Technique Help!

[dalmorloson]

As some of you know I just got some lighting in the last couple days. My little girls had a friend come over and I had a guinea pig session with them. I was trying to get the white backround totally blown out while maintaining a proper exposure on the girls. I have a 580EXII on camera (no gear to get it off yet) and a strobe and halogen light on the backdrop. I was bouncing the speedlight off of a white ceiling that is 8 feet high. The girls were about 4 feet in front of the backdrop and I was probably 4-5 feet from them. I could get the back blown out but had so much spill that the girls kept coming out overexposed. This was the closest I could get to a proper exposure on the girls. How is this done? Do I need more room to get them away from the backdrop? I was out of room in both directions.



Canon EOS REBEL T2i
Exposure 0.005 sec (1/200)
Aperture f/6.3
Focal Length 33 mm
ISO Speed 200
Exposure Bias 0 EV
Flash On, Fired
Exposure Program Manual

[MrJones]

4 feet when lightning a white backdrop is just isn't enough.
when we do studio sessions we keep the model about 12-15 feet away. of course - that depends on the power of your light source as well, but you need to understand that a white background is like a huge reflector and it bounces the light back to the models.
did you try dialing down the power of the strobe and halogen unit?
btw, with bouncing the 580 EX II off the ceiling you've basically added more light behind them. what you did is to create a big light source (white ceiling) directly above them, so some light fell down in front of them and some behind them. you can see the lightning came from above by the shadows under their eyes.

[dalmorloson]

Thanks for your help. I kind of figured I had to get them away from the backdrop. I tried to lower the power of the backlights but I didn't get the blown out look. This was the least amount of light I could get on backdrop while still blowing it out. Unfortunately for the space I was in I guess its still too much for thr foreground.
My wife has been pretty good about me spending money on camera gear...wonder how she's going to react when I tell her we need a bigger house

[tyasa81]

Lol.. Its harder to blow out wih 3 subjects.. Have you considered just blowing out part of the backdrop thats directly behind them and do the rest in post? Thats what i did when i have more than 1 subject and trust me my house is apartment is small too

[kristenh]

i am by no means a strobist and i don't know about the back lighting and backdrop (though i did learn something today). But i do have a speedlight and wanted to recommend that you try bouncing that on the ceiling somewhat farther behind you (point it to the ceiling-wall corner behind you) or off the wall to the side (especially if it is a white wall, or shoot in raw in case you need to color correct if you happen to have red walls or whatever). the shadows are much more flattering that way.

[oldwolf]

Pull them away from the wall a little more and increase your f/stop. Keep everything else the same. Shutter speed controls ambient light and f/stop controls the light on the flash.