With a lively yet rigorous and quantitative approach, Frederick R. Chromey introduces the fundamental topics in optical observational astronomy for undergraduates. Focussing on the basic principles of light detection, telescope optics, coordinate systems and data analysis, students are introduced to modern astronomical observation techniques and measurements. Cutting-edge technologies such as advanced CCD detectors and adaptive optics are presented through the physical principles on which they are based, helping students understand the power of modern space and ground-based telescopes, and the motivations and limitations of future development. Discussion of statistics and measurement uncertainty enables students to confront the important questions of data quality. With a purposeful structure and clear approach, this is an essential resource for all students of observational astronomy. It explains the theoretical foundations for observational practices and reviews essential physics to support students' mastery of the subject. Student understanding is strengthened through over 120 exercises and problems.