Results 1 to 6 of 6

Thread: Bowens 15000 power rating?

  1. #1
    Mark Sawyer's Avatar
    Join Date
    Jul 2004
    Location
    Stuck inside of Tucson with the Neverland Blues again...
    Posts
    6,269

    Bowens 15000 power rating?

    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!
    "I love my Verito lens, but I always have to sharpen everything in Photoshop..."

  2. #2

    Join Date
    Jul 2010
    Location
    Ontario, Canada
    Posts
    667

    Re: Bowens 15000 power rating?

    __

    Hi Mark!

    Bowens 15000 Monolight:

    15000 Beam Candle Power Seconds (BCPS)...

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

    --
    Best regards,

    -Tim.

    __________

  3. #3

    Join Date
    Sep 1998
    Location
    Loganville , GA
    Posts
    14,410

    Re: Bowens 15000 power rating?

    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.

  4. #4

    Join Date
    Sep 1998
    Location
    Loganville , GA
    Posts
    14,410

    Re: Bowens 15000 power rating?

    Quote Originally Posted by Taija71A View Post
    __

    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.
    Last edited by Bob Salomon; 13-Mar-2015 at 14:10.

  5. #5

    Join Date
    Jul 2010
    Location
    Ontario, Canada
    Posts
    667

    Re: Bowens 15000 power rating?

    Quote Originally Posted by Bob Salomon View Post
    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!


    Quote Originally Posted by Bob Salomon View Post
    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)
    .


    Quote Originally Posted by Taija71A View Post

    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.


    Quote Originally Posted by Mark Sawyer View Post
    ... 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'.
    --
    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.

    __________

  6. #6
    Mark Sawyer's Avatar
    Join Date
    Jul 2004
    Location
    Stuck inside of Tucson with the Neverland Blues again...
    Posts
    6,269

    Re: Bowens 15000 power rating?

    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...
    "I love my Verito lens, but I always have to sharpen everything in Photoshop..."

Similar Threads

  1. converting Profoto zoomspot to Bowens?
    By big_ben_blue in forum Gear
    Replies: 0
    Last Post: 25-Sep-2011, 11:32

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •