olemus
objektile teravnurga all suunatud valgus
https://dictionary.archivists.org/entry/oblique-light.html

rakendusi
- jälgede tuvastus ja uurimine
http://www.forensicsciencesimplified.org/photo/img/DSC_0008.jpg
- füüsiliste dokumentide visuaalne kontroll
http://slideplayer.com/slide/3914595/13/images/15/Document+Alterations+Chapter+15.+Obliterations%E2%80%94removal+of+writing+by+physical+or+chemical+means+can+be+detected+by:.jpg