Paul C. Buff, Inc. Technical Forum

I know it says you can't use the modeling light of the Einstein with the VML but you could use it with the
VLE here and their for a quick idea setting up?

Model Lamp Tracking means if I have the strobe at 1/2 power the modeling light will give a realistic representation of the flash? If I lower it down to 1/32 the modeling light will change accordingly?

Would the 150w bulb give a realistic representation of the Einstein flash at 1/2 power or would I need the 250w bulb?

FAQ says
Would the 25w bulb be able to show what 1/2 is as a modeling light?

First, we need to define what a model lamp does. It shows the direction the shadow will fall and the relative brightness as compared to other lights with properly set up model lamps.

Model lamps do not convey the actual brightness of the flash as they are too underpowered in most situations, and if they were bright enough, then why bother with the flash? Also, you have the difference in "burn time". A flash has a finite time it will emit light, where a model lamp can run indefinitely, and accumulating light over time. So it is impossible for them to be set "the same".

So on one flash, a 20W, 75W, 150W, 250W, or a 1000W model lamp will effectively tell you the same thing.

However, when using, say, two Einsteins and one is set to half power, and the other is set to 1/8 power, the difference in power can be seen from the different intensities in model lamps if they were each set to track.

Ah ok then. That makes sense. So the tracking would the track the power of the strobe givibg an idea of where the shadows would be. The case for a 250w bulb then would just be to output more light seeing the shadow dependent on distance.

So if using the VML the 25w would be ok?if using the Extreme you could get away with the 150w periodically.

Right. Another case for a 250W bulb would be in high ambient light situations where a lower wattage bulb may not be able to compete. Unfortunately, this is often in bright sun outdoors, when you would be running on a Vagabond.

The VML can keep up with 100W or so, but the battery will not last as long and the recycle times are longer. You can set the Einstein up to track, but decrease the model lamp power. The model lamp will still track, but at a lower than normal brightness. For example, you can have the E640 set to Full power and instead of the model lamp being at 250W, you can set it to 1/4 power, or ~63W. Then if you lower the flash output by one stop (320Ws), the model lamp lowers by a stop to 31.5W.

As you lower the flash output, the model lamp will continue to lower until it reaches its minimum power where it will stay if you keep reducing the flash output.

Incidentally, the reverse is true as well. You can have the model lamps track at a higher relative power than the flash power. This would be for low light/low flash situations where you still need to see or focus.

The specs say reading the VML:

Typically 400 to 500 shots per charge with 640 total Ws connected
Einstein™ units draw more power, discharging a fully charged battery in 8 to 12 hours of idling

So if I am using the modeling light as you say at 100w turning it on here and there to get an idea of the shot say in a 4 hour shoot. How much above would the specs change?

Like if I used the modeling light at 100w for 30 minutes off and on in a 4 hour shoot. Would I be ok? This wouldn't damage the battery just drain it?

I see, so I don't need to replace the 250w bulb with a lower watt. I can just turn down the power of the bulb/modeling light of my choice.

With the normal power consumption plus 100W for 30 minutes, you are using about half of your power for something other than recharging flash capacitors.




Yes. Just keep in mind a 25W bulb running at full power is more efficient, and therefore brighter, than a 250W bulb running at 25W. Also, color temperature will shift cooler (red/yellow) as you reduce power, but that should not be an issue.

Thanks for the help