you could check the following: <h;_:
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- if the surface/element tilt is too large tv`b##
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- enough analysis rays used? 2g~ @99`
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- have you used Coherent Data option under Detector setting. (wu ciKQ
5!cp^[rGL
Someone above was right about that the non-sequential mode only uses geometric rays but you could see inteference fringes using Coherent Data.