Another related video I thought was really interesting (and goofy) to watch was one of a helicopter that rises but with its blades seemingly stationary: https://youtu.be/jWIcVP6GRfw?si=MaHmferJAT9BESz2
I believe this occurs because the shutter speed of the camera is the same as the speed of the blades making a full revolution. If I remember correctly, EE120 has a homework problem that explores this phenomenon and I highly encourage anyone interested in the topics covered in this lecture to check it out (although I think these topics are covered in the later parts of the course)
Yeek2
I'm not quite sure if this is the same as this video, but I think it's relevant to camera sampling in general, is this video here https://youtu.be/dNVtMmLlnoE?si=zXiibal3NvOy5XoK which covers rolling shutter, which I suppose is a form of sampling artifacts since (in the video) the rolling shutter isn't fast enough to keep up with things like a propeller, and as a result artifacts form.
sylviacx
I think long exposure is an interesting example of how images can be manipulated using very slow shutter speed (https://capturetheatlas.com/long-exposure-photography/). The long exposure technique can be used to "paint" using light, where the artifacts generated from really low sampling actually creates something intended for the piece.
AlsonC
@sylviacs this is really interesting! I took a look at your article, and I found it interesting how a longer exposure can make an image 'come to life.' I find it similar to how timelapses piece together images drawn out to show a long period of time in a short amount of time.
sjukurnael
@sylviacs I just read your article and I must say it is the first time I learned about long exposure, it's definitely cool that the way it works is not by "freezing" a particular moment (this is how I usually imagine what a camera does), rather, it captures the flow of time in a single image. I like how the article said that by keeping the shutter open for a longer time, we might capture details that might be impervious to the naked eye. This made me curious, perhaps this technique is very frequently used when people take pictures of the Northern Lights, and maybe if we go and see these lights for ourselves it won't be the same as what we see captured in pictures as they use long exposure. It's also interesting to note that the outcomes of long exposure photography are crafted through careful technique rather than post-processing.
aravmisra
@sylviacs thank you for sending the link to the article! I was really interested in this concept of long exposure, especially having seen many art pieces create with it (some with manually "drawn" letters of light, and some of scenery/stars. I was initially struggling to understand this concept of long exposure not really freezing a moment as a more intuitive understanding of what a camera does but rather displaying the passage of time, as @sjukurnael said. I thought that this article was pretty helpful in explaining it: https://www.nfi.edu/long-exposure-photography/ (it also has a couple ads for specific camera equipment, which I suggest to ignore). I also appreciated some of the notes in the two articles about how photographers can manipulate shutter speed and aperture to play with how the photos turn out. I would recommend anyone who has a bit of time, to read these sections as it's quite interesting, and I think a lot of phones nowadays even have settings you can manipulate to emulate that.
stang085
This reminds me of a video I've seen about making the illusion of water flowing backwards into faucets. This involved playing loud sounds/frequencies to create separation in the water, and then slightly changing the frame rate to capture the water going back into the faucet. A cool way to do practical effects without CGI
sgk12
@sylviacs Thanks so much for sharing that article! I've always wondered how certain pictures of the night sky are able to capture the orbits of stars as an arc of light — the article really clarifies how long exposure photos capture the passage of time. https://fstoppers.com/astrophotography/how-astrophotographers-shoot-very-long-exposures-568277 This was an interesting read about how computer-aided telescopes specifically use long exposure in astrophotography — some can use exposure lengths of up to twelve hours!
Another related video I thought was really interesting (and goofy) to watch was one of a helicopter that rises but with its blades seemingly stationary: https://youtu.be/jWIcVP6GRfw?si=MaHmferJAT9BESz2
I believe this occurs because the shutter speed of the camera is the same as the speed of the blades making a full revolution. If I remember correctly, EE120 has a homework problem that explores this phenomenon and I highly encourage anyone interested in the topics covered in this lecture to check it out (although I think these topics are covered in the later parts of the course)
I'm not quite sure if this is the same as this video, but I think it's relevant to camera sampling in general, is this video here https://youtu.be/dNVtMmLlnoE?si=zXiibal3NvOy5XoK which covers rolling shutter, which I suppose is a form of sampling artifacts since (in the video) the rolling shutter isn't fast enough to keep up with things like a propeller, and as a result artifacts form.
I think long exposure is an interesting example of how images can be manipulated using very slow shutter speed (https://capturetheatlas.com/long-exposure-photography/). The long exposure technique can be used to "paint" using light, where the artifacts generated from really low sampling actually creates something intended for the piece.
@sylviacs this is really interesting! I took a look at your article, and I found it interesting how a longer exposure can make an image 'come to life.' I find it similar to how timelapses piece together images drawn out to show a long period of time in a short amount of time.
@sylviacs I just read your article and I must say it is the first time I learned about long exposure, it's definitely cool that the way it works is not by "freezing" a particular moment (this is how I usually imagine what a camera does), rather, it captures the flow of time in a single image. I like how the article said that by keeping the shutter open for a longer time, we might capture details that might be impervious to the naked eye. This made me curious, perhaps this technique is very frequently used when people take pictures of the Northern Lights, and maybe if we go and see these lights for ourselves it won't be the same as what we see captured in pictures as they use long exposure. It's also interesting to note that the outcomes of long exposure photography are crafted through careful technique rather than post-processing.
@sylviacs thank you for sending the link to the article! I was really interested in this concept of long exposure, especially having seen many art pieces create with it (some with manually "drawn" letters of light, and some of scenery/stars. I was initially struggling to understand this concept of long exposure not really freezing a moment as a more intuitive understanding of what a camera does but rather displaying the passage of time, as @sjukurnael said. I thought that this article was pretty helpful in explaining it: https://www.nfi.edu/long-exposure-photography/ (it also has a couple ads for specific camera equipment, which I suggest to ignore). I also appreciated some of the notes in the two articles about how photographers can manipulate shutter speed and aperture to play with how the photos turn out. I would recommend anyone who has a bit of time, to read these sections as it's quite interesting, and I think a lot of phones nowadays even have settings you can manipulate to emulate that.
This reminds me of a video I've seen about making the illusion of water flowing backwards into faucets. This involved playing loud sounds/frequencies to create separation in the water, and then slightly changing the frame rate to capture the water going back into the faucet. A cool way to do practical effects without CGI
@sylviacs Thanks so much for sharing that article! I've always wondered how certain pictures of the night sky are able to capture the orbits of stars as an arc of light — the article really clarifies how long exposure photos capture the passage of time. https://fstoppers.com/astrophotography/how-astrophotographers-shoot-very-long-exposures-568277 This was an interesting read about how computer-aided telescopes specifically use long exposure in astrophotography — some can use exposure lengths of up to twelve hours!