Bowens 15000 power rating?

[Mark Sawyer]

I'm trying to find out the power rating for a Bowens 15000 moonlight. I've googled and binged it, but can only find a few conflicting claims from 350 ws to 1500 ws. Does anyone know? Thanks muchly! :)

[Taija71A]

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Hi Mark!

Bowens 15000 Monolight:

15000 Beam Candle Power Seconds (BCPS)...

or 'more importantly'... Only 300 actual Watt Seconds (W/S).

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Best regards,

-Tim.
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[Bob Salomon]

well first, watt seconds are not power ratings. For output of a flash you need to know guide number or BCPS or ECPS. All of those convert directly to an f stop, a watt second, or joules is the storage capacity of the flash. It will not convert to an output.

Lastly, you need to know at what angle of coverage the output is given for. With any given flash output the f stop will change with the reflector coverage as well as with the distance.

So, what you really want to know is what f stop does the flash deliver with say a 40° reflector at 10 feet. But also be aware that a bright, shiny reflector will have a higher output then a dull finished reflector. But the fall off from center to edge will probably be greater with the shiny reflector.

[Bob Salomon]

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Hi Mark!

Bowens 15000 Monolight:

15000 Beam Candle Power Seconds (BCPS) or 300 actual Watt Seconds (W/S).
--
Best regards,

-Tim.
_________

Nonsense, the output is dependant on the storage capacity of the capacitors, the diameter and length of the wires from the caps to the tube, the shape and design of the tube, the type and number of connectors between the caps and the tube, the type and design of the reflector and lots of other little things that prevent WS from telling you an actual output. In addition, no capacitors deliver 100% of their stored energy. 80% may be closer to the amount of output the caps can actually deliver to the flash tube.

And then that output will vary depending on the state of charge. Many flash units are not actually at 100% power when their ready light illuminates.

[Taija71A]

Nonsense, the output is dependant on the storage capacity of the capacitors, the diameter and length of the wires from the caps to the tube, the shape and design of the tube, the type and number of connectors between the caps and the tube, the type and design of the reflector and lots of other little things that prevent WS from telling you an actual output. In addition, no capacitors deliver 100% of their stored energy. 80% may be closer to the amount of output the caps can actually deliver to the flash tube.

And then that output will vary depending on the state of charge. Many flash units are not actually at 100% power when their ready light illuminates.

I didn't know that! :rolleyes:




For output of a flash you need to know guide number or BCPS or ECPS. All of those convert directly to an f stop...

No disrespect...

But, I guess that you failed to notice... That I already quoted the BCPS.
(*For the OP). :(





Bowens 15000 Monolight:

15000 Beam Candle Power Seconds (BCPS)...


It of course, is not my fault... That some Manufacturers and Distributors (*In your Industry) continue to use 'misleading' terms and comparisons as 'Marketing' Tools.



... but can only find a few conflicting claims from 350 ws to 1500 ws...

Bob, since the OP was only looking for a very 'Basic' Starting Point...
I chose to provide him with the information -- That he asked for.

'Nothing More and Nothing Less'.
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I am pretty sure that the OP already knows that a 'Watt Second'...
Is a derived unit of Energy... 'Equivalent' to the Joule.
--
Best regards,

-Tim.
__________

[Mark Sawyer]

Thanks, Bob and Tim!

Guide numbers seem useless unless you know what distance, ISO, aperture, and reflector are being used, and hardly anyone lists all of those. And hardly anyone lists bcps as a power rating, (on ebay right now, there's exactly one studio flash that gives its bcps, and that's searching both the descriptions and the titles).

So I'm stuck with watt seconds as an imperfect but general guide. Of course, many sellers can't differentiate between watt seconds and watts per second. And you have to know the individual flash system to know whether a 1000 ws system with two heads means 1000 ws at each head or if it's split between two heads at 500 ws each.

Trying to evaluate strobes is frustrating...