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Ideas for cool Kinematics Photo

  1. Feb 22, 2010 #1
    i have to take a photo demonstrating a Kinematics Phenomena. I do one every unit but this unit is really sutmping me. For the optics unit i took a picture of a laser bending through glass, for waves i took a picture of light interfering through a diffraction grating, for electricity i took a picture of my motherboard (lame i know).

    I dont know what to do for kinematics, i was thinking of taking a picture of a basket ball in mid flight, but that doesn't show that much phenomena. any ideas?
  2. jcsd
  3. Feb 22, 2010 #2
    How much time do you have?

    You could put a collar, held in place by a spring, on a ball and socket bar.
    Put some kind of a light on the bar that will remain lit.
    Give the bar a whirl around the z axis, or whichever you deem to be straight up and down. A constant velocity would be nice but probably hard to accomplish.
    Take an overheard shot with a long exposure to get a picture of the motion of the collar as it moves in and out on the bar.
  4. Feb 22, 2010 #3
    The idea of taking a motion blurred image is a great idea... In my opinion though to make it more clear that it's an image of kinematics would be to take several shots (if you have a digital camera you can use the burst mode...) of the object in motion and then blend them together using photoshop...
  5. Feb 22, 2010 #4


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    Exactly. "A photo of kinematics" is an oxymororn. Unless you use a multiple exposure....
  6. Feb 23, 2010 #5
    Last edited by a moderator: May 4, 2017
  7. Feb 23, 2010 #6


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    Or take a picture of some light source in motion (could be something reflecting light as well), and accent it with a flash at the end. Not that that's much different from the blurred picture zomgwtf referred to.

    Edit: obviously vasara posted a picture while I was composing message, that's more or less what I am thinking about.
    Last edited: Feb 23, 2010
  8. Feb 23, 2010 #7

    Chi Meson

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    I'm curious. You did optics first? Was this the textbook order? Or did the instructor start at the back of the book?

    WHen I think of kinematics, I think of blocks sliding down ramps. So if it has to be a static shot, then you could go for that or similar iconic image. The basketball image is fine too, especially if you show the shooter, the ball and the basket.
  9. Feb 23, 2010 #8
    @Vasara, did you take that picture yourself? im not exactly sure what you mean when you are describing how to shoot something like that (im not a big photographer, i only really use a point and shoot).

    @Chi Meson, yea our curriculum is taught sorta backwards.
  10. Feb 23, 2010 #9
    You would use this in an area with little lighting (preferably none) and then proceed to take a picture as normal. The only difference being in the way the camera Flash goes off. The way it normally happens is the shutter opens and the flash goes off shutter stays open a bit and then shuts.

    The way a 2nd curtain sync flash will work is the flash goes off prior to the shutter opening then goes off again before it closes.
  11. Feb 23, 2010 #10
    There's always the 'classic' bicycle wheel in motion showing that the tangential velocity at the ground is zero, at the pin is V, and at the upper edge is 2V. This can be seen by the transition of the wheel's exposure going from 'unblurred' at the ground to blurred at the pin to 'very blurred' at the upper edge.
  12. Feb 24, 2010 #11


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    Just note that 2nd curtain sync available in most cheap cameras, IIRC they mostly do 1st curtain sync. Effect on the picture will be very similar.
  13. Feb 24, 2010 #12
    Yeah, they'll either do a front or rear curtain, not both.
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