Yes, Depth of field (Blender), is the same as Focus Deep (Octane), but in Blender you can set numbers as 12.5 , but not in Octane wich is limited to decimals, so you can only use 12,13,14,etc....
If DoF is set to zero in blender then there is no focus at all, I suggest to use a pick button to select where is the focal point, so you can choice an object or an empty for focus.