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For the black and white fans

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  • #16
    Re: For the black and white fans

    Originally posted by Jan View Post
    Hi Tim,

    excellent job !

    May I ask, how you got so many reflections on the prop ?

    (GER)
    I'm not Tim, but I can come up with a theory:. ;-)

    First, there are obviously multiple light sources- several Sodium ramp lights on towers at various locations around the ramp? A few look significantly brighter than others. implying that these are the closest ones. The geometry between camera, prop "disk," and each individual light would give exactly one 'spark' from prop hub to the tip IF the exposure duration was such that only one blade passed between the camera and the sodium light source. Since the prop blade is a curved surface, the image of the sodium traces out a streak from hub to tip as the blade cuts across between the camera and light. Since the pitch is opposite on the front and rear prop blades, they produce very different reflection traces.

    Second, since the exposure is longer than one prop blade (I believe its almost exactly one ROTATION of the prop so that all 3 blades of each prop cut between camera and sodium), each individual BLADE of the 3 on each prop creates its own "arc" of light. Subtle differences in the blades mean that each lamp image produces 3 very sightly different arcs grouped tightly together.

    So- for each sodium light, there's a cluster of "arcs" for each front prop blade and each rear prop blade. For each cluster, there is an individual trace of each of the 3 blades on that prop.

    Thinking this way is the curse of the engineer... Everyone else gets to say "oh, pretty" and get on with their day. I have to say, "oh, now WHY...." and waste 45 minutes thinking.

    Oh, and maybe because I stared at it so long, this is so far my favorite photo from Reno this year.
    Last edited by 440_Magnum; 10-02-2012, 08:35 AM.

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    • #17
      Re: For the black and white fans

      Now that was a great post, Magnum! I've had a crappy 24 hours (death in the family, gonna have to be away for a week or so to help deal with it , trying to coordinate my getting to Oregon from Canada and Birgitta from Death Valley etc etc) and I open up my computer and immediately get a huge belly laugh.

      I needed that!

      Thanks for making my day better. And, wonderful photograph, Tim...

      Neal

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      • #18
        Re: For the black and white fans

        Originally posted by wingman View Post
        Now that was a great post, Magnum! I've had a crappy 24 hours (death in the family, gonna have to be away for a week or so to help deal with it , trying to coordinate my getting to Oregon from Canada and Birgitta from Death Valley etc etc) and I open up my computer and immediately get a huge belly laugh.

        I needed that!

        Thanks for making my day better. And, wonderful photograph, Tim...

        Neal
        Neal,

        My deepest condolences. I'm very sorry to hear the bad news. Safe travels to you and Birgitta.

        And as for the glimpse into my brain, now you see why I could never be an artist. And its funny because its totally true! :-p

        -Steve
        Last edited by 440_Magnum; 10-02-2012, 10:48 AM.

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        • #19
          Re: For the black and white fans

          Well done Tim as always, was that at dusk? That is what I'm trying to get with my C-140A...

          Lynn

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          • #20
            Re: For the black and white fans

            Originally posted by Hawker Driver View Post
            Well done Tim as always, was that at dusk? That is what I'm trying to get with my C-140A...

            Lynn
            Yes it was.

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            • #21
              Re: For the black and white fans

              Originally posted by 440_Magnum View Post

              (...) multiple light sources (...) several Sodium ramp lights (...)
              Thanks Magnum for accelarating my sleepy brain in the needed way.
              You should be right. Didn´t thought about artificial light at my first try.
              Jan

              http://www.AirRace.info = http://www.airrace.de

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              • #22
                Re: For the black and white fans

                Mind if I put that on my computer desktop?
                That is truly mesmerizing.

                Tim

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                • #23
                  Re: For the black and white fans

                  That's not an issue.

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                  • #24
                    Re: For the black and white fans

                    Originally posted by 440_Magnum View Post

                    Second, since the exposure is longer than one prop blade (I believe its almost exactly one ROTATION of the prop so that all 3 blades of each prop cut between camera and sodium)
                    With a 10 second exposure, that a lot more than one rotation for each blade... a lot more.
                    Bill Garnett
                    InterstellarDust
                    Air Race Fanatic since 1965

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                    • #25
                      Re: For the black and white fans

                      OK Tim, I keep coming back and looking at this photograph. It is gorgeous.

                      I've been to your web site, but can't figure out how to buy a print. Please email me. bill@interstellardust.com
                      Bill Garnett
                      InterstellarDust
                      Air Race Fanatic since 1965

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                      • #26
                        Re: For the black and white fans

                        Originally posted by Bill@Interstell View Post
                        With a 10 second exposure, that a lot more than one rotation for each blade... a lot more.
                        I missed the shutter time. In that case, there are 3 streaks for each sodium light because each of the 3 blades on the front and rear props traces its unique profile every time it goes by. Remarkable that everything holds that stable while spinning- I'd think that little bits of blade flex would alter the trace of the reflection.

                        Tim- Put up the color version! I love the blue exhaust flames that are more clearly visible in it.

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                        • #27
                          Re: For the black and white fans

                          Here it is.

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                          • #28
                            Re: For the black and white fans

                            Originally posted by T. Adams View Post
                            Here it is.
                            Awesome. Just that faint hint of blue fire... I love B&W, but I've gotta say I prefer the color in this case. Thanks for sharing it with us!

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                            • #29
                              Re: For the black and white fans

                              Another.

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                              • #30
                                Re: For the black and white fans

                                Another terrific shot Tim!

                                This must have been early in the week as the sun is way up and there aren't 9 millin green vests in the shot.
                                Bill Garnett
                                InterstellarDust
                                Air Race Fanatic since 1965

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