[NTG-context] Opposite Blocks or Spread Based Layouts

Hi ConTeXt ComRaDes, Trying to design a travelogue book with photos on the left page, and text on the right. Tried \startopposite to get an opposite block, and turned it on with \setupoppositeplacing[state=start], to no discernable effect. Am I doing something wrong, or is there another way to do this? Any tips much appreciated. Corin Royal Drummond P.S. My poetry book is coming along nicely. I'll be sure to send along a link when it's finished.