Since I have been shooting a lot of portraits lately at F2.8 during bright daylight hours, I have had to shoot using high speed sync to get the right exposure. The other day I photographed Tory, a model in town, and we were going for that selective focus look. Exposures of 1/1000 and faster at 2.8 were the norm. High speed sync confuses a lot of people, maybe it should be renamed “shallow depth of field sync”, or SDFS mode…or not! But anyone using flash and wanting selective focus at wide open apertures needs to master this technique. If you are a Nikon shooter you can set this mode in your custom functions in camera, for Canon shooters this option is on your flash. In high speed sync mode the flash is shooting a rapid burst of flashes so there is always flash occurring no matter where the shutter curtains are in the exposure. This allows you to shoot at any shutter speed, but it also reduces your flash range a lot, especially if you are shooting through an umbrella.
To help with the power issue I have been using the Lastolite Triflash bracket. After Lastolite provided me one for an article I was writing, I went right out and bought another. These brackets are really handy, allowing three TTL flashes to be mounted and shot through an umbrella. This greatly reduces recycle time and really helps when shooting in high speed sync. And if you are close enough, the optical slave will trigger all three flashes even though the optical eye isn’t facing the camera directly. Lastolite is coming out with a new version which will lock tight the TTL flashes in the bracket.
I used this set up for all the images here. For the images of Tory high on the staircase I used a manfrotto 24 foot lightstand to get the umbrella high enough.
Tech: Nikon D3, 45mm tilt shift lens, ISO 100, top shot 1/800 at F4.2, lower image 1/1000 at F2.8