stills of a golf ball in motion

[andnowimbroke]

I think my camera is getting roped into taking stills of a golf ball being hit off a tee. Is this going to be more of a shutter speed issue or a flash issue. They are probably going to use the 7D. How far down on the quality scale do you have to go to get the fastest shutter speed?Do they underexpose the background and use a flash to help freeze it?..or both, or is there a better option? I have no clue. I even thought about using video @ 60fps and then slowing it down in post and taking screen shots. I've only got two 8gig extreme III and am not sure if thats large/fast enough to pull it off. Any thoughts will be welcome.


Thanks,


Greg

[Daniel Browning]

This isn't my area of expertise, but I'm pretty sure that golf ball speeds are so high that you wont get a small enough blur before you hit rolling shutter artifacts (skew). Stopping motion with flash is definitely the best way to go, because then the sensor readout speed (which is slower than 1/8000) wont matter. I think you do have to underexpose the background or choose a background that is small and close enough to light with flash. You might need four or more flashes to get enough power (since they have to be on their lowest setting to get the lowest decay time, which is the highest stopping power.) Hope that helps.

[andnowimbroke]

Boy, I brought out all the heavy hitters! Thanks for the replies guys. Sorry I took so long to get back. I swung by work to check out the post after church today. I typically copy all new posts to a flash drive and read them at the house after I'm finished with whatever I get roped into for the day I was thinking about the speed thing and remembered Rob G.'s experiment with the 1DIV. I pulled out the old files of this runner sprinting towards the camera. At 1/8000 sec., her arms were usually at 90 degree bends from the previous picture. I don't know how fast she was running, but don't think her arms or legs were hitting 80MPH.


To answer a few questions I know for sure: This is a high school project (not mine) and was willing to donate my camera (7D) and the flash (580EXII). I snickered a bit when they talked about using a glorified P&S at first, but now I don't know if mine will be up to par(pun intended) either. I believe the girl who's project it is wants to do this at the driving range (outdoors) with her swinging the club. It sounds more like from the thread so far thatI need to use a pivot/bearing with a clamp and a low rpm motor/gravity for a controlled speed. I swear I've seen this done on TV before with reference lines and golf shaft flex/torque from the speed. I guess I have more appreciation for it now.


I do have access to metals of all shapes, machine lathes, drill press, a bunch of used pillow blocks and bearing, plasma torches, welders,.. you know, cool stuff, but like I said, I just kinda wanted to loan out my camera and get them started in the right direction. I worry that there I a puzzle to be sovled and it won't take a lot for me to dive in a bust out a Rube contraption.

[Geoff]

andnowimbroke -- Like others above have mentioned, this will be primarily a flash and trigger problem...not necessarily a shutter speed problem...depending on the specific composition of the photo that you're wanting to capture.


Are you looking for something like Doc Edgerton captured? See:


http://edgerton-digital-collections.org/?s=golf#hee-nc-35006


or something more like a full-bodied golfer hitting the ball at just the right moment:


http://edgerton-digital-collections.org/?s=golf#hee-nc-38111


For your school project, I would recommend studying Edgerton's notebooks that are online at the same site as the links above.





As for making your own photos, there are a lots of circuit designs available to trigger flashes with external events. If you're not up to the soldering and circuit board layout, there are also commercially available units that give a turn-key solution.





See for example:


http://www.cognisys-inc.com


another company that offers some of these triggers is:


http://www.bmumford.com/photo/camctlr.html





Hope this helps!

[andnowimbroke]

Geoff, those examples are great! 1/50,000 though. Ouch. I'm not real good at circuit crap, so I might lean towards a turn-key approach. I was thinking I was going to have toput a box at low speed in front of a high powered light source to get a strobe thing going on. I think to much.

[Sean Setters]

I think we need more information. Like...


Where will these shots take place? In an indoor driving range or outside? If outside, what part of the day?


What equipment do you have at your disposal? You mention flashes--how many and what kinds do you have? What is your flash triggering method?


Is this for a commercial shot (for use in advertising), or will these people actually be playing golf at the time?


Is it an absolute must that you freeze the point at which the club head strikes the ball? With such a high-speed action sequence, I think a small amount of motion blur at the point of impact might be nice...

[crosbyharbison]

It would probably be easier to do this in photoshop by combining a few different shots

[Bill W]

Greg....I actually have some experiencew/this shot.


My friend (editor for the UMASS yr book at the time....early 70's) wanted to catch a driver striking a golf ball for the lead in page to the Golf team. I had just graduated from college and still working on a golf course....this allowed us to do the shot at night on a tee that was nearly in a pitch black environment.


He drilled a couple holes in some tees to pass wires thru so the club/ball striking would connect the wires toignite the flash....yes, it worked and he did use the shot. From a golfer's perspective....I sliced it and had to take a stroke and distance.


I will be in touch w/him this week and ask him the particulars and pass the info onto you. He's a pro photographer and has always kept good records of his shots....I just hope he still has the particulars in a notebook or at least remembers.


Regards


Bill

[Shea Design]

A circuit through the tee seems workable for the flash.. Personally I like to build little gizmos and would look for kit or design a solution to trip the shutter ahead of the strike and let HSS handle the flash. A laser that is interrupted by the club shaft at 75% of the swing arc for example, set to release the shutter. I imagine a delay circuit could enable some simple calibration once the near range was established. Of course this assumes some degree of swing to swing consistency and is now doubt why you see so many robot golf swingers (look out bender).


If you want to control both exposure levels in the shot, meaning the ambient levels (or background) and those of the flash you might have to take a similar path.


Alternatively you could put 4 stops of filter on the lens and cable release the shutter manually, flashes full power, and see what your minimum shutter speed looks like.


If you really want to leverage HSS, say to 1/8000th, then a few electronics may be required. Remember shutter speeds like this require multiple flash fires synced to the exposed sensor area, as the first curtain chases the second.


If the shot is for an advert, then I would just shoot it like a product shot, cut and duplicate the ball and blend a motion blurred version into the comp. Or I could fire up 3D Studio Max and put Mental Ray to the task.


Look FWD to your progress.


-Shea

[Daniel Browning]

I don't know if HSS would work well in this situation. The delay between flashes may be too long, but if it isn't then it will show multiple images of the objects in motion, and that may not be desired (but I bet it would look cool).