Also consider your walls and ceiling surfaces.
Nice clean white walls and ceiling will reflect small amounts of artificial lighting.
1/3 of the lighting can be twice as bright in a space if you reflect this light correctly.
Look at how spray booths are lit so well with so few fixtures.
The same size space with stud walls and an open ceiling will be dark with twice the lighting.
As we all know good lighting is critical to a successful restoration project and the KEY element to painting. Glad we're discussing this Richard.