You need to be careful not to confuse shutter speed (exposure time) and framing rate (frames per second). Standard video is 30 frames per second, way too slow to capture a swing sequence in any detail (the swing monitors run at several hundred frames per second). Ball impact (the whole thing) occurs in about 1/2000 of a second (0.5 milliseconds) and timing is everything. Even at 1/1500 of a second exposure time, timed just at impact, the shutter will be open for the entire impact/rebound process and all you would see is a blur.
Edgerton got his images by firing a very short duration strobe repeatedly very quickly with an open shutter on a film camera using a trigger system to start the strobe sequence. His contribution was the electronics that would fire the strobe repeatedly with equal duration pulses (for uniform exposures). This was work funded by the military to study projectile ballistics and target impact phenomena. The sequence is open the shutter on the camera (at an f-stop that won't significantly expose the film with a 1-second exposure), fire the gun with a break wire trigger (this was before lasers and diodes) directly in front of the target to trigger the strobe sequence around impact, and close the shutter. Each strobe pulse puts an image on the film of the event at the time each strobe pulse was fired. The golf swing analysis was 'for fun'. Dig out some old ballistics books if you want to read more about this. Edgerton is quite well known. He later joined with Gremershausen (sp?) and Grier to form EG&G, who specialize in high speed electronics.
Regards,
Alan Brooks
At 08:20 AM 1/25/03 -0500, you wrote:
Graham, That ought to be plenty fast enough. My Toshiba PDR-M65 will only go to 1/500th, but I believe mine will take a sequence (never tried it). Maybe yours will too. A sequence at that kind of speed might improve your odds.Bernie Writeto: [EMAIL PROTECTED] ----- Original Message ----- From: "Graham Little" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, January 25, 2003 3:55 AM Subject: Re: ShopTalk: 20 min talk > Bernie > > The manual says it takes pics at 1/1500th of a second. ie 0.000666 of a > second. I'm hoping the manual's right and that 1/1500th is fast enough. I > think it's the luck part that's more of the problem, as we know timing is > everything. I'll let you know how it goes. > > Cheers > Graham > > ----- Original Message ----- > From: Bernie Baymiller <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Saturday, January 25, 2003 12:44 PM > Subject: Re: ShopTalk: 20 min talk > > > > Graham, > > > > Don't think you will have a camera with a shutter speed fast enough to > catch > > what you want to see. Probably need at least 1/500th of a second and some > > luck. Edgerton's strobe pics were much faster...slow ones were 1/600th. > > Those 8 ball impact pics were all taken in about .0005 second (ball was on > > face for .0004 sec)...don't even want to figure that speed out. > > > > Not sure what you want me to agree with until I get time to look at the > > graphs...too late tonight. > > > > Bernie > > Writeto: [EMAIL PROTECTED] > > > > > > ----- Original Message ----- > > From: "Graham Little" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Friday, January 24, 2003 9:49 PM > > Subject: Re: ShopTalk: 20 min talk > > > > > > > Bernie > > > > > > As you say, just one of many explanations. I'm playing in a tournament > > next > > > month with this guy. It's a four day comp > > > played on four different courses, bus and trailer. I'll be trying to > take > > > some digi pics to try and get a look at what's happening with the swing > > and > > > the shaft. I just have to figure out exactly when to press the button! > > > > > > Cheers > > > Graham > > > > > > ps do you agree with my interpretation of the graphs? > > > > > > > > > > > > ----- Original Message ----- > > > From: Bernie Baymiller <[EMAIL PROTECTED]> > > > To: <[EMAIL PROTECTED]> > > > Sent: Saturday, January 25, 2003 9:17 AM > > > Subject: Re: ShopTalk: 20 min talk > > > > > > > > > > Graham, > > > > > > > > > I've been working with a strong hitter, late release, 10 handicapper > > and > > > > he > > > > > wanted to try out a softer shaft. Result: low slice. Obviously > similar > > > > > things going on as in the Hackman photo. > > > > > > > > Not necessarily. Here's another possibility: If his swing path is > inside > > > out > > > > (maybe because he took the club back a little too much inside and laid > > it > > > > off a little on top) and club is headed right of the target line, but > > > timing > > > > is OK and head is ahead and closing, as in the BJ pics, then a hit > > toward > > > > the heel would cause a low, gear effect slice that starts almost on > the > > > > target line (because of the bulge redirection) and fades right. A > > center > > > > impact on this swing path would have been a straight, but blocked > right > > > > shot. There are lots of ways to hit a slice and I've found them all. > :-) > > > > > > > > Bernie > > > > Writeto: [EMAIL PROTECTED] > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
