Index finger macro on a Nikon D60. I think I used about 2-5 second exposure time on each button-press. I used a really sturdy tripod. Highly recommend getting a remote exposure button for this kind of work, though lol. My current camera can be fully automated, however.
The original was uploaded to Flickr, but I gave up the account when they suddenly demanded money. Uploaded now to motivate Rolf B here to make more of these, since he lives in the zone. (I live too far south to film these now, sadly.)