the center of the tire edge to repeat each frame. So I think I'll still argue this effect is present in your linked video, though I'm not completely sure. --- The only reason lightning never strikes in the same place twice, is that the same place isn't there the second time. ... Copied to Clipboard!
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Sahuagin 12/31/19 7:46:43 PM #20: |
Energy Surge posted...
Let's say there are fifty studs in the tread aloud the edge of the tire just to make the math simple. Because there are fifty identical positions, it could rotate as little as 7.2 degrees per frame to match the frame rate of the camera. That's only 30 rpm. And the wheel could turn any multiple of 7.2 degrees to reach another identical position. So any multiple of 30 rpm would make the studs on the tread appear motionless. 150 rpm is around 10-12 mph depending on the diameter of the tire.yeah k. I think I'm underestimating the speed of a camera shutter, and the visual similarity of the wheel from frame to frame. compression might be involved but now I have no idea to what degree if any. --- ... Copied to Clipboard!
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