I recently picked an ex88 rifa softbox to shoot talking heads. I recently tested it out and ran into an issue with hot spots on the subject's face. The silk on the rifa is 32x32 inches and I was also using the eggcrate. The source(1k) was about four feet from the subject. I didn't try using powder during the test. Is there anything else I can do with the softbox to avoid hot spots? Thank you for your insight and time!