This contribution investigates whether machine-translated subtitles can be easily distinguished from human-translated ones. For this, we run an experiment using two versions of German subtitles for an English television series: (1)produced manually by professional subtitlers, and (2) translated automatically with a Large Language Model (LLM), i.e., GPT4. Our participants were students of translation studies with varying experience in subtitling and the use of machine translation. We asked participants to guess if the subtitles for a selection of video clips had been translated manually or automatically. Apart from analysing whether machine-translated subtitles are distinguishable from human-translated ones, we also seek for indicators of the differences between human and machine translations. Our results show that although it is overall hard to differentiate between human and machine translations, there are some differences. Notably, the more experience the humans have with translation and subtitling, the more able they are to tell apart the two translation variants.