The Photomechanics15 conference brings together research communities in the field of optical measurement techniques and their application in experimental mechanics. Innovation is one of the key themes of Photomechanics15 as developments in advanced materials and structures, and the increased interest in biomechanics brings increasing challenges for measurement. Nowadays, nano- to microscale surface measurement techniques, provide surface stress/strain information under typical in-service loading conditions. Volume measurement techniques, operating in the micro to millimetre scale, provide detailed 3-D information for comparison with analytical and FEM models. Non-destructive testing is also rejuvenated by the new challenges of composite materials and the demands of process control, maintenance and repair of advanced materials.