Strobist Speed effect with my Son

Strobist info: moderate long exposure with rear curtain flash, going from wide to tele with a 17-50 zoom. SB-900 at camera right, triggered with built in D300 flash on comander mode. background -1EV, flash TTL +0.7EV. Inspired by the fantastic McNalliy's book 'Hot Shoe Diaries'

Done