Paul C. Buff, Inc. Technical Forum

I admit, I'm confused.

I've read the relevant posts here. I understand the basic limitations of focal-plane shutters, the power-draining effects of camera manufacturer's "High-Speed FP Sync" feature, and the basic principle behind LPA Design's PocketWizard Hypersync feature (which, I know is different from High-Speed FP Sync). But LPA's Hypersync feature appears to perform differently with different bodies and different studio strobes.

A photographer's website located here: http://www.lebryk.com/category/pocket-wizard/ describes many Hypersync-photographed images, using a Dynalite Uni400JR strobe, attaining bar-free images at speeds up to 1/8,000th of a second with his D3s + MiniTT1 + FlexTT5. I understand that the E640 is a much more capable, more fully featured monolight than the Dynalight model mentioned, but if this isn't possible with the D3s/E640 combination, I would consider the Dynalite instead just for this capability alone.

In another photographer's blog, located here: http://tombolphoto.com/blog/elinchrom-ranger-using-pocketwizard-hypersync-18000-sync-speed-possible/ he indicates that while he was only able to attain Hypersync images at no more than 1/320th using a D3, he was able to attain a 1/8,000th of a second sync with his D300 and an Elinchrom Ranger.

So, since the maximum, bar-free, Hypersync sync speed is strobe-dependent, and the maximum sync speed appears to vary widely among both different manufacturer's strobes, and differing camera bodies, I was wondering what my particular D3s/MC2/E640 combination would yield.

I was very much hoping to attain high sync speeds with the Einstein E640s + PowerMC2 combination, used with my Nikon D3s and MiniTT1. Has anyone here ever "calibrated" a Nikon D3s + MiniTT1 + MC2 + E640 using the PocketWizard firmware utility, and attained any sync speeds significantly higher than 1/250th?

Thanks for any replies!

I know we spoke on the phone regarding this issue, however, I will answer here in order to assist others with the same question.

First, I should ask what a user's intensions are. The biggest benefit (from my personal observations) of Hypersync technology is to use higher shutter speeds to stop action in high ambient light conditions while also using flash, or to use faster shutter speeds to compensate for wider apertures in high ambient light. Obviously, the wider apertures are used for shallow DoF, typically in portraits.

In low light environments (as many or all of the photos in the links were, at least not Sunny 16 days), action freezing is easily achieved with flash duration rather than shutter speed. Einstein has extremely fast flash durations, and is very well suited for action stopping when the ambient light is somewhat low (low enough so that the necessary shutterspeed is below your sync speed).

When using shutter speeds of x-sync or below, your entire frame is exposed at once, allowing for the entire frame to gather the same amount of light from the flash. When using any shutter speed above x-sync, only part of your sensor is exposed at any given time. It used to be that the flash was not triggered until the end of the exposure, where the first curtain made its full travel and the second curtain had already covered the sensor.

Now, with newer sync options, such as PW TT units, the flash is fired just before the first curtain opens (or at least just before the scond curtain starts to travel), and the flash burns while the shutter travels. There are two monkey wrenches that are thrown in here: 1-flash curve and 2-flash duration.

Flash curve is the decay in flash output. Flash output peaks very quickly, but kind of tapers off (except in Einstein, speedlites and a very few other mono lights). The initial exposed portion of the image will recieve the peak output, while the last exposed portions will recieve the tapered down out put. None of the frame recieves all of the output. The results in uneven exposure (which may or may not be noticable), and a reduced effective flash power.

Flash duration relates to how long the flash is burning. Most manufactures state the t.5 time, or time it takes for the flash to reach 50% intensity on the "down hill" side. This is typically less than 33% of the actual total burn time of the flash. So a typical flash with a stated flash duration of 1/600 will burn for at least 1/200 of a second. If your x-sync is 1/250, then the travel time of each curtain is also 1/250 regardless of "shutter speed". This means the curtain can travel its entire journey while the flash burns (but remember the intensity is not always the same).

Einstein, speedlites, and the other very few studio lights that have IGBT control will exhibit the same trail off as a regular flash when set to full power, however, at lower power, the trail gets shorter and shorter as the output is cut off (kind of like rolling to a stop vs. hitting the brakes vs hitting a wall). We state t.1 times for Einstein for this reason. This means 1/1000 flash duration is pretty much 1/1000. But at 1/1000 of a second, it will only burn for about 1/4 the total time the shutter travels. This will yeild in only 1/4 or so of the imge to recieve ANY flash exposure (though that 1/4 will be fairly even). This means on any given camera, Einstein will expose various amounts of exposed frame depending on the power setting. Also, there are different flash durations in Action vs Color mode, so that will also add a variable.

We do not have a real world idea as to what shutter speeds are possible, as we did not develop any camera specific product. On the other hand, Pocket Wizard does test with most or all cameras designed to be used for their products, and may be able to give you more specifcs.

Or get a cheap B1600...same older technology ;)
Lower power = longer tail for Hypersync to work in.

Are you firing the Einstein at full power? I'd think the PW Hypersync hack only works w/ the Einstein at full power since you get the full tail of light to stick the Hypersync window into...

Thank you for speaking with me on the phone this morning and clarifying the issue for me. Also, thanks for taking the time to write that very detailed and informative post, and for sharing your answer with others here. In my book, your customer service gets five stars! Bravo!

I dont know about the D3 but I have a 5DMKII and could not sync w/ pocket wizards more than 250th. I spoke with them, buff and LDP without luck. Then I played with the utility settings and changed my camera model to a 7D - funny now I can sync up to 2000th! Seems like an issue with pocket wizards timing settings.

If studio460 is concerned about action shots, then maybe a real experience might help. I shot hockey with 3 E640 across the rink. The ambient light was from "brand new" fluorescent lights, not more then 6 months old from a refurbishment.
Ambient was 1/60 at f4.
Einstein was 1/250 at f8 to f11 set at 1/2 power. Absolute stopped the motion. Without the flash, image was black. So the only light was from the Einstein, and in action mode was equivalent to about 1/2000 exposure.

WARNING
Avast antivirus posted virus warning on this link...

A photographer's website located here: hXXp://www.lebryk.com/category/pocket-wizard/ describes many Hypersync-photographed images,