Here’s a test series using the 1,000 Watt-second, Speedotron Force 10, a full-featured AC-powered monolight. The Speedtron’s t.5 value is 1/850th, which is still long enough to permit sync speeds all the way up to 1/8,000th on a Nikon D800E. Note that results vary by camera type, even among the same manufacturer.

The Speedotron Force 10 is unique in that its moderately long t.5 flash duration remains constant across its entire power range. Typically, the longest flash duration for a studio strobe is only attained at its maximum power setting, becoming significantly shorter as power is decreased. This feature alone makes the Speedotron Force 10 monolight an optimal HyperSync performer, and comes with the added benefit of being a very powerful flash. While unfortunately, Speedotron discontinued the Force 10 a couple of years ago, these units may still be found on the used market.

According to PocketWizard’s Nikon D800E-specific Wiki page here, I’ve set the flash sync speed to “1/250s (Auto FP)” [custom menu setting ‘e’ bracketing/flash, menu ‘e1.’]. If you’re a Nikon owner, see PocketWizard’s Nikon-specific Wiki here. Canon owners, check here.

test 1: HSS/FP enabled

C1 screenshot annotated

Here again, the targets used are an 18% gray card on the left, and a sheet of laser paper (104 brightness) on the right. Note that exposure was set to reveal uneven exposure or clipping, rather than an “accurate” representation of actual reflectance.

f/16 @ 1/125th:

FORCE10-125-LABELED

f/11 @ 1/250th:

FORCE10-250-LABELED

f/8.0 @ 1/500th:

FORCE10-500-LABELED

f/5.6 @ 1/1,000th:

FORCE10-1000-LABELED

f/4.0 @ 1/2,000th:

FORCE10-2000-LABELED

f/2.8 @ 1/4,000th:

FORCE10-4000-LABELED

f/2.0 @ 1/8,000th:

FORCE10-8000-LABELED

conclusions:

• uneven exposure from top to bottom of frame.
• minimal light loss (light gain at bottom of frame).
• no “clipping” (i.e., no hard shutter-curtain shadow).

Note that a manual white balance was set to 5,560-degrees Kelvin in the Nikon D800E used above, and picture settings set to “neutral.” Starting at the 1/250th shutter speed, the image becomes slightly warmer as shutter speed increased even though strobe power remained constant.

As shutter speed increases, the lower part of the frame increases in exposure, as a result of an unevenly lit sensor. Again, this effect usually goes unnoticed in real-world photography. But most notably, there appears to be little to no loss in recorded flash output, and in fact a gain in exposure (though, undesired) is achieved in the lower part of the frame as shutter speed is increased. Also no hard shutter-curtain shadow appears throughout the entire range.

test set-up:

Below is a photo of the test set-up. A Nikon D800E with an AF-S Nikkor 50mm f/1.4G lens mounted. A PocketWizard TT1 transmitter is in the D800E’s hot-shoe:

FORCE10-SETUP-2

FORCE10-SETUP-3

Shown above is the Speedotron Force 10 monolight used, with the PocketWizard Flex TT5 transceiver attached via a 1/8″ mini-to-1/4″ phone sync cord. The strobe was bounced into a 7′ Westcott white umbrella, which was faced toward the gray and white targets. A neat feature of the Force-series monolights is their molded mounting track, which conveniently happens to fit the hot-shoe foot of the Flex TT5.

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