As a result of opposition, on the grounds of visual impact, to major wind energy installations on land, power companies are increasingly turning to off-shore sites for wind farm development. In most cases, the multiple turbines will be visible from the shore and hinterlands and opposition to the visual intrusion continues. This paper more firmly establishes the parameters of wind turbine visibility and impact at different distances from the viewer, under different lighting and atmospheric conditions and with moving or stationary blades. This is achieved through an on-line survey involving an 18 turbine wind farm at three different distances (4, 8 and 12 km), in five different lighting and weather conditions and in two different movement conditions. Distance and contrast were found to be very good predictors of perceived impact. There was a significant difference in impact between simulations with moving and stationary blades. Responses were also analysed according to local exposure, national exposure, interest level and age.