Paul C. Buff, Inc. Technical Forum

Today I received the 230v VML inverter I had ordered earlier this week. I ordered it expecting it would provide marginally improved recycling times with my Einsteins and better compatibility with non-PCB multi-voltage strobes. Initial testing this evening with the new inverter and one of my Einsteins has yielded extremely disappointing results. Contrary to expectations, the 230v inverter is providing recycle times approximately 60% longer than the 115v inverter.

Although the difference is readily observable, I wanted to quantify the results. To do this I recorded videos of the Einstein + VML at full and half power using both inverters. A video editor was used to determine the time at which the flash fired and the time at which the ready light re-illuminated. The following spreadsheet shows the results:



The calculated recycling times are bolded in the above spreadsheet.

Is this behavior normal? I could not locate a follow-up post from Paul to this one:

viewtopic.php?f=8&t=826&p=5469&#p5469

Dave F.

wow, i would have clearly thought the opposite would happen: i.e. faster recycling times due to a higher voltage. Does this have anything to do with the einstein's internal menu feature which you can change the value of the specs in the einstein?

thanks for doing the test dave.

Something wrong here. They should recycle Einstein at about the same rate as 120V versions. I'll ask TS and engineering to verify and follow up and post a reply. I've seen reports that the 230V Mini will power multi voltage Elinchroms better the the 120V version.

I'll also have them bring me a 230V version and follow up myself.

More info here

viewtopic.php?f=8&t=1520

We'll follow up as promised.

Tetrode,

OK . . . Here's what I got from Tech, and I will verify over the weekend. Seems like there is a heat sensitive component causing a slow initial current limiting that straightens out after a few shots. I see the same thing, on a much smaller scale, on 120V VMLs . . . about a 10% reduction in cycle times after 10 or 20 shots.

We'll get engineering and the inverter vendor on the issue and get it corrected . . . but it takes time for the vendor to make changes.

Paul,
I just tested a fresh out of the box 230V VML on our showroom E640.
Initially, I was getting about 6.5 second recycle time, for about 10 shots.
I then used the E640 normally kept in my office. I plugged the E640 into the
VML and turned both on. They sat for about 5 minutes with no model lamp as I
took a phone call and figured out my intervalometer. I set the
intervalometer to fire once every 10 seconds. By this time, the inverter had
warmed, and the recycle times started at about 4-5 seconds, then dropped to
near 3 seconds within the first 10 shots. I then took the now warm VML to
the showroom and tried again on that light, and got about 3-4 sec recycle
times again. I do think I heard Mike mention that before, that the 230V
recycle times drop significantly as the inverter warms in the first few
minutes.

Thanks for the quick follow-up, Paul. Based on what your tech told you, I retested the 230v inverter this afternoon. Using the intervalometer in my D700, I instructed the camera to shoot 40 frames at 10-second intervals. Each shutter release fired an Einstein (set to full power)connected to the VML with the 230v inverter. After the 40 pops, I repeated part of yesterday's test. I made a video and calculated recycle times using a video editor.

I can confirm what your tech reported. The warmed up inverter recycled the Einstein more quickly than it did yesterday when it was cold. The difference is dramatic as can be seen by comparing the two yellow columns in this spreadsheet:



So, when warmed up, the 230v inverter is capable of providing slightly improved recycling times over the 115v inverter. Unfortunately, when first powered on, recycling times are unacceptable. As the timing for a revision to the 230v inverter is (understandably) indeterminate, I will have to exchange my 230v version for a second 115v version.

Dave F.

One last test:

This time, I started with an idling VML (230v inverter) that had been powered on for approximately 3 minutes. Again, using the D700 intervalometer, an Einstein at full power was fired 20 times at 10-second intervals. The entire sequence of 20 pops was recorded and recycling times calculated. Plotted, the results look like this:



As can be seen, between the 17th and 18th pop, recycling time drops by more than 1 second. From that point, recycling times continue to trend downward. Based on my prior tests, I would expect the warmed up and stabilized 230v VML to provide recycling times in the vicintiy of 3.5 seconds.

Dave F.

Paul, I was wondering if you could provide an update on this issue. Has the "cold inverter" problem been corrected? I would really like to give the 230v inverter another try.

Dave F.

The issue has not been resolved. However, we are still working on it.

Thank you for the update.

Dave F.