Investigation of speckles produced from surfaces of some materials used in automotive industries with different wavelengths

The aim of this work is to present an overview about the speckles produced from many surfaces used in automotive industries using different illuminating wavelengths e.g. white light, Hg and Na light sources. In order to minimize the effect of the reflected speckle grains from such surfaces one has to calculate the speckle grain size and contrast at different wavelengths and the visibility of interference fringes obtained and also the roughness of the rough surface used. The speckles recorded at different angle of incidence for light used to achieve the proper scattering angles which gives minimum speckle brightness causing distortion of the formed image for a moment. Speckles produced from non-spectral light sources were photographed also to identify the difference between such pattern and the speckle pattern obtained with He- Ne laser light source and purely spectral light sources. The visibility of the interference fringe pattern obtained by speckle photography technique with different wavelengths has been investigated experimentally and theoretically.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.