Although touch screens are becoming the center stage of interaction between users and systems, operating them with our fingers creates problems of finger occlusion and imprecision. The situation worsens with the trend of device miniaturization and content enrichment. Taking into account the facts that an area is formed when the finger contacts the touch screen, and that this area is subject to change depending on who is using it and how it is used, this study proposed a technique that uses a dynamic-sizing finger probe for on-screen object selection and display magnification via visualization scaling to solve the aforementioned problems. This study also compared the proposed technique to the conventional touch technique using objective and subjective measures. The results showed that the proposed technique had shorter movement time with small targets and densely packed distracters and had lower error rate under extreme conditions. The initial arm movement of the proposed technique was also affected less by the fine adjustment in the proximity of the target. Participants preferred the proposed technique over the conventional one in terms of smoothness, accuracy, speed, fatigue, and ease of use.The proposed technique and the result of this study can be applied to the interaction design of systems in which selecting a target from a group of densely packed distracters is a commonplace, for example, selecting a point of interest (POI) on a global positioning system (GPS).