Hi all,
I need some help. I'm using the Pentax 645Z in studio for dance photography, which means that my dancers are engaging in fast movement. The only ambient light is coming from the modeling lamps. The strobes are Alien Bees, both 400s and 800s.
The unretouched pics below show a marked amount of what I assume is flash ghosting on the dancers' feet (which are obviously the fastest moving thing in the frame). Interestingly, other fast-moving objects, such as hands, hems of skirts, hair, and even dust are nicely frozen, but none of that matters due to the unacceptable ghosting with their feet.
The 645Z is notorious for its slow sync speed of 1/125 sec. My reading of the
AB800 specs suggests that worst case I'm getting a t.1 flash duration of 1/550 seconds, and given my power settings I'm probably closer to 1/1000.
In an attempt to get the ghosting under control, with the dancer in red, I purchased and used the 75mm leaf shutter lens to get the shutter speed to 1/500, thus bypassing the 1/125 X sync of the Pentax, but her foot is still ghosting.
My questions:
1) Am I diagnosing this correctly? Is this ghosting or simply too slow a shutter speed?
2) if it is ghosting, is it being caused by the modeling lamps, or by the flash duration of the strobes?
If the problem is the strobes, will switching to Einsteins eliminate the problem? Based on my reading of the
specs (page 13) and my anticipated lighting requirements, they would let me get me to a t.1 of around 1/4000 seconds as opposed to my current 1/1000 or so. This is a pricey solution, but I'm willing to do it if it would solve the problem (and would be really bummed if I dumped that money into Einsteins and the problem persisted).
Any input would be welcomed. Thanks!