I use :
Numeric reflex camera : Nikon D70
Flash without connection : Nikon SB-800 (the Camera's integrated flash command the other flash that i hold in my hand)
Lens : Nikkor micro 105mm f2.8 (macrophotography)
Tripod
With the external flash, I shoot the eye of the
portrait, I hold the flash in the same distance from the coin than the lens. Usually, if you consider the coin like a clock, and for a
portrait right, I place the flash at about 1 o'clock (between 1 and 2). For
portrait left about 11 o' clock. Important : Do not use special macrophotography flashes, because you will not have any shadow and we need a little
bit of.
Camera setting :
aperture priority : f 16 (you can try 11 to 32 too, but 16 is
good !)
external flash
white balance : automatic
I take the picture in RAW (not yet processed) and after with the computer I correct the white balance and then i convert in Jpeg :
Left : White balance automatic, Right : manually
corrected white balance with "Nikon Capture"
The RAW files are much better for all the post-settings and allow to set the white balance after doing the picture. That allow to do a great exposure compensation too, much better than with jpeg files and with nearly any lost of
quality. To do the white balance you use a special
software, and you have just to show to the
software where is the white or grey to use as reference on the picture (I use a white page as background so I select the backgroud for the white balance).
Here is the final result :
With the 105 micro lens you can zoom until this point :
