What's up with the drumsticks?

cletus

Snapped a few pictures at the JD McPherson show last Friday (if you don't know who JD McPherson is, stop reading this, go to your favorite on-line music vendor and buy a copy of Signs and Signifiers - I'll wait for you). I noticed something odd about one of my shots of drummer Jason Smay:




Take a look at the drumsticks:


It sure looks to me like a stroboscopic effect. The shutter speed was 1/20s and I count about forty copies of the drumsticks. That works out to something in the neighborhood of 800Hz. My guess is that at least some of the lighting is controlled by a switching power supply that doesn't bother with smoothing the power going to the lights. I guess it could be some kind of interaction between the slow shutter speed, low light, fast action and the CCD, but I've not heard of anything like that causing a strobe effect.

edit: It's probably a lighting system that controls levels via pulse width modulation.
Thoughts?

ziggy53

Yes, this looks like an effect caused by lighting powered by a faster frequency than line voltage, half-cycle AC power source (so missing a half-cycle). Beyond that, it's pretty difficult to determine exactly what system they might be using.

Perhaps contact and ask them?

http://www.jdmcpherson.com/contact.html

cletus

ziggy53 wrote: »

Yes, this looks like an effect caused by lighting powered by a faster frequency than line voltage, half-cycle AC power source (so missing a half-cycle). Beyond that, it's pretty difficult to determine exactly what system they might be using.

Perhaps contact and ask them?

http://www.jdmcpherson.com/contact.html

Thanks Ziggy. I thought about this some more today and I'm 99% positive the at least some of the lighting was LED based, and thus would use PWM for level control. I might contact the venue and see if I can learn more about their setup (JD and the gang don't travel with lighting equipment... they just use what the venue provides)