Chromatic adaptation considering competing influences from emissive displays and ambient illumination is a little studied topic in the context of color management in proportion to its influence on displayed image appearance. An experiment was conducted to identify the degree to which observers adapt to the white point of natural images on an emissive display versus the color of ambient illumination in the room. The responses of observers had no significant difference from those of a previous experiment which was conducted with roughly the same procedure and conditions on a mobile display with a significantly smaller viewing angle. A model is proposed to predict the degree of adaptation values reported by observers. This model has a form such that it can be re-optimized to fit additional data sets for different viewing scenarios and can be used in conjunction with a number of chromatic adaptation transforms.