Sayanora, did you set the base material to be 100% Self Illumination? Also you might need to bump the "luminance Scale" up to 1000. Also make sure reset the radiosity processing parameters and run it again. Also make sure the "Global Subdivisions Setting" is set to "enabled". Since Radiosity works better with dense meshes…
Malcolm what you are describing sounds similar to when I model things at a certain size and max feels it's too small. When I was making models for the ogre 3d engine the models had to be a certain size so they would fit in the world, but if I made them the correct size for ogre the zoom in Perspective would be all messed…