I just did some Hyper Sync tests with the 300B, and Pocket Wizard ControlTL.
With power set at 30, the 300B delivered good exposure at 1/2000 F2.8 at ISO 200. The 300B had a 36" Octibox attached with both defusion panels. The front panel of the Octi was about 5 feet from the subject.
Given the nature of Hyper Sync, the F stop and shutter speed relationship is nearly linear. F 8 at 1/250 looked nearly identical. Interestingly, the defusion panel I used for a background shows the light fall off toward the left, which is consistent with less light as the flash output tail dims.
The image is SOOC, without any Lightroom manipulation. The white square on the color checker is a bit under exposed, the black square is right on the reference value. The image was import processed with my 5DII custom profile and a strong tone curve with zero black compensation.
If it doesn't rain tomorrow I should have time to do a test outside in real sunlight. The 1/2000 F2.8 at ISO 200 is just about equivalent to sunny 16 and there are two more stops of light available. My test with the 300B delivered F16 6/10 at 60 and F8 6/10 at 30.
And the battery keeps up nicely.
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