[log in to unmask] schrieb:
> Some interesting information about the photographic techniques used by Jim
> Henderson of Oregon City, Oregon to bring out faint and virtually invisible
> (to the human eye) inscriptions on historic rock art along the Oregon Trail
> can be found in the Northwest OCTA website at:
>
> http://nwocta.com/newsletters/99jul/kelton.html
>
> He is currently carrying out work for the Park Service at City of the Rocks
> in Idaho.  His technique, using polarized lighting and computer enhancement
> to bring out inscriptions on historic rock inscriptions, has wide ranging
> possibilities for both historic and prehistoric rock art panels, especially
> where it's difficult to discern images.
>

bit more reliable than barry fell?

geoff carver
http://home.t-online.de/home/gcarver/
[log in to unmask]