Abstract: A between groups experiment was carried out to explore the effect of rendering quality on subjective impressions of illumination and perceived presence after exposure to a Virtual Environment (VE). The computer graphics scenes were rendered in varied levels of shadow accuracy utilising flat-shaded and radiosity rendering and were displayed on a stereo, head tracked Head Mounted Display (HMD). A total of 36 participants were exposed to each experimental visual condition and after completing a spatial task, they were given two questionnaires: A presence questionnaire and a questionnaire investigating subjective responses to lighting. Relevant results show a positive correlation between presence and subjective impressions of lighting (e.g. 'warm', 'comfortable', 'spacious', etc.) associated to the high-quality, full-shadow accuracy rendering condition. How real-world responses for both presence and lighting could be incorporated into a computer graphics simulation is still an open research question.