REPRODUCTION RATIOS ON STANDARDIZATION …

1 THE INFLUENCE OF MEDICAL photography S WESTMINSTER REPRODUCTION RATIOS ON STANDARDIZATION IN FORENSIC photography AN OPINION HoosainM EbrahimDepartment of Medical Illustration and Audio Visual ServicesUniversity of LimpopoSouth AfricaPHOTOGRAPHYF orensic MedicalDifferent aims Different objectivesLegal purposeFORENSIC PHOTOGRAPHYF inal photographic product (may only be the beginning)Photographer s involvement in a legal system that might want to knowWHY, WHERE, HOW, WHEN and under WHAT CONDITIONS the images were takenForensic photographs must meet the following: Technical qualities Sharpness of detail Clarity of image Use of lighting Perspective Accuracy of REPRODUCTION of both colour and form The medical provides a precise record is comparable with others taken over a period of time is obtained with the least inconvenience to the patient meets the intention of the request is in accord with current methods of presenting medical dataSTANDARDIZATION FACTORS Film emulsion / Digital Lighting Backgrounds Viewpoint Scale Perspective Colour Processing Printing Presentation Orientation (forensic) Identification (forensic)

2 STANDARDIZATION REQUIRES WORKING TO PRE-DETERMINEDRULESWORKING TO SCALEThe scale of REPRODUCTION must be constant for any given area both at the recording and printing stageWESTMINSTER REPRODUCTION RATIOS FOR STANDARD ANATOMICAL REGIONSREPRODUCTION RATIOSFull length1:50 Chest1:151:15 Abdomen1:151:15 Forearms1:151:15 Both feet1:10 1:10 Head and neck1:10 Face1:8 Both eyes1:4 Genitalia1:3 Teeth1:2 Single eye1:135mm formatmicro 55mmlens 105mmView from above. Diagram explaining why photographs taken from different distances show different contours of the head. Short-distance photographs do not show coronal contours and portions of the of contourcameracameraTHE HEAD AND FACEV iews: Antero-posterior (AP) Postero-anterior (PA) Left and Right oblique(45to median plane) Left and Right Lateral(90tomedian plane) Inferior(Worm s-eye view) Superior( Bird s-eye view) STANDARD REPRESENTATIONAL VIEW IMAGINATIVE EVIDENTIAL AND TEACHING VIEWFRANKFURT HORIZONTAL / PLANE Aplanedefinedbythreeosteometricpoints, Itisusedtosystematicallyorienttheskull.

3 (ConventionheldinFrankfurtin1884)MEASURI NG LINEAR PROJECTIVE (inFrankfurtHorizontal).COMPARISONS BETWEEN FACES MAY BE MADE TO: identify offenders identify missing persons confirm or refute claims of identity study the relationship between the skull and the overlying soft tissue develop diagnostic methods for facial syndromesFACIAL LANDMARKSCan be used: toestablishpointsofreference toidentifyfeaturesdefiningthecranial-fac ialgeometryofhumans toperformreconstructiveorcorrectivesurge ry byforensicartiststoidentifytheremainsofi ndividuals,orwhentheycomposeage-adjusted photographsofmissingchildrenLANDMARKSG labella(g)themostprominentmidlinepointbe tweentheeyebrowsandisidenticaltothebonyg labellaonthefrontalboneTrichion(tr) (eu)themostprominentlateralpointoneachsi deoftheskullintheareaoftheparietalandtem po-ralbonesVertex(v)

4 Thehighestpointoftheheadwhentheheadisori entedintheFHCRANIOFACIAL SURFACE / SKELETON LANDMARKSv vertextrtrichioneueuriong glabellazyzygiongo goniongngnathionpg pogonionslsublabialechcheilioncphcristap hiltrisnsubnasaleal alareprnpronasaleor orbitaleex ectocanthionen endocanthionft frontotemporalescisuperciliaregnpgslchsn alorexexfttrvtrgeuzygogognzyeuscienengal prngocphchORIENTATION Differentanglescancauseunnecessaryconfus ion Consider:(a)cameratothesubject(b)areaofi nterestonthebody(c)orientationofindividu albodyparts(d)standardizationrulesPOSITI ONING OF SKULL Skull holding jig Pan-and-tilt device Camera mount Supporting railsSTANDARDIZATION OF SKULL PHOTOGRAPHS IN PERSONAL IDENTIFICATIONS BY PHOTOGRAPHIC SUPERIMPOSITION Relationshipbetweentheimageoftheunidenti fiedsubjectandtheoriginalphotographicpor trait Centralprojection(distancebetweencameraa ndtheheadorskullthatresemblesthedistance oftheoriginalphotograph)

5 Posture Magnification PerspectiveBITEMARK EVIDENCE Standardizedphotography Scaleofreference Teethmodelsandwaxbase Overlays Fluorescentimageanalysis Changesinthedermalandepidermaltissues Tonelinebitemarkphotography Useofvideotape Useofalternativelightsource 450nmCOMPARISON photography BASED ON STANDARDIZATION IS CRITICAL IN FORENSIC SCENE RECONSTRUCTION ACCURATE MEASUREMENTS COMPARISON PURPOSESTHE INFLUENCE OF MEDICAL photography S WESTMINSTER REPRODUCTION RATIOS ON STANDARDIZATION IN FORENSIC photography AN OPINION HoosainM EbrahimDepartment of Medical Illustration and Audio Visual ServicesUniversity of LimpopoSouth Africa