Overread, I'm thinking that if the power was boosted, then the pulse length would increase, and Mishele won't be getting the extreme sharpness (in terms of time) that she is getting. When I did these kind of shots, I found that there is blur at full power, and you need to shoot at 1/64 or evern 1/128 full power to get the extremely short flash duration. Also found out that if you try to shoot two flashes, it is very hard to get them to sync exactly right (given that the pulse lengths are so short) - so I would get two images instead of one lit from two sides...