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  • Probably a dumb question

    When you see a finish photo, they often add horizontal lines from the torsos of the finishers to precisely show the order of finish and the gaps between the runners.

    But surely the final placings don’t depend on where the runners were the instant the winner crossed the line. For example, whoever is in 3rd place at that moment might move up to second in the run-in.

    Please explain this to me.

  • #2
    Someone else can probably explain it better, but I believe the published finish photo is actually a composite of individual photos taken the instant that each runner passes the finish line beam. so the gaps between the runners do not reflect where they were when the winner crossed the finish. The lines are added to mark the torso cross and extend to the timer scale.

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    • #3
      Exactly as WRC explained. Here is the photo finish from the men's 100m in Doha

      You can see the lines correspond with the times on the x-axis

      M_100_f_1.jpg

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      • #4
        Thanks gentlemen. Makes perfect sense, should have thought of that myself!

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        • #5
          As I understand it, the photo finish is a composite of photos taken from a camera that only captures a very small slice of the finish line. It takes 3000 photos a second that only includes the finish line, then lays them next to each other. That is why you get some wonky effects of body parts looking elongated or truncated. Sometimes a trail leg takes somewhat longer to come through the finish line, thus looking really long like lanes 1 and 8.

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          • #6
            Originally posted by mcgato View Post
            As I understand it, the photo finish is a composite of photos taken from a camera that only captures a very small slice of the finish line. It takes 3000 photos a second that only includes the finish line, then lays them next to each other. That is why you get some wonky effects of body parts looking elongated or truncated. Sometimes a trail leg takes somewhat longer to come through the finish line, thus looking really long like lanes 1 and 8.
            Yes, you are exactly right. Bottom line is that the photo finish shows each runner as they "hit" the finish beam.

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            • #7
              Originally posted by mcgato View Post
              It takes 3000 photos a second
              I know the system has .0001 sec capability, but I still defy the human eye to see a bone (scapula vice humerus) INSIDE the body when the torso is twisted and the shoulder/arm is the first part to the line - remembering that no part of the arm counts.
              Atticus
              Senior Member
              Last edited by Atticus; 04-12-2021, 03:58 AM.

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              • #8
                Originally posted by Atticus View Post
                I know the system has .0001 sec capability, but I still defy the human eye to see a bone (scapula vice humerus) INSIDE the body when the torso is twisted and the shoulder/arm is the first part to the line - remembering that no part of the arm counts.
                Get back to me when you've solved the discus measuring conundrum...

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                • #9
                  Originally posted by gm View Post
                  Get back to me when you've solved the discus measuring conundrum...
                  Yeah, don't get me started. HS marks are + 3 feet. I've seen college markers miss by a lot several times in a meet because they're coming from 30' away . . . at a walk. The idea of centimeters is ludicrous till you get to the really big meets. Unless you've got an experienced, dedicated OFFICIAL (as opposed to a kid with popsicle sticks!), good-effin-luck.

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                  • #10
                    Originally posted by Atticus View Post
                    I know the system has .0001 sec capability, but I still defy the human eye to see a bone (scapula vice humerus) INSIDE the body when the torso is twisted and the shoulder/arm is the first part to the line - remembering that no part of the arm counts.
                    I've been on photo-finish teams in the UK when people have split 2 athletes based on assumptions and interpolations that I wouldn't be happy trying to defend to an athlete/coach/parent etc.

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                    • #11
                      Originally posted by Trickstat View Post
                      I've been on photo-finish teams in the UK when people have split 2 athletes based on assumptions and interpolations that I wouldn't be happy trying to defend to an athlete/coach/parent etc.
                      There are timers who have trained/precise eyeballs, but it's still guesswork where the shoulder ends and arm begins in torso-twisted finishes. .0001 represents a little over ¼ inch at 10.00 100m speeds.

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                      • #12
                        Originally posted by Atticus View Post
                        There are timers who have trained/precise eyeballs, but it's still guesswork where the shoulder ends and arm begins in torso-twisted finishes. .0001 represents a little over ¼ inch at 10.00 100m speeds.
                        Having cameras both inside and outside the track can help a lot but I doubt even with that you can differentiate to a 1/4 inch. 1 inch with very good resolution perhaps but not a 1/4 inch.

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                        • #13
                          I have long observed that we measure and time "guestimates" with great precision. Timers have to contend with clothing and distorted body parts. The vertical jumps are probably the most accurately measured but, even there, a jumper may benefit or lose by a lucky bounce. Thrown implements leave an imprecise impression or gash subject to whim/expertise of the marker. Horizontal jump impressions are frequently iffy, even in the best-prepared pits.

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                          • #14
                            Finishlynx photos are especially fun when the runner steps on the finish line.

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                            • #15
                              Originally posted by cigar95 View Post
                              Finishlynx photos are especially fun when the runner steps on the finish line.
                              Known in the UK as 'ski foot'.

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