Equimolar copolymers of N-vinyl pyrrolidone with 1,1,1-3,3,3-hexafluoroisopropyl-a-fluoroacrylate were obtained by reversible addition-fragmentation chain transfer radical (RAFT) polymerization and by conventional radical polymerization (RAD). The copolymer conformation and compositional heterogeneity were analyzed by dynamic and static light scattering. RAFT copolymers of 41,000 M w 68,000 g=mol were shown to adopt cylindrical all-trans conformation. RAD copolymer of higher molecular mass (M w ¼ 390,000 g=mol) exhibited less extended conformation, thus indicating that the statistical Kuhn segment is less than RAD copolymer length.