Background Lighting Issue

[melandkeifspics]

<p>I am trying to shoot a variety of different sized floral arrangements against a white wall. I'd like to keep the backgorund a light grey. What is the best setup to achieve a constantly grey background using a white wall using a three speedlite setup or any other setup given the chance? <br /><br />Right now, I've attempted shooting the arrangements with two speedlites through shoot through umbrellas setup at 45 degrees on either side of the subject and about 1 foot away. The subject is merely 2 feet away from the background wall and I've been getting very inconsistent results when it comes to the background color/exposure.</p>

[Matt Laur]

<p>Turn off the camera's auto ISO feature if it's on. Set the shutter speed, lens aperture, and flash power all manually. Adjust to taste, and then it will not change from shot to shot.</p>

[melandkeifspics]

<p>I'm using all manual settings. The issue seems that everytime I change the flowers, the background is affected. I'm assuming that the colors of the flowers and their size is casting weird shadows and colours that are affecting the backgroiund wall that is relatively close. I don't have a large space to work with. Just a tiny 10x10 room. What do you suppose is happening with my background considering all camera setting are constant?</p>

 

[howard_m]

<p>I'd try to get teh flowers farther away from the bkgnd and maybe use a slightly longer lens to compress depth. Raise the flashes a bit and point them downwards to shorten any shadows.</p>

<p>Also, there is only a 2 stop difference between the light falling on the subject and the light hitting the bkgnd.</p>

[ellis_vener_photography]

Add some space between the subject and background and light the background separately.

[kilian_kunz]

<p>Light the background and the object separately. The foreground light should not effect the background. More space between should help. Ubrellas for a even bg light is ok.</p>