After many trials i have concluded that I simply cannot house my Af-105-VR in my particular port/ housing setup because and extension of the lens means I must switch to a multi-piece port that the AF 105 wont fit in. However, unlike the 105 I can simply remove the limiting switch on the Sigma 150 and it will fit.
The result is that I am going to give the Sigma another try in Wakatobi in February.
On my first try it did not seem that the 150 mm gave me much more working distance over the 105 because the lens is longer. Therefore, using a subsee, the 105 seemed superior. However, I only spent 1 day with the rig. Any other experiences out there?
In addition an opinion was previously posted that whereas at 1:1 the 150 does not give more magnification than the 105, at less than 1:1 it will. Any experience with that?