Hi Wilt
Photo 15 is how I shoot the BD. Dealing with the ring on the background winds up like dealing with any hard edge modifier, I either feather only so far to keep the edge/ring off the BG, change the BG distance, shoot outside and/or do what ever it takes.
I noticed the double edge shadow when I first got the BD and notice quite often in glamor and beauty images. Umbra/Preumbra thingy.
I made my earlier comment because the outer bright ring was within the area seen by the lens, knowing that if you moved the light source back to make the background lighting less objectionable it would nevertheless alter the subject shadow and lighting due to the decrease in apparent size of the light source (beauty dish). I know you stated, "At 42" from subject, it's not what I would consider a good representation of true BD lighting"...what is the usual distance that you use to the subject?

