how to create a light box environment?

Hi, I've been toying with photoworks environment images to change the lighting conditions. yet there are always "black spots" on my renderings no matter how I place my object. I supposse that is due to my placement and the dark parts of the image used.

How can I create a "light box" environment where minimal "dark spots" will be captured?

I create jewelery and watches and darkspots destroy the images.

Help? thanks!

SolidworksPhotoworks