Hi Brian,
Regarding the EOS
software: I assume on the main control panel you have selected 'Live shoot' and thus have the window open showing the image. You can do an autofucus from the 'Focus' box, but if you double click on the
part of the picture that needs best focus, another window
comes up with a close-up of that
part of the image. You can fine-tune focus with the arrows in the focus box.
Macro lenses don't magnify, they allow the camera to get nearer the subject and in that way make the image bigger. Modern cameras have a high enough resolution that you don't neccessarily need the coin to fill the frame. But for very small coins, especially if the camera is out of optical focus, the resolution may be insufficent. I prefer to get the picture as big as possible within reason, then when I resize it to a more realistic resolution, any errors are diminished in the same proportion.
I'm not sure what you mean about the lighting. What sort of light do you use? I will give an example of a typical set-up:
Let's suppose the coin has the
bust of an emperor. The camera is at a height that the coin fills half the frame. One
lamp is used. That
lamp is a so-called spot light i.e. it is
silvered on the back so that the light is somewhat directional (but not like a stage spot-light). That's not critical, but it helps increase the light level and helps the depth of
field. In the horizontal direction, the
lamp is positioned so that it points at the emperor's
face but slightly more at
his forehead, rather as you would a real-life
portrait. In the vertical direction, the
lamp should be about 24 inches above the coin, fairly close to the camera/copy-stand. Ambient light should be sufficently weak to have no effect. This set-up is a starting point. Experiment from that point. If the back of the emperor's
head is too much in shadow, then introduce a second
lamp on the other
side.
That's what works for me. Others may have different techniques. To illustrate the point, here's one I made earlier.