Paul C. Buff, Inc. Technical Forum

Hey everybody. Loving reading about all the technical information, and I'm also loving to read about the new VLX.

This is in response to the VLX beta tester thread. I received a VLX to test with my lights and did just that :D -- I posted the results of the test (if anyone is interested) as well as a small review of the VLX on my website.

You can read it here, and I am totally happy to answer any questions that anyone has about using the VLX.

Please let me know what you think, and if I missed anything in the review! Once again, thanks for letting me try out the VLX.

(Hope this thread is OK, as I don't exactly have any questions, but I wanted to share technical information and results from the VLX)

-- Andrew.

Andrew, Thank you for doing these tests. This is valuable info for us, and for customers.

A few observation on my part: The Scoro is a auto switching unit that automatically adjusts from 100VAC to 240VAC. Auto switching units, depending on the design, usually tend to recycle somewhat more slowly, or erratically, from inverter systems than do fixed voltage units. (This does not apply to Einstein™)

The Scoro is tremendously sophisticated, thus likely draws considerable power supply current in addition to the actual flash capacitor current. This tends to slow recycle times a bit.

Given these considerations, VLX™ obviously works with Scoro at 3200Ws. The recycle times are somewhat slower than with 4 Einstein™ units connected (2560Ws = 7.2 seconds) Please see complete video at various power setting and light units at:
https://www.youtube.com/user/paulcbuff

We have tested VLX™ with Dynalite power packs and measured the following recycle times:

1000Ws pack = 3.2 seconds, 2000Ws pack = 6.0 seconds.

I would suggest Andrew's tests (excerpted below) do validate VML's to very successfully operate perhaps the most demanding system out there.

Thanks paul. I do agree with the Scoro being absurdly sophisticated. It is quite complicated - sometimes to a fault. :P

I am really impressed with the VLX, and proud that I'll be able to use such a crazy system on battery from such an easy, small unit.

One thing I'm not sure about, though I would ask in hindsight. When recycling, the VLX makes a sort of 'whistling' noise (it's not exactly a whistle. Almost sort of a high pitched whine). Anything I should worry about, and is it specific to this system?

Here's the chart of recycle times for VLX™, VLM™ and Photogenic ION with multiple Einsteins and AlienBees from our youtube video at https://www.youtube.com/user/paulcbuff as accurately measured up to 2560Ws with one to four monolights connected. A must-watch for potential users.

Andrew, the whistling sound you are hearing is common, and is caused by high frequency vibration of the transformers and inductors in the VLX™ and similar devices. It's pretty much at the top of the human hearing range at about 20kHZ.

Small update to this. I took the VLX actually out into the field yesterday, as opposed to just doing garage recycle tests. Sometimes, if I raised the power of the Scoro in multiple stops, the unit would shut itself off when running from the battery. (Ie. Raised from power '4' to '8' and instead of charging up to 8, it would attempt to charge but the power pack would restart itself). Not sure why this would be happening, unless the Scoro is just trying to pull too much charge, can't get it fast enough, so it restarts. This seemed to happen more often when I was not in slow charging mode. In any case, this issue is completely fixed by raising the power more slowly- a stop at a time, waiting for the ready beep, another stop, waiting for beep, etc. It doesn't affect the firing at all.

Andrew, it figures it would do this less in slow recycle mode. In fast cycle mode the Scoro draws more peak current, which causes the voltage to drop more - enough for a logic power supply to reset.

Elinchrom multi-voltage lights are notorious for this sort of behavior with any battery supply when more than one is used.

Our Einstein multiple volage circuitry is designed by yours truly and does not exhibit this sort of issue ever.

That was my school of thought as well. Thank you for the information on the einsteins. VLX is still wonderful; I'll just have to be a little conservative with it!

Another small update today -- I posted part II of the VLX review and provided some sample final images! Again, really impressed with the VLX. Was able to shoot with it off and on for a good couple of hours and the battery barely reached half.

You can check out the final portion of the review here. http://www.a2mphotography.com/blog/2014 ... be-outdoor

One last time, THANK YOU so much to Paul and the team. :mrgreen: