I used DPP.
Select the photo in the main window
Press Edit Image Window button
Hit 100% view for images smaller than the viewing window (like this one)
Refer to the histogram:
If the image is overall too dark, press the first tone curve assist button
If still overall too dark, press the tone curve assist + button
Adjust the Saturation to match the look of the coin, always erring on the side of less enhancement
Adjust Sharpness to taste, always erring on the side of less enhancement
Adjust the dark tones with the left slider on histogram until the darkest shadows of the coin are pushed to black
Adjust the highlight tones with right slider on histogram until the brightest highlights are pushed to saturation
Contact me for photographic equipment or visit my home page at:
http://macrocoins.com