Paul C. Buff, Inc. Technical Forum

I use three Einsteins for my low-light FallingWater portrait series. I also use Profoto and wrote a comparison 18 months or so ago, coming away very impressed with the Einstein. (http://kevsteele.com/blog/profoto-einstein-lighting/). As I look at the latest series coming from Broncolor and Profoto I see serious specmanship. Talk of 1/25,000 sec pulse durations. Now I realize these are t.5 times (t.1 can be estimated for most packs as 3 times slower). I've been looking, looking for meaningful data to compare t.1 pulse durations versus power. For example that Pro B4 pulse of 1/25,000 would be a t.1 pulse of about 1/8000 but at 1.0 WS. At full 1000 WS power that Pro B4 is a t.5 duration of 1/2000 (t.1 estimated at 1/600).

I'm looking to find the best solution for short durations at higher power to complement the Einsteins for outdoor action work where I need full power from multiple strobes. I've heard the Elinchrom Ranger speed packs are the opposite in terms of pulse duration: shortest pulse at max power. I would love to hear more on this.

Some specs I found - (it really is harder than it should be to nail down mfg specs)

Broncolor Move 1200L
min power t.5 1/12,000 t.1 1/8,500
max power t.5 1/1,000 t.1 1/375


Profoto Pro-B4 1000
min power t.5 1/25,000 t.1 1/8,500* est.
max power t.5 1/2,000 t.1 1/600* est.

Are you looking to use more than one head per pack? If so, then two E640's would have the same power per head, and as fast or faster flash durations than listed for these systems. Alternatively, depending on what you do, you may be able to use more than one E640 head per location.

Are you looking to stop action or fully sync with fast shutter speeds on medium format (or trying so sync faster than x-sync on a DSLR)?

Yes, stopping action, generally limited to shutter speed of 1/250. I may drop ambient a stop or two but not excessively. I've though about doubling up E640s. Let's say I'm OK with a t.1 of 1/2000th, that would be a stop down or 320WS in action mode. Two E640s next to each other brings me to 640 WS at 1/2000th. Three would be 1000 WS at 1/2000th.

The scenario works if I'm using reflectors for modifiers (hard light). It becomes a challenge if I want to soften the light with an Octa or PLMs, it just becomes a bank of two or three big modifiers which could be unwieldy on location not to mention the extra grip, stands etc needed.

I know you've published some nice curves of typical monolights (t.1 duration vs power) but a lot of photographers are taking these Einsteins into scenes replacing packs and heads. I would love to see you test the Elinchrom Rangers and Quadras, the Profoto B4 and Acute 600, the Broncolor Move and Hensels. It would be great to be able to compare these options and know where I stand at T.1 duration with each one at say 1000 WS and 500 WS etc. Yes the B4 is an $8000 pack but I may realistically be using it in rental situations.

Alternatively, I would also love to see a rugged 1280 WS Einstein or if heat is an issue a lithium based pack & head solution :-)

Remember this, which you may already know: The flash duration of a light, regardless of how fast it is, will not freeze any blur from ambient light contribution. It is very likely you will have ghosting from movement from any one of these lights.

That's fine, motion blur is an important part of the feeling of dynamic motion and I can control that with my ratio of ambient to strobe as well as firing the strobe at the rear curtain of the exposure. But the strobe does need to freeze the final action which outdoors requires the higher power and ideally a t.1 of a 1/2,000 or faster.

Why a Bronco Move instead of a Scoro?

If you want fast action stopping and high power, the Scoro makes more sense IMHO...
Full power has a t.1 of 1/500ish, and min power of 1/10000, but you should be ok around half power to 1/3 power (they don't supply any charts)-:

For ambient control, skip the DSLR and use something like a Canon G12 or Panasonic LX5 and you'll get sync speecs up to 1/700...