I just found out that my semi-macro Sigma 28/1.8 (1:2.9) can become a real macro together with the Kenko 2x TC that I bought for my 80-200/2.8L. Applying 1.6 crop factor and the 2x, it becomes amazing bigger than life 1:0.9! Furthermore, surprise, surprise, stopped down a bit, just as I want for more DOF, it is very very sharp! Precisely on par with my SHARP 50/1.8! I'm so excited about this discovery since I don't have to buy any macro lens. Yess! (Just slight sharpening)