@SealBeard Your working distances as promised Sir,
"In each case the 55-200mm Lens was used with both the 11mm & 16mm Tubes plus a Raynox 250. These working distance measurements are all Exact In Focus measurements taken from the front element of the Raynox 250 to the in focus subject"
Lens set to 55mm = 50mm W/D at infinity focus setting, and 40mm W/D at closest focus setting.
Lens set to 200mm = 105mm W/D at infinity focus setting, and 95mm W/D at closest focus setting.
"Obviously all other focal length settings would be something in between to two sets of measurements I have done for you"
Hope this helps.,
George.