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Thread: Big dark room, fast moving dancers, flash - need some advice

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    Big dark room, fast moving dancers, flash - need some advice

    Hi Al

    I'm planning a job creating pictures of dancers. I have this big real dark room - matte black floor, wall and ceiling, black curtains. I have one or two dancers at a time and they are moving fast.
    The room is about 100x100m. I will mark a spot/an area on the floor where i catch the dancers.

    I will put light on the dancers with studio flashes. I have fou Bowens (2 x 500ws + 2 x 400 ws).
    Havent figured out how many flashes i will use.

    Question
    What kind of reflectors do I need for these flashes. I want to isolate the dancers in this big dark room.

    Appreciate any help :-)

    -- Søren

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    Moderator Dave Humphries's Avatar
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    Re: Big dark room, fast moving dancers, flash - need some advice

    Quote Originally Posted by slm View Post
    What kind of reflectors do I need for these flashes. I want to isolate the dancers in this big dark room.
    Hi Søren,

    Unless the room is very well lit, or the flashes are too far from the dancers, I doubt you'll have a problem there, in fact it could end up looking like they were shot outside at night.

    However, I'm no expert, but hopefully someone that has done this kind of thing will be along shortly.

    I am thinking you may need to pre-focus (and leave it on manual) on your "X" marks the spot too - I can't imagine AF working quickly enough.

    Good luck,

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    Re: Big dark room, fast moving dancers, flash - need some advice

    Hi Dave

    Thanks for your respnse.
    I'm from the age of no-autofocus and often use this pre-focus technique and it actually work.
    I have loved my nikons for many years, but fast autofocus isnt their strong side :-)

    OK, my goal is to isolate the dancers in the dark - literally. So my job is to put some nice light on the dancers. My guess is that the light shouldnt be spread too much - but a snoot is probably too narrow. Or could I use a snoot and move it a bit far from the dancers?

    -- Søren

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    Re: Big dark room, fast moving dancers, flash - need some advice

    With a room 100x100metres I doubt if you will have any problem isolating the dancers from the background if you keep them away from any wall ... "X" being perhaps in the middle of the room. In this you are aided by the Inverse Square rule of light which means that very quickly the light falls off in power with distance from the flash .... the example I usually use shows at five feet one might use f/11 and at ten feet one uses f/5.6 and at 20 feet f/2.8. So if you have light power to use f/11, or whatever aperture you are using, for the shot at 20feet behind little or nothing will register, particularly with black floors and backgrounds.

    For somebody working in a small area there would be need to control the lighting with flags and snoots but with your large area I see no problems .... Not had the opportunity to do something like this but the simple ISR calculations form my opinion It is somewhat like taking flash photos in the open at night which I've done many times.

    Your query about moving the lights back to light a larger area when using a snoot .... I would suggest that you make a simple cardboard 'snoot' to control the spread of light rather than moving back which will reduce the power of the flash, which likely you will have already done to achieve the fast 'shutter' speed or quick short flash of light to freeze the dancers. I have not used your studio flashes but I gather they have quite a long duration when used at full power so I see using several at reduced power to gain the brief flash required to freeze fast dancers. Another possible problem is sync and suggest a longish shutter speed to make sure you catch the brief flash [ long as 1/60 rather than 1/250 ] ... I am assuming here that there will be little ambient light in the room.
    Last edited by jcuknz; 14th February 2013 at 09:09 PM.

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    Plumcrak's Avatar
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    Re: Big dark room, fast moving dancers, flash - need some advice

    I don't have any knowledge of what you are attempting but I wait with anticipation to see the results. Sounds really interesting and something I might want to try at some time

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    Re: Big dark room, fast moving dancers, flash - need some advice

    Quote Originally Posted by slm View Post
    I'm planning a job creating pictures of dancers. I have this big real dark room - matte black floor, wall and ceiling, black curtains. I have one or two dancers at a time and they are moving fast. The room is about 100x100m. I will mark a spot/an area on the floor where i catch the dancers. I will put light on the dancers with studio flashes. I have fou Bowens (2 x 500ws + 2 x 400 ws).
    WARNING:

    You need to be aware that STUDIO FLASH units have a relative LONG FLASH DURATION (compared to modern HOT SHOE FLASH units).

    Therefore you need to address potential issues of the likelihood of capturing SUBJECT MOVEMENT.



    ALSO - the Maximum Flash Sync Shutter Speed of your camera, when using STUDIO FLASH UNITS will most likely be about a stop slower than that which is specified in the user manual, as that speed is for a dedicated HOT SHOE FLASH.

    So, as a practical example - I am using my 5DMkII and the Maximum Flash Sync with my Elinchrom Studio Flash Units is about 1/160s ~ 1/180s – for a shooting scenario comprising “one or two dancers at a time and they are moving fast” I would choose to use dedicated Hot Shoe Flash Units, because I now that using my Elinchroms will render Subject Movement for a moderate running speed.

    ALSO note that consideration of the Rise and Fall Time of the Studio Flash Units needs to be taken into account; as this rise and fall time, in concert with the SLOWER maximum Flash Sync Speed of the camera WILL exacerbate the likelihood of capturing SUBJECT MOVEMENT.

    Note also that some specs only give a computed ‘Peak Flash Period’ as the ‘Flash Duration’.

    WW
    Last edited by William W; 15th February 2013 at 10:07 PM. Reason: corrected spelling

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    Re: Big dark room, fast moving dancers, flash - need some advice

    I was just thinking more on this-
    Also note that the Flash Durations given in the Specifications are ‘indicative’ – the actual duration will vary with number of: Flash Heads used; Configuration; Power Supply; Power set at each Head and also Age.

    WW

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    Re: Big dark room, fast moving dancers, flash - need some advice

    Flash duration will probably be shortest at the lowest power settings...

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    William W's Avatar
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    Re: Big dark room, fast moving dancers, flash - need some advice

    . . . which could make a different problem, if the Heads need to be a distance away (from the dancers) - i.e. 'too far away' to make the Aperture or ISO which is desired.

    WW

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    Moderator Manfred M's Avatar
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    Re: Big dark room, fast moving dancers, flash - need some advice

    This sounds like an exciting project and with a huge room, you will have lots of space to set up and work. I assume that you are planning to work without backdrops, so that the dancers are the only things that are lit up, with the large room swallowing the light. I take it that there won’t be any ambient light that will be bright enough to influence your shots.

    I guess my first question would be is why you want the dancers to come through quickly. I assume you are willing to trade off a posed shot for a scene with action in it? I expect you will be shooting at a fairly small aperture to give you reasonable DoF to make sure that the dancers are in focus. My guess is that you will likely be shooting up to three lights; a key, a fill and a rim.

    Your choice of light modifiers will influence what the scene ends up looking like. You do have to decide on a look when you are figuring out your lights. A large softbox that is close to where the dancers are being photographed will result in a soft, even light. Using something with a harsher and highly focused light like a reflector, perhaps with a reasonable wide angle grid spot, will result in a more contrasty look with rapid light fall off. I think you will need to use a rim light to ensure some separation of the dancer(s) from the background in a room that large, so you might want to try that with either a grid spot or a strip box to see which one works better.

  11. #11

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    Re: Big dark room, fast moving dancers, flash - need some advice

    Hi all

    Thanks for your answers and input. I've been on the road for a couple of days, therefore the late response back.

    The studio flashes have a bit longish duration. It's 1/900th (for the 500ws) and 1/1000th (for the 400ws) at full power probably less at less power.

    Whether or not this is sufficient depens of whether the dancers are moving straight across viewing direction or they are moving towards me. I'm drawing different setups to figure out the placement of the light, me and the dancers.

    After thinking and a talk with one more experenced guy, my starting point is a big beauty dish with a grid. The quality of this is that it gives a fair column of light pretty directed by the grid. As the second light I have a fairly deep reflector (18cm) with three different grids (1/8" 3/8" and 1/3"). This gives a norrower column but also quite nice directed.
    The dish-with-grid will be placed fairly high (a boom approx 0.5 - 1 m above dancers head). The smaller reflector with grid used for a sort of rim light from the back.

    The diffence in distance flash-to-dancer of the two flash heads - i hope I can regulate within the scale of the each flashhead. Not that big a worry though.

    I have the option of a try-out-the-setup day at the room and I will try out the setup with some variations.

    I have though a thought of an alternative setup with "small" flashes (Nikon SB-800). But it another game, both as for the light power and the reflectors I have available. But it's a thought that runs as a background job in my thoughts :-)

    -- Søren

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