I agree with SPP, the shots are very good! Your setup is very similar to mine. I'm using a Canon Rebel EOS T3i with a 100mm macro lens on a tripod. I use a single side lamp with a daylight 5000k 1100 lumens bulb. I put the coin on a jet black background and use the timer on my camera for a 2 sec delay. The settings on my camera yield a photo that is a bit underexposed on purpose. Then I can adjust the exposure on the image to get the color right. As with you, my closeups are enlargements of the full coin shot.