In this paper we present results from an experiment designed to investigate the effects of image dynamic range on apparent surface gloss. Using a high dynamic range display, we present high dynamic range (HDR) and standard dynamic range (tone mapped, SDR) renderings of glossy objects in pairs and ask subjects to choose the glossier object. We analyze the results of the experiments using Thurstonian scaling, and derive common scales of perceived gloss for the objects depicted in both the HDR and SDR images. To investigate the effects of geometric complexity, we use both simple and complex objects. To investigate the effects of environmental illumination, we use both a simple area light source and a captured, real-world illumination map. Our findings are 1) that limiting image dynamic range does change the apparent gloss of surfaces depicted in the images, and that objects shown in SDR images are perceived to have lower gloss than objects shown in HDR images; 2) that gloss differences are less discriminable in SDR images than in HDR images; and 3) that surface geometry and environmental illumination modulate these effects.