I'm going over some simple stuff for an astronomy exam and it occurred to me that I'm not sure what causes the tilt in the solar analemma. It won't be a question in the exam but it got me curious. It seems that the analemma has a different tilt in every picture I look at. I would assume that it depends on the time of day - an analemma photographed at mid day would be vertical and it would be more tilted the further from mid day you got. Is this right? Conceptually speaking, I can't think of any good reason for it to be tilted if the photograph was always taken at mid day.