Results of Flash Duration Measurements on My Various Strobes

I got a flash duration meter this year and I figured since I already took the time to collect this data you guys might want to see it too. Note that I have a graph of all my flash units compared to each other but all the plots of individual flash pops are from the Flashpoint Xplor 600 TTL because I wasn't clever enough to think of screenshotting the flash duration meter display until then.

The units under test are:

1) Norman P2000D which is a 2kJ pack+head system. I have the dual-tube head, so I can go up to 4kJ. That's 4000 Watt-seconds, for those of you that don't speak SI or the equivalent of 20 of the Flashpoint Evolv 200/Godox AD200 speedbricks.

2) Norman P800D 800J pack+head system

3 and 4) Paul C Buff Einstein E640 in both Color and Action modes

5) Flashpoint Xplor 600 TTL

That's all the flash systems I own. If anyone wants to show up in Central Ohio with their flash units, I'll test them as well and add the data to the plot and post.

First up is the combined plot of all the things I tested. The vertical axis is time in seconds and the horizontal axis is the electrical input power (in Joules, aka Watt-seconds) on a log base 2 scale (otherwise the low power end of the graph just bunched up silly). Most interesting thing to me is how clear it is which units use IGBT technology and which don't.

2366 x 1044

EMBED PREVENTED, IMAGE TOO LARGE: https://i.imgur.com/Uu​nER7K.png Click here to see our image rules.

Interesting to see your measurements, vs. what Buff claims for the Einstein...

Flash Duration (t.1) - in Action Mode or in Color mode: 1/588 sec. (at full power)

Tx for sharing your findings.

. . a link to another thread that included similar info on the Jinbei HD600v / early Rovelight 600B and a 580ExII Speedlite (and, indirectly, other flashes too):
https://photography-on-the.net …showthread.php?​p=17694712

Wilt wrote in post #18505657
Interesting to see your measurements, vs. what Buff claims for the Einstein...

Flash Duration (t.1) - in Action Mode or in Color mode: 1/588 sec. (at full power)

It requires a lot more information to determine the relative accuracy of the Buff result and the OP's result.

Would be useful to know which measuring device the OP is using.

Sekonic apparently has the capability built into some of its newer flash meters to read out duration.

The graphs offered by OP suggest something a bit more sophisticated.

Its useful information on a relative basis not sure how to evaluate it on an empirical basis without knowing a lot more about measuring device and method.

That's why I said it was 'interesting', since the details are lacking...what aroused my curiosity, to check one manufacturer's claims vs. his test results. were the relatively long duration measurements for the Full Power measurements, about double what I would expect to see.

dmward wrote in post #18505755
The graphs offered by OP suggest something a bit more sophisticated.

yes, if OP 'd be so kind to share the setup please ?!

Jeeze you guys are antsy! A guy can't even get any sleep around here

The meter is a Lumu Power.

Early on when I first bought it, I compared blur on a rotating striped disc between a measured flash duration reading and the same duration (using an electronic shutter that had been calibrated by a shutter tester) of continuous exposure as a poor-man's calibration check. The Lumu's flash duration numbers seemed in close agreement with the continuous.

If I happen to remember tonight, I'll re-check the full power duration on both of the Einsteins I have.

williaty wrote in post #18505894
If I happen to remember tonight, I'll re-check the full power duration on both of the Einsteins I have.

It would also be interesting to see the reported values for t0.1 from the Xplor 600's own LCD display, compared to the above measurements taken by your Lumu Power

Wilt wrote in post #18505906
It would also be interesting to see the reported values for t0.1 from the Xplor 600's own LCD display, compared to the above measurements taken by your Lumu Power

There's a video on youtube of someone scrolling through the power settings showing that data. I'm not going to waste time typing it out.

williaty wrote in post #18505926
There's a video on youtube of someone scrolling through the power settings showing that data. I'm not going to waste time typing it out.

https://www.youtube.co​m/watch?v=hFEHZYxrPsc

Summary: my measured values are actually faster than what the light claims except at minimum power. The differences are relatively small and insignificant though.

williaty wrote in post #18505926
There's a video on youtube of someone scrolling through the power settings showing that data. I'm not going to waste time typing it out.

ASSUMING you are referring to the values in this YouTube https://www.youtube.co​m/watch?v=hFEHZYxrPsc

Lumu values vs. YouTube values

Flashpoint Xplor 600
Full 1/250 vs 1/220
1/2 1/800 vs 1/740
1/4 1/1600 vs 1/1470
1/8 1/2700 vs 1/2352
1/16 1/4100 vs 1/3448
1/32 1/5400 vs 1/4651
1/64 1/6000 vs 1/6250
1/128 1/8200 vs 1/8130
1/256 1/8800 vs 1/10000

I re-ran the test of the Einstein E640 today. The fractional power numbers were basically identical but the full power numbers were significantly different and much closer to what Paul C Buff claims for them. When I bought the Einsteins used, the previous owner said they had been used very little and been in storage for a very extended period of time. I tested them as soon as I received them. They've now had a year-ish of heavy use and they're testing much faster than when they first awoke from ancient slumber.

The graph in the first post was updated but here it is for good measure:

2366 x 1044

EMBED PREVENTED, IMAGE TOO LARGE: https://i.imgur.com/Uu​nER7K.png Click here to see our image rules.

Found a source for flash durations of PCB products..

Here is the link for the Digi-Bee d800 ~~ https://www.konsul-instruments.com …c-buff-digibee-db800-218/

And below is a Einstein..


https://www.konsul-instruments.com …c-buff-einstein-e640-222/

sincity wrote in post #18507713
Found a source for flash durations of PCB products..

Here is the link for the Digi-Bee d800 ~~ https://www.konsul-instruments.com …c-buff-digibee-db800-218/

And below is a Einstein..


https://www.konsul-instruments.com …c-buff-einstein-e640-222/

The post and plot up top include an Einstein and an Alien Bees B400. The Einstein numbers you linked to are basically identical to mine (in Color mode) in terms of absolute time, so that's good confirmation that these are accurate numbers and the Einstein is fairly consistent from unit to unit.