Digital SLR camera with either a macro lens or a standard lens and extension tubes.
Sheet of glass
A strong directional light source (such as a desk lamp will be fine)
Transmitted light photographs
Place the sheet of glass so that overhangs a table edge. A stack of books on the sheet of glass will help to keep everything stable. Place the stamps on the sheet of glass. Put the camera on a tripod, position this over at the stamps perpendicular to the plane of the stamps. The depth of field of lenses used for macro photography is very shallow so stop the lens down to f8- f11. Light the stamps from underneath the sheet of glass, for best results this needs to be indirect, i.e. the light is shining on to the underside of the stamps at an angle, not in line with the lens axis.
Turn off all other light sources in the room to reduce reflected light. Take the photograph.
Dark field photographs
The setup is as above except the stamps are placed on black card and lit indirectly from above.
Try both techniques, stamps vary in their response to these different techniques.
Supplementary image development
Open the image
Correct the exposure
Increase the saturation and contrast to maximize the visibility of the watermarks.
by Keith Collins