Introductory physics lab courses aim to have students gain a wide variety of skills and knowledge, including developing views of the nature of experimental physics that are aligned with common expert views. The large introductory lab course (~ 700 students) at the University of Colorado Boulder has been recently transformed to explicitly address this goal among others. To measure the level of success in reaching this goal, we used an established assessment instrument, the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS), which probes students' views and expectations of experimental physics. We collected students' responses to E-CLASS during three semesters before, and four semesters after, the course transformation. We observe statistically significant differences between the before and after transformation post-test scores of the (i) overall E-CLASS survey and (ii) some individual E-CLASS items, especially those closely related to specific course learning outcomes.