Paul C. Buff, Inc. Technical Forum

How long will a modeling tube stay on with a fully charged VML using one Einstein?

The VML cannot support an E640's 250W model lamp at full power, as it is a 120W inverter. It will lower voltage, so that the model lamp effectively becomes 120W. The VML will strain to keep up with the power draw of the light, and eventually overheat and shut down.

A fully charged battery running a model lamp at 120W would last roughly an hour, longer if the power is dialed down. I would not suggest running it at the full 120W for long periods, and make especially sure the unit has sufficient ventilation.

Would it be a good idea to switch it out for a 150w modeling lamp? I'm shooting some executive portraits outdoor and I just want to make sure it's going to hold up ok when making adjustments. Note: Majority of the time i've kept the modeling lamp off and i never had issues so i just wanted to get your input.

As long as the model lamp is dialed down to <120W, this would not be necessary. You can adjust the brightness of the model lamp independent of the flash power, even in tracking mode. On the back of the light, use the function button to scroll to the model window, then use the arrows up or down to adjust brightness. Then when you increase or decrease power, the model lamp will still rise or fall (within the limits of minimum and maximum output). This can also be done in the MODEL screen of the CyberCommander.



I am not sure if the model lamps will be useful or not. I presume you are also using flash, and the model lamps are for aiming purposes? If so, set your recycle indicators to turn the model lamp off, as the model lamp will slow recycle times. As well, if you are using flash, you are decreasing the run time of the VML. Overall, limit the time and intensity of the model lamps when using the VML.