Ok, time to lament. It turns out that I may have to pop the extra cash for the Voigtlander adapter after all. My Rainbow Imaging Nikon F adapter has a light leak right where the lens release metal tab is located. I am reasonably sure this is not a sample variation, instead -- it looks like a design flaw. I have the G-lens adapter which works fine for AI/AIS as well. I don't know if the non-G adapter suffers similarly or not. I have attached a pic to demonstrate how psychedelic lighting effects can result from the light leak (this was worst case scenario with light directly hitting the tab with camera in portrait orientation). If I cover the tab with my finger it goes away.