24 January 2011 Performance of extended depth of field systems and theoretical diffraction limit
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Proceedings Volume 7876, Digital Photography VII; 787607 (2011) https://doi.org/10.1117/12.872459
Event: IS&T/SPIE Electronic Imaging, 2011, San Francisco Airport, California, United States
Extended depth of field (EDOF) cameras have recently emerged as a low-cost alternative to autofocus lenses. Different methods, either based on longitudinal chromatic aberrations or wavefront coding have been proposed and have reached the market. The purpose of this article is to study the theoretical performance and limitation of wavefront coding approaches. The idea of these methods is to introduce a phase element making a trade-off between sharpness at the optimal focus position and the variation of the blur spot with respect to the object distance. We will show that there are theoretical bounds to this trade-off: knowing the aperture and the minimal MTF value for a suitable image quality, the pixel pitch imposes the maximal depth of field. We analyze the limitation of the extension of the depth of field for pixel pitch from 1.75μm to 1.1μm, particularly in regards to the increasing influence of diffraction.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Nicolas Bachelard, Frédéric Guichard, Frédéric Cao, and Imène Tarchouna "Performance of extended depth of field systems and theoretical diffraction limit", Proc. SPIE 7876, Digital Photography VII, 787607 (24 January 2011); doi: 10.1117/12.872459; https://doi.org/10.1117/12.872459


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