Starting from the Middle Age and until the second half of the XIX century, many buildings in Cremona are characterized by the almost exclusive use of earthen mortars coupled with regular clay bricks. During the survey campaign on Palazzo Raimondi in Cremona, featuring a renowned Renaissance façade dating back to the late XV century, some mechanical in situ tests have been made on the walls of the basement and of ground floor in order to investigate the mechanical behavior of this earthen-mortar masonry and to compare it with regular lime-mortar brick walls. The results of those tests are here presented, together with the interpretation of the masonry behavior during the test by means of an optical recording technique that allows following step by step the absolute displacements of multiple selected points on the specimen.