It is very difficult to come up with a blanket statement about the amount of light needed since conditions vary a lot from one show to the other. Without having prior knowledge of the context in which you are planning to project, it is impossible to give a determine how much light is needed. However, experience has shown us that in most cases (tours and large scale events), you should aim for a minimum of 300 lux reflected by projection surfaces. We suggest a minimum of 100 lux for surfaces in architectural video projection contexts (video projected on buildings at night).