mas24 wrote:
If you prefer Nikon, go with the 105mm f2.8 macro. If you want to save some money, and still get a quality macro lens, go for the Tokina 100mm f2.8 macro. Both have 1:1 magnification. I have borrowed the Tamron 90mm f2.8 macro from a friend, but for portraits, not macro. All are full frame formatted lenses. The Tokina sells Brand New for $350. The new Tamron has a higher price tag. Between the Nikon and Tokina. Good luck.
I second mas24: I shoot a Nikon D750 and have the 105 mm f2.8 macro. It is a superb Nikon glass: tack sharp and built like a tank.