I teach beginning digital photography at a junior college. I got a lot of my lecture materials from the department head when I was first hired. I have modified them over the years and added my own. I still teach these new photographers about crop factor, image circle sizes, "full frame" and so on. But I began to wonder recently if this is even necessary? If you originally shot with film, it was important to understand that a 24 MM lens on early DSLR would not give me the same field of view as I was used to. So the crop factor and doing the conversion was important to understand what I would get and what lens I needed to buy. Why did I need that 12-24? Oh! The crop factor. Yes. But nowadays, no one is coming from film, and no one (well, darn near no one) is buying a "full frame" camera first. I teach that 40-50mm lenses are about "normal." I teach that very near the beginning and don't get into crop factor until later, when my students have a better feel for their cameras. They learn that 28 and lower are wide angle lenses. 24-28 are moderately wide, 10-20 are very wide. They don't have any frame of reference in their minds to need to know that a 10mm lens "looks" like what a 15 mm lens gives on full frame. That point is lost on them. Anyway, this is a very long explanation to ask: Do new photographers really need to understand crop factor? Why or why not?