A digital camera having an acoustic member includes a first cover, a water-proof sheet and a second cover. Non-silicon light-sensing devices in a least a portion of a crystalline material can output electrons generated by light absorption therein. With a simple bias retarder, the effects of anterior segment retardance can be removed from a single polarimetric image of the retina without a VCC. A method for blocking scattered light in a lithography system using multiple pattern generating devices is also provided.