Crosstalk is a cause of a major perceptual problem in the 3D display system shown itself mostly as ghosting. In this work we aimed at investigating how much perceived crosstalk that is acceptable for the end-users in movie type contents played by 3D projection systems. Two types of 3D projection systems (one system using active shutter glasses, and the other system using passive polarized glasses) were compared in the experiment. The study included an objective measurement of crosstalk in the 3D projection system and a subjective users' experience of the visible distortions. The results shows that 10% can be considered as a crosstalk threshold for end-users not to be annoyed (MOS<3.5) by the distortions and thus acceptable. The distortions start to be perceived at about 3% crosstalk. The study found a linear relationship between perceived crosstalk and the amount of crosstalk. The perceived crosstalk also varies largely depending on the video contents.