1The use of shading and the projection of shadows to show perspective in architectural or technical drawing.‘These methods differed from contemporary pictorial practices by their greater science - particularly the use of shadow projection (skiagraphy).’
- ‘His first process, sciagraphy or photogenic drawing, had been an invention.’
historical The use of X-rays as a diagnostic tool.
- ‘skiagraphy showed a foreign body, hardly as large as the little fingernail’
Late 16th century from French sciagraphie, via Latin from Greek skiagraphia, from skia ‘shadow’.