Did Hans Memling Employ Optical Projections When Painting "Flower Still-Life?"

David Hockney has recently hypothesized that some early Renaissance painters employed optical devices such as concave mirrors to project images of a scene or part of a scene onto their supports, which they then traced or painted over. As one of many examples, he has claimed that Hans Memling (ca. 1440-1494) built an optical projector to create his "Flower Still-Life," specifically when rendering its carpet. The author's perspective analysis on the image of this carpet shows that, while there is a "break" in perspective consistent with refocusing or tipping of an optical projector, there are also other larger, more significant perspective deviations that are inconsistent with the use of a projector. After presenting a simple sensitivity analysis of these results and rebutting anticipated objections, the author concludes by rejecting the claim that optical projections were used in the creation of this still life.