NOT A MACRO LENS
I wanted to experiment, so I ended up shooting extreme close ups without a macro lens. Images were not cropped in any way. What you see is a Sigma 28-70mm lens, set at 28mm with aperture all the way open at f/2.8. How did I get macro images with a wide angle lens? Try flipping it! I had to hold my lens up to my camera. ISO was set at H (3200) to give me enough light to eliminate handshake that was a major player as I was holding my lens against the camera body. As you can see I was able to get 1-2 inches away from the subject. It was an interesting experience. I realized that the plane of focus was very small. If you look at the Shift and Tab images, you can see plane of focus as a horizontal line of sharpness running through the image; only few millimeters wide.