Purple Fringing, and umbrella lighting

[flshwonder]

Hello everyone,
i need a bit of advice,
I need to shoot a fashion shoot on monday with limited equipment and my somewhat shallow knowledge.

i need for the person to be isolated on white, and her bottom foot is not necessarily important.

here is the equipment i have:
2 alien bees flash units with umbrellas
random desk lamps i can set up for extra lights
one reflector
sheets
window ambient light

in my attached photo i have one light behind the sheet, pointed at the back of it, and one umbrella pointed at the person, and some ambient sunlight coming through the windows directly behind me.
Is this a horrible idea? I'm getting some really bad purple fringing, but the subject needs to be able to move around freely, and i want the backdrop to be completely white. (and i plan to steam the sheet)

how can i pull it off??

[barabe]

You have more than enough at your disposition. First i would say to iron out that sheet to remove the possible shadows caused by the wrinkles. What kind of umbrella do you have? Is it shoot trough or reflector type? It does make a difference for the positioning of your lighting. I would put a light to the side of your model and point it to the sheet close range, to light it up brightly in a difuse matter witht the umbrella to make the sheet very white and place the other light on the other side pointing at the model a bit further away to eliminate the possible shadows on the sheet. The way you are going to light up your model on this side depends on what you need to acheive as a result. Is it going to be a direct lighting, are you using cookies? will you use a Gell to warm up or cool down the colors? Will you use an umbrella that is reflective or shoot trough. Play around with your gear is my best advice and share the results with us.

I hope i helped out a bit.

[Fotogreen]

It seems like you have enough lighting at your disposal but the end result is not satisfactory.

[kencaleno]

More contrast needed

[flshwonder]

Originally Posted by kencaleno

More contrast needed

i'm not looking for photoshop yet, I havent touched this in photoshop, but the main point is to get the lighting right first, and that's what i need help on

[flshwonder]

Originally Posted by Fotogreen

It seems like you have enough lighting at your disposal but the end result is not satisfactory.

yes, so what is a good way to arrange and use the lighting to get what i need?

[flshwonder]

Originally Posted by barabe

You have more than enough at your disposition. First i would say to iron out that sheet to remove the possible shadows caused by the wrinkles. What kind of umbrella do you have? Is it shoot trough or reflector type? It does make a difference for the positioning of your lighting. I would put a light to the side of your model and point it to the sheet close range, to light it up brightly in a difuse matter witht the umbrella to make the sheet very white and place the other light on the other side pointing at the model a bit further away to eliminate the possible shadows on the sheet. The way you are going to light up your model on this side depends on what you need to acheive as a result. Is it going to be a direct lighting, are you using cookies? will you use a Gell to warm up or cool down the colors? Will you use an umbrella that is reflective or shoot trough. Play around with your gear is my best advice and share the results with us.

I hope i helped out a bit.

what are cookies?
i dont really want direct light as in flash i guess, but id like for her to be lit nicely, no dramatic shadows, so diffused light will be on her at all times
no gels
probably reflective umbrella pointed at her

thank you so much for your advice!
so i guess what i can gather from this is that the light behind the sheet isn't the best placement?
the big problem too ,is that i dont have much room to shoot in, so i dont have much room to back up and get rid of any warping of her body through the lens because of the close proximity to her

[barabe]

a cookie is a piece of wathever you want that creates shadows where you desire them to be

The room is not a big issue, you want to be close with lighting using the reflectors. Like i mentioned play with your lighting to get the effect you need, practice makes perfect.

You have got pretymuch the right lighting in your shot called colorplay, just some tweeking to do.

[kencaleno]

Basically you need the model 6 feet in front of the sheet,to avoid shadows

Sheet needs to be front lit

Sheet needs to be lit 2 stops brighter than the model-For example sheet F11,model F 5.6

Ken