Signed language users communicate in a wide array of sub-optimal environments, such as in dim lighting or from a distance. While fingerspelling is a common and essential part of signed languages, the perception of fingerspelling in varying visual environments is not well understood. Signed languages such as American Sign Language (ASL) rely on visuospatial information that combines hand and bodily movements, facial expressions, and fingerspelling. Linguistic information in ASL is conveyed with movement and spatial patterning, which lends itself well to using dynamic Point Light Display (PLD) stimuli to represent sign language movements. We created PLD videos of fingerspelled location names. The location names were either Real (e.g., KUWAIT) or Pseudo-names (e.g., CLARTAND), and the PLDs showed either a High or a Low number of markers. In an online study, Deaf and Hearing ASL users (total N = 283) watched 27 PLD stimulus videos that varied by Realness and Number of Markers. We calculated accuracy and confidence scores in response to each video. We predicted that when signers see ASL fingerspelled letter strings in a suboptimal visual environment, language experience in ASL will be positively correlated with accuracy and self-rated confidence scores. We also predicted that Real location names would be understood better than Pseudo names. Our findings show that participants were more accurate and confident in response to Real place names than Pseudo names and for stimuli with High rather than Low markers. We also discovered a significant interaction between Age and Realness, which shows that as people age, they can better use outside world knowledge to inform their fingerspelling success. Finally, we examined the accuracy and confidence in fingerspelling perception in sub-groups of people who had learned ASL before the age of four. Studying the relationship between language experience with PLD fingerspelling perception allows us to explore how hearing status, ASL fluency levels, and age of language acquisition affect the core abilities of understanding fingerspelling.