Orders $300 and over eligible for free ground shipping within the 48 contiguous states!

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Einstein™ Flash Unit

SKU: E640
Eligible for FREE Shipping for orders over $300!


The Einstein™ Flash Unit features action stopping flash durations, color consistency, and the broadest power range. The flexibility of the power range allows for everything from over-powering the sun, to shooting indoor portraits with a wide-open aperture.

Perfect for: Professional photographers in any field.

Sync Cord Compatibility: All Paul C. Buff, Inc. flash units arrive with a 15' sync cord for connecting to a camera's PC sync terminal. Not all camera's are equipped with a PC sync terminal. If you plan on using this cable, and not wireless remotes, you may need a hot shoe adapter. Check your camera's compatibility

Find out how the Einstein compares to our other flash models.

9 f-stop power variability (2.5 Ws to 640 Ws)
Adjustable in precise 1/10 f-stops
All-digital control from LCD display
Global plug-and-play from 95 to 265 VAC
Action stopping flash durations as short as 1/13,500 sec. (t.1)
Color consistency +/- 50K at any power
Bright, adjustable 250 W modeling lamp
Frosted dome cover reduces UV emission
Audible and visual recycle indicators
Compatible with all BUFF light modifiers, light stands, CyberSync™ remotes, and Vagabond™ systems
Frosted Pyrex dome
Einstein™ shipping cover
250 W modeling lamp
15' sync cord (1/8" to PC)
15' power cord
30-Day Absolute Satisfaction Guarantee
2-Year Factory Warranty
Einstein™ Product Manual

Product Video

Product Specs

  Einstein™ Flash Unit
Watt seconds 640 Ws
Power Variability 9 f-stops (full to 1/256 power)
Recycle to Full 1.7 sec.
Flash Duration (t.5) 1/2000 sec. (at full power)
Flash Duration (t.1) - in Action Mode 1/588 sec. (at full power) | 1/13,500 sec. (at 1/256 power)
Flash Duration (t.1) - in Color Mode 1/588 sec. (at full power) | 1/8,000 sec. (at 1/256 power)
Power Requirements Automatic power switching from 95 to 265 VAC, 50/60 Hz (no lamp change or user attention required)
Average Current Draw Brief initial recycle surge current of 8.5A; average draw of 8A
Sync / Trigger Voltage Less than 5 volts (safe for use with DSLR cameras)
Modeling Lamp 250 W, 120VAC bayonet-style quartz bulb
Flashtube 12mm flashtube (daylight-balanced and UV-coated
LCD Display Back-lit, high-resolution color LCD. 320x240 pixels; 2.4 in.
Stand Mount Fits stands up to 5/8 in.
Umbrella Mount Accepts umbrella rods up to 9mm
Weight 4 lbs. 5 oz.
Dimensions 7 in. (height) x 5.4 in. (diameter) x 7.8 in. (length)

Dimensions Note: length measurements taken from the front of the shipping cover (in place on the unit’s faceplate) to the back panel; height measurements taken from the top of the umbrella screw to the bottom of the light stand top coupler, folded back underneath the unit; width measurements taken from side to side at the widest points