Light setup help

[mbellot]

Hoping I'm in the right section for this...

I was asked (last minute) by an old friend to help set up lights for some photos of her dancers this Saturday, late morning. She normally has a photographer available, but they can't make it this time.

They will be individual, full length, posed, blown out white background, possibly with props (she can't decide).

Good news is she owns the lighting equipment, and it's a decent stuff. Two WL X3200s, two B1600s, two 86" white umbrellas, two 68" white umbrellas and four stands. I own a light meter which will hopefully take some of the guesswork out of settings. I've never worked with more than three cheap lights and have never tried to blow out a background.

I'm hoping someone here can help me with a rough diagram for light placement and aiming, particularly for the background so I don't get a bunch of light spilling back on the dancer. I've read you want to aim for ~ 2 stops more light on the background vs subject, so I'm guessing the X3200s will be for the background.

I haven't been to her studio in years, but if memory serves the room is roughly 15x30 with reasonably tall (10-12 foot) ceilings. The one issue I can see is one of the long walls is mirrored from the ground to about seven or eight feet high. I'm guessing this will need to be covered to prevent unwanted reflections.

Thanks!

 

[Wilt]

1. Light the subject fully from the front (near lens)...this is your Fill
2. Light the subject more intensely (by about +1EV intensity relative to Fill intensity) from about 45 degrees from the subject...this is your Main
3. Lights positioned per bullets 1+2 will provide 3:1 Main:Fill subject contrast, a 'moderate' contrast level
4. IMPORTANT: Have subject position far enough from backdrop to be able to not have much shadowing cast on it by the subject illumination
   
   and INDEPENDENTLY light the background so that the intensity of the backdrop is +2EV relative to subject illumination provided by source 1.
   If the backdrop is white, the backdrop illimination source can be +1 in relative incident intensity; if gray backdrop, the illumination source needs to be +2 in relative incident intensity.

Doing #4 will be somewhat complicated by the fact that you may not be able to hide the background light from camera lens by placing it behind the subject, and need to position it off to one side outside the view of the lens, and that causes light falloff gradient from side to side, meaning that you need to have TWO sources, one to either side of the subject position. If it is possible to use only one background illumination source, placing that one source HIGH above the view of the lens and centered behind the subject would be a way to hide the background source if your ceiling is high enough above a standing subject {and the vertical gradient mimics what our mind expects from illumination coming from high up).

With those side wall positions (distances), the intensity of reflected light from the side walls is not likely to have deleterious effects serious enough to worry about...the drupoff due to distance will make the contribition of reflected unwanted lght on the subject to be small fractions of EV compared to the direct distance between Main/Fill and subject
If the side walls do contribute too much straynlight (not expected to be the case)...the walls themselves are inefficient reflectors relatively, and that decrease in intensity is made greater simply by distance to the wall and back to the subject..., put black panels to either side near the walls

 

[mbellot]

Thanks for the answers, unfortunately we were half way through setup when you posted.

We got the job done, not quite to your specifications but "good enough" that she was happy with the pictures we took.