tamron 17-50mm f2.8 vc
My understanding is that you can use adapter going down (i.e., 77 to 72), but not going up.
For zoom lenses, especially at the wide end, it is important to use thin CP.
I have the tanron 17-50 non-vc and I use a thin Nikon CP-10 which is 67mm to fit the tamron. No problem with vignette at all at wide end.